Video line inversion to reduce the influence of periodic interference signals on analog video transmission

Abstract

Video system (900) featuring: a signal receiving circuit arrangement (928) designed to: Receiving a first section and a second section of a video signal (906) transmitted by a transmitter (910) over a video link; and a receiver logic (926) trained to: Determining a phase difference between a noise signal (908) in a first video line (102) of the first section of the video signal (906) and the noise signal (908) in a second video line (102) of the first section of the video signal (906); when it is determined that the phase difference is within a predefined range, providing a signal to the transmitter (910) to generate the second section of the video signal (906) by inverting a subset of several video lines (102) of a transmit input video signal (412); Modifying the second section of the video signal (906) received by the signal receiving circuit arrangement (928) by inverting that subset of the multiple video lines (102) of the transmit input video signal (412) which was inverted by the transmitter (910) to generate the second section of the video signal (906).

Description

Technical field of disclosure

[0001] The present disclosure relates to the field of video transmission and in particular to analog video transmission. background

[0002] Video-based applications that rely on capturing video information in real time, such as automotive infotainment, advanced driver assistance systems (ADAS), autonomous vehicles, and security monitoring systems, generally involve capturing and generating video data using one or more cameras. These cameras may include charge-coupled devices (CCDs), complementary metal-oxide semiconductor (CMOS) image sensors, or other suitable video recording devices that, generally speaking, convert incident photons into digital video data (raw data or pixels). In such applications, the video data typically needs to be transmitted from the camera to other devices for processing in real time. These devices may include, for example, electronic control units (ECUs) or components in communication or alarm systems.Such devices can, for example, run specialized software to perform processing and analysis tasks based on the captured image and / or video data and deliver corresponding outputs. The combination of layers of transmission infrastructure that enable the transfer of data between the camera and the video data receiving device / processor can be referred to as a "video link" or "camera link".

[0003] A multitude of factors can influence the cost, quality, and robustness of a video connection. Physical limitations such as space / surface area, as well as regulations, can impose further constraints on the requirements or specifications for video connections, necessitating compromises and innovative solutions.

[0004] US 3,676,589 A concerns the near-complete elimination of interference in a video channel caused by the horizontal sync pulses of another adjacent video channel, whereby the video portion of each composite video signal is inverted in every second frame before transmission. Then, at each receiver, the video is inverted again to recover the original video signal. As a result, the interfering horizontal pulses reverse their polarity in successive scan frames and are therefore largely neutralized due to the integration effects of the human eye.

[0005] US 5,025,312 A relates to a method and apparatus for reducing transmission path noise within a video signal, so that a noise-reduced image is produced on a display. The method comprises the steps of: a. extracting low-amplitude image details and transmission path noise from the video signal; b. recirculating a fraction of the extracted low-amplitude image details and transmission path noise; c. combining the recirculated fraction with the extracted low-amplitude image details and transmission path noise to compensate for the extracted low-amplitude image details and thereby separate the transmission path noise; d. subtracting the separated transmission path noise from the video signal in the absence of movement of the associated image content to denoise non-moving image areas of the video signal; and e.Selective coring of only the moving image areas of the video signal to denoise these moving image areas, whereby noise in non-moving image areas is reduced by signal recirculation and in moving image areas by coring.

[0006] JP 2002 - 41 003 A relates to a liquid crystal display device and a method for driving a liquid crystal with reduced power consumption when driving a TFT liquid crystal display array. The solution relates to a liquid crystal display device in which a common electrode, arranged to face each pixel electrode of a liquid crystal display array, is supplied with a common signal Vcom, the polarity of which is reversed in each predetermined cycle by a common signal generator circuit. Each sampling line is supplied with a sampling signal at a predetermined sampling time by a sampling driver, while each sampling line is supplied with a display signal VD by a signal driver with alternative polarity reversal at the time of the polarity reversal of the common signal Vcom.A central electrical potential of the display signal VD, which is fed into the signal line, is shifted in the inverted polarity direction relative to a polarity reversal direction of the common signal at the time of the polarity reversal of the common signal, so that the amplitude of the common signal Vcom is suppressed to approximately a source voltage for driving a logic circuit. Brief description of the drawings

[0007] To provide a more complete understanding of the present revelation and its features and benefits, reference is made to the following description in conjunction with the accompanying figures, where identical reference symbols represent identical parts; they show: Fig. 1 a schematic representation of an exemplary video signal according to some embodiments of the present disclosure; Fig. 2 a schematic representation of an AC-coupled circuit in a single-ended transmission scheme according to some embodiments of the present disclosure; Fig. 3 a schematic representation of an AC-coupled circuit in a push-pull transmission scheme according to some embodiments of the present disclosure; Fig. 4 a schematic representation of a periodic interference noise signal that affects the analog transmission of a video signal; Fig. 5 a schematic representation of a noise signal that is out of phase with video lines, according to some embodiments of the present disclosure; Fig. 6 a schematic representation of a noise signal that is in phase with video lines, according to some embodiments of the present disclosure; Fig. 7 a schematic representation of a noise signal that is in phase with video lines and a video inversion implemented by a transmitter and a receiver, according to some embodiments of the present disclosure; Fig. 8 a flowchart of a method for operating a system configured to implement video line inversion for a video signal transmitted over an analog video link, according to some embodiments of the present disclosure; Fig. 9 a block diagram representing an exemplary video system according to some embodiments of the present disclosure; and Fig. 10 a block diagram representing an exemplary data processing system according to some embodiments of the present disclosure. Description of exemplary implementations of the revelation. Overview

[0008] The systems, methods, and devices of this disclosure each exhibit several innovative aspects, none of which alone is responsible for all the desirable properties disclosed herein. Details of one or more implementations of the subject matter described in this disclosure are set forth in the following description and the accompanying drawings.

[0009] Disclosed herein are systems and methods that use video line inversion to reduce the influence of periodic interference signals (e.g., electromagnetic interference (EMI)) on the analog transmission of video signals over wired links / connections. Such systems and methods may be particularly suitable for, but are not limited to, use in a vehicle (where the term "vehicle" includes not only wheeled vehicles such as a car, truck, or bus, but also, for example, an airplane, aircraft, or spacecraft), in a surveillance system, or in any other environment where a transmitter located at one location in such an environment (e.g., in a vehicle) and a receiver located at another location in such an environment may need to exchange video signals and other data over a wired connection in analog format.Video signals can be captured, for example, by an image sensor in a camera that is communicatively coupled to the transmitter. Although this disclosure mainly describes video connections and video signals, the video line inversion described herein is also applicable to image signals or any combination of video and image signals transmitted over an analog transmission channel.

[0010] In one aspect of the present disclosure, a video system comprises a transmitter configured to send an analog video signal to a receiver. Under certain circumstances, a transmitter may be configured to perform a video line inversion for a specific subset of video lines of a video signal before the video signal is sent to the receiver, and a receiver may be configured to perform a corresponding inversion for the same subset of video lines of the video signal received at the receiver. Such video line inversion performed by the transmitter and receiver may advantageously enable the reduction or elimination of the effect of periodic interference signals that might affect the video signal during transmission, resulting in improved video quality rendered at the receiver.For example, a receiver can be trained to receive the first section of a video signal transmitted by a transmitter over the video link and determine a phase difference between a noise signal in the first video line of the first section and the noise signal in the second video line of the first section. Such a phase difference indicates a line-to-line phase difference (i.e., a phase difference from one video line to the next subsequent video line) in the noise signal within the first section of the video signal. If the phase difference is determined to be within a predefined range, the receiver can be trained to modify a second section of the video signal received by inverting a subset of several video lines within the second section.The receiver can then render the received video signal for display.

[0011] As used here, the first and second sections of a video signal refer to different parts of a given video signal transmitted from the sender to the receiver. The first section is the part of the video signal that the receiver can use to determine whether a video line inversion might be advantageous, for example, based on the noise-signal phase difference determined for the first part of the video signal received at the receiver. On the other hand, the second section is the part of the video signal transmitted by the sender that implements a video line inversion, for example, in response to the receiver indicating to the sender that such a video line inversion would be beneficial.That the transmitter performs a video line inversion on a specific subset of video lines of a video signal (namely, on a specific subset of video lines of the second section of the video signal) before the video signal is sent to the receiver, and the receiver performs a corresponding video line inversion on the same subset of video lines of the video signal received at the receiver, can advantageously enable the reduction or elimination of the influence of periodic interference signals that could affect the video signal during transmission. In some embodiments, the line inversion can be performed digitally on both the transmitter and receiver sides (i.e., the line inversion can be applied to digital signals).

[0012] Other aspects of the present disclosure provide methods for operating such a system as well as computer-readable storage media that store instructions which, when executed by a hardware processor, cause the processor to execute the methods for using video line inversion to reduce the effect of periodic interference in the analog transmission of video signals.

[0013] As those skilled in the art will recognize, aspects of this disclosure, in particular aspects of the implementation of the video line inversion proposed herein, can be embodied in various ways—for example, as a method, system, computer program product, or computer-readable storage medium. Accordingly, aspects of this disclosure can take the form of an embodiment composed entirely of hardware, an embodiment composed entirely of software (including firmware, resident software, microcode, etc.), or an embodiment combining software and hardware aspects, all of which may generally be referred to herein as a “circuit,” “module,” or “system.” Functions described in this disclosure can be implemented as an algorithm executed by one or more hardware processing units, such as one or more microprocessors of one or more computers.In various embodiments, different steps and parts of the steps of each of the methods described herein can be performed by different processing units. Furthermore, aspects of this disclosure can take the form of a computer program product embodied in one or more computer-readable media, preferably non-volatile, on which a computer-readable program code is embodied, e.g., stored. In various embodiments, such a computer program can, for example, be downloaded (updated) to the existing devices and systems (e.g., to the existing video transmission systems, in particular to the existing analog video transmission systems including transmitters, receivers, and / or their controllers, etc.) or be stored during the manufacture of these devices and systems.

[0014] The following detailed description provides various descriptions of specific embodiments. However, the innovations described herein can be implemented in a multitude of different ways, as defined and covered in the claims or selected examples. The following description refers to the drawings, in which the same reference numerals may denote identical or functionally similar elements. It is understood that the elements shown in the drawings are not necessarily drawn to scale. Furthermore, it is understood that certain embodiments may have more elements than are shown in a drawing and / or a subset of the elements shown in a drawing. Additionally, some embodiments may have any suitable combination of features from two or more drawings.

[0015] Other features and advantages of the disclosure will become apparent from the following description and claims. Analog video transmission

[0016] To illustrate the video line inversion techniques described here, it may be helpful to first understand phenomena that can arise in analog video transmission. The following basic information can be considered a basis upon which the present disclosure can be adequately explained. This information is offered for explanatory purposes only and should therefore in no way be interpreted as limiting the broad scope of the present disclosure and its possible applications.

[0017] In systems that require the transmission of video data between system elements (e.g., between an image sensor and a processor implemented at a certain distance from the image sensor), such as surround-view ADAS or (security) surveillance systems, the video data captured by the camera can be transmitted digitally, e.g., as a serialized digital bitstream, which may be in the form of RAW data as captured by the image sensor, or in a processed form, e.g., as YUV data generated by an image system processor (ISP) that performs demosaicing of the RAW image sensor data. Alternatively, the video data captured by a camera can be formatted into an analog signal before transmission and then transmitted in analog form.

[0018] Analog video signal transmission can offer advantages over digital transmission. The serialized nature of digital transmission means it requires higher bandwidth than analog transmission. Meeting these higher bandwidth demands necessitates a more expensive infrastructure. While bit accuracy is maintained in digital transmission and can be compromised in analog, the impact of errors in digital transmission on output video quality can be far greater than in analog transmission. Therefore, transmitting the original digital video data as an analog signal offers several advantages over digital signal transmission. A system based on analog transmission can provide reduced costs and more robust transmission.Although the image sensor generally outputs digital video data, this can be converted into an analog signal for further processing and transmission to a receiver via an analog video link.

[0019] Although this is known in the prior art, a brief explanation of an example formatting of video data is given below.

[0020] In a typical camera, color is created by filtering the light that strikes each photographic area (or pixel) to produce either red, green, or blue values. The arrangement for the different colors (i.e., color patterns) of the most frequently used photographic areas is called a "Bayer pattern." RAW data from a single image captured by a camera in this way (where a video is a sequence of images) represents the value of each pixel for pixels of different colors. In other words, for a single image, RAW data can contain pixel values ​​for all red pixels (i.e., pixels designed to filter incoming light to detect wavelengths in the spectrum associated with the color red), pixel values ​​for all green pixels (i.e., pixels designed to filter incoming light to detect wavelengths in the spectrum associated with the color green), and pixel values ​​for all blue pixels (i.e., pixels designed to filter incoming light to detect wavelengths in the spectrum associated with the color green).Pixels are designed to filter incoming light to detect wavelengths in the spectrum associated with the blue color. Each pixel can be characterized by an intensity or size, among other things, and is represented by a number of bits (e.g., 10 bits) used to represent the magnitude of a signal captured / stored in a specific pixel for a particular component.

[0021] RAW data can be processed to create components that are then transmitted in a video signal. For example, red, green, and blue values, or a processed version of these values, are examples of different components of a captured image, collectively referred to as the "RGB" color space. RAW data can be interpolated, a process called demosaicing, and then converted by an ISP into other types of color spaces, such as "YUV" color spaces, where Y is a luminance component carrying the intensity of light information, and U and V are chrominance components carrying the color information. A single video frame can consist of a matrix of individual pixels of one or more components. In some implementations, different components can be transmitted over different channels.Unless otherwise stated, the descriptions given herein may refer to pixel values ​​of a specific component or any combination of components.

[0022] The pixel values ​​of a single video frame (the pixel values ​​or pixels sometimes referred to as "active pixels" to indicate that they contain values ​​representing a single video frame captured by a camera) can be grouped into horizontal lines, referred to here as "video lines," and these video lines can be grouped or stacked vertically to form a single video frame. The screen is built up sample line by sample line by sending the pixel values, represented by appropriate component values ​​(e.g., RGB or YUV values), over the video link. However, simply having a stream of components, such as a stream of RGB colors, is not sufficient to know which part of the stream belongs to a particular pixel (e.g., the top-left pixel) on a display.To solve this, two additional signals are added to the video signal, containing the values ​​of the active pixels to be transmitted. One is a signal containing pulses for horizontal synchronization (horizontal sync pulses), and the other is a signal containing pulses for vertical synchronization (horizontal sync pulses). A horizontal sync pulse provides a reference for different video lines (i.e., it indicates a line start point), while a vertical sync pulse provides a reference for different video frames (i.e., it indicates a frame start point). A horizontal sync pulse (or simply "horizontal sync") can be a pulse inserted into a video signal before a stream of pixel values ​​for a particular video line begins, and / or when a video line has finished (but it is typically inserted before a video line begins).Thus, the term "video line" refers to active pixel data (i.e., pixel values) for a line of a video frame, with this data contained in a video signal between two successive horizontal sync pulses. The two successive horizontal sync pulses can then be said to be "associated" with the video line. A vertical sync pulse (or simply "vertical sync," sometimes called a "vertical retrace") can be a pulse or sequence of pulses inserted into a video signal when all video lines of a particular video frame have completed and / or before video lines of a new video frame begin. Thus, each frame boundary can be delimited by a single vertical sync pulse or sequence of pulses.Since each line of a frame has the same number of pixels, the time between successive horizontal synchronization pulses is constant. Since each full frame (i.e., a frame with all its lines) has the same number of pixels, the time between successive vertical synchronization pulses is constant. In this way, horizontal and vertical synchronization pulses allow the determination of which color component of the video signal corresponds to which position to be displayed on the screen. All common analog video transmission schemes mimic this organization of pixels in a frame, marking the line start and frame start times with a horizontal synchronization pulse and a vertical synchronization pulse, respectively.

[0023] Fig. Figure 1 shows a simplified example of an analog (video) signal, demonstrating how horizontal synchronization pulses (100) can be included in the video signal to be transmitted. As shown in Fig. As shown in Figure 1, 100 active pixel data points can be contained between each two consecutive horizontal synchronization pulses, which are stored in Fig. The lines 102 and 104 are designated as video lines (i.e., sections of the video signal that carry the video data for two consecutive lines of a video frame). Pulses 100 are called horizontal sync pulses because they indicate the starting point for the active pixel values ​​that would be rendered as a horizontal row of pixels. Vertical sync lines (not shown in this example) indicate the start of a new video frame (within which the multiple subsequent video lines, i.e., horizontal rows of pixels (data), share a common vertical starting point). Typically, but not necessarily, the horizontal sync pulses occupy the lowest part of the signal range.A flat section 106 immediately before a given horizontal synchronization pulse 100 is called the "front blanking shoulder," and a horizontal section 108 immediately after the horizontal synchronization pulse is called the "back blanking shoulder." These sections can be set to certain predefined signal levels (e.g., both can be set to a voltage level of zero) and then used to identify the horizontal synchronization pulses 100 within a video signal. Together, the front blanking shoulder 106, the horizontal synchronization pulse 100, and the back blanking shoulder 108 are referred to as the "horizontal blanking interval" (HBI).

[0024] When addressing the question of how video signals can be transmitted from a sender to a receiver, when implementing analog signal transmission over a wired transmission line, a choice can be made between AC and DC coupling (the latter is also referred to as "conductive coupling").

[0025] AC coupling requires the use of at least one coupling capacitor, which is an additional component compared to DC coupling, where such capacitors are not required. An AC-coupled wired transmission line between a transmitter and a receiver typically has a first coupling capacitor located downstream of the transmitter and upstream of the transmission channel, and a second coupling capacitor located downstream of the transmission channel and upstream of the receiver. The term "coupling capacitor," as used here, can refer to one or more coupling capacitors. In contrast, DC coupling uses only resistors or simply wires and no coupling capacitors, and therefore DC coupling may be preferred due to its simpler implementation and lower cost and space requirements.

[0026] Furthermore, one or more coupling capacitors, together with the termination resistors at both ends and the impedance of the wired transmission cable, can act as a high-pass filter, thus attenuating the transmission of low-frequency components of the analog signal. This is relevant for video signal transmission because the frequency spectrum of such signals often contains DC-level and low-frequency elements that would be susceptible to such high-pass filtering, resulting in a loss or distortion of image information. Therefore, it is desirable for a video signal to be preserved down to a very low frequency and down to the DC-level components.This means that coupling capacitors used for AC coupling may need to be large enough to minimize the cutoff frequency of the high-pass filter formed with the receiver termination, and / or some other ingenious techniques may need to be used.

[0027] Although AC coupling may be considered an undesirable option due to capacitor size requirements, it can be particularly advantageous in certain applications because it offers improved tolerance to some fault conditions. This is the case, for example, in automotive / vehicle applications, where reducing the risk of damage during a short-circuit-to-battery (STB) fault condition can be a motivation for AC-coupled video links. Because DC voltage levels are blocked, AC-coupled links are inherently resistant to STB faults. Therefore, transmitting video signals in an AC-coupled analog signal format can be a cost-effective and robust transmission option, especially in automotive applications.

[0028] In various embodiments, the video line inversion techniques described herein can be used with either AC-coupled or DC-coupled analog transmission.

[0029] In some embodiments, the video line inversion techniques described herein can be implemented in systems that employ AC-coupled analog video transmission. In various embodiments, an AC-coupled transmission line for carrying video data can be implemented according to either a single-ended or a push-pull pair transmission scheme. In some implementations, the push-pull pair video transmission can be particularly advantageous because it may benefit from lower noise susceptibility compared to the single-ended video transmission.

[0030] In some embodiments of a single-ended implementation of an AC-coupled transmission line, a corresponding coupling capacitor may be arranged on each end of a push-pull transmission line, i.e., one coupling capacitor between a transmitter and a conductor of the line, and another coupling capacitor between that conductor and a receiver. In some embodiments of a push-pull implementation of an AC-coupled transmission line, a pair of coupling capacitors may be arranged on each end of a push-pull pair transmission line, i.e., one pair of coupling capacitors between a transmitter and a conductor of the line, and another pair of coupling capacitors between that conductor and a receiver. In various embodiments, a conductor (or simply "cable") may be implemented in any suitable wiring scheme, e.g.,B. as a single conductor (i.e., a conductor wire), as a coaxial cable, or as a paired conductor such as an unshielded twisted pair (UTP) or shielded twisted pair (STP), depending on the transmission scheme used (i.e., depending on whether the transmission scheme is single-ended or push-pull). In some embodiments, the cable of a video transmission channel may be an RCA cable or a coaxial cable (having a signal wire that is at least partially enclosed in a shield of conductive material), or an unshielded AVSS, CIVUS, or similar signal wire within a shielded bundle.

[0031] Fig. 2 and Fig. Figure 3 shows schematic examples of a single-ended and a push-pull pair transmission channel.

[0032] In an AC-coupled transmission scheme 200, which is in Fig. As shown in Figure 2, a signal, which may include an analog-formatted video signal, is transmitted via a single-conductor cable 208, which can be considered a transmission channel 208. In some embodiments, the conductor cable 208 may have a simple conductive wire. In some embodiments, the conductor cable 208 may have a coaxial cable having a conductive core wire and a conductive shield, the core wire carrying the video signal and the shield being grounded. Since the transmission scheme 200 is a single-ended signaling transmission scheme, only a first wire carries a varying voltage between the transmitter and the receiver, while a second wire conductor (in Figure 200) carries the signal. Fig. 2 not shown) to a reference voltage signal (such as that provided by a Fig. 2 (shown ground reference 214 provided) can be connected and this can lead to this. As shown in Fig. As shown in Figure 2, the conductor cable 208 can connect a transmitter 202 and a receiver 216. In this scheme, one or more coupling capacitors 206a, 206b can be connected between the transmitter 202 and the receiver 216. Specifically, one or more coupling capacitors 206a can be connected between the transmitter 202 and the conductor cable 208, and one or more coupling capacitors 206b can be connected between the conductor cable 208 and the receiver 216. The transmitter 202 can have a total resistance 204, while the receiver 216 can have a total resistance 212, which are connected in series with the transmitter 202.

[0033] Alternatively, in an AC-coupled transmission scheme 300, which is in Fig. Figure 3 shows a signal, which may include an analog-formatted video signal, being transmitted over a differential-mode pair conductor cable 308, which can be considered a transmission channel 308. In some embodiments, the conductor cable 308 may comprise a UTP or an STP cable. Although a common-mode implementation may be advantageous due to its simpler implementation and lower cost, differential-mode pair signal transmission schemes can advantageously provide immunity to external EMI and reduce the amount of electromagnetic emissions generated by the link. This is because the characteristics of the two separate signals / lines of the differential-mode conductor pair can be selected to provide suppression of common-mode interference. As shown in Figure 3, the characteristics of the two separate signals / lines of the differential-mode conductor pair can be selected to provide suppression of common-mode interference signals. Fig. As shown in Figure 3, a transmitter 302, which may have resistors 304a and 304b (connected in series with the transmitter 302) in the two lines of the push-pull pair circuit, is connected to the conductor cable 308 via a pair of coupling capacitors 306a, 306b. Similarly, a receiver 316 is connected to the conductor cable 308 via a resistor 312 (connected in parallel with the receiver 316) and a pair of coupling capacitors 306c, 306d. Undesired effects of periodic interference signals

[0034] Sometimes, noise signals can undesirably interfere with an analog video signal transmitted from a transmitter to a receiver. In such cases, the analog video signal is said to be affected by such noise. In some deployment scenarios, the interference may take the form of one or more periodic noise signals, such as periodic EMI noise, which may be added to the transmitted video signal. A schematic representation of such a scenario is shown in Fig. 4 shown.

[0035] Fig. Figure 4 shows a video system 400 comprising a transmitter 410 and a receiver 420. The transmitter 420 is configured to send a video signal to the receiver 420 via a cable 408. In some embodiments, the transmitter 410, the receiver 420, and the cable 408 can be designated as the transmitter 202, the receiver 216, and the cable 208, respectively. Fig. 2 be implemented. In other embodiments, the transmitter 410, the receiver 420 and the cable 408 can be represented as the transmitter 302, the receiver 316 and the cable 208 respectively. Fig. 3 be implemented. In some embodiments, the transmitter 410, the receiver 420 and the cable 408 can be designated as the transmitter 910, the receiver 920 and the cable 930 respectively. Fig. 9 will be implemented.

[0036] As it is in Fig. As shown in Figure 4, the transmitter 410 can receive an input video signal, which can be referred to as the "Tx input" 412, and can generate an output video signal based on the Tx input 412, which can be referred to as the "Tx output" 414. The Tx output 414 is then transmitted from the transmitter 410 to the receiver 420 via the cable 408. During transmission, a periodic noise signal (or several periodic noise signals) can interfere and thereby affect the Tx output 414. Such a noise signal is shown in Fig. Figure 4 is shown with a sinusoidal noise signal 402, although in various embodiments of the present disclosure the noise signal 402 can be any periodic signal that can interfere with the Tx output 414 as described herein. As shown schematically in Fig. As shown in Figure 4, the noise signal 402 can be effectively added to or superimposed on the Tx output 414 by an adder 404. Consequently, an input video signal to the receiver 420, which can be referred to as the "Rx input" 422, contains a combination (e.g., a sum) of the Tx output 414 and the noise signal 402. The receiver 420 can be configured to process the Rx input 422 and generate an output video signal based on the Rx input 422. The Rx output 424 can then be rendered on a display.

[0037] The inventors of the present disclosure recognized that if the noise signal 402 is a periodic signal, adding such a signal to the Tx output 414 results in a certain phase difference of the noise signal from one video line to the next in the Rx input 422. The inventors further recognized that some ranges of values ​​of such a phase difference can cause the noise signal to be out of phase from one video line to another. In this case, the noise signal 402 can be spatially integrated by the human eye and will not be visible when the Rx output 424 is rendered on a display.On the other hand, some other values ​​of a phase difference from one video line to the next can cause the noise signal from one video line to the next to be in phase or strongly correlated, in which case the noise signal 402 may be clearly visible and may degrade the image quality when the Rx output 424 is rendered on a display.

[0038] For example, suppose that the video signal to be transmitted contains active video data, where each frame has 720 lines, each line has 1280 pixels, and the video line frequency is 45 kilohertz (kHz). Further, suppose that the video system 400 is subjected to a sinusoidal noise signal (audio) 402. Now, two different examples for different frequencies of the noise signal 402 are analyzed.

[0039] In a first example, the frequency of the 402 noise signal is 18 megahertz (MHz). In this case, the 402 noise signal has an integer number of cycles per video line, since 18 MHz / 45 kHz = 400. This can be considered a "perfect" correlation, where the phase of the 402 noise signal is identical from line to line. The 402 noise signal is superimposed on the video signal and appears as a static pattern of peaks and troughs on the image, which is visible to the eye and degrades image quality.

[0040] In a second example, the frequency of the noise signal 402 is 18.0225 MHz. In this case, the noise signal 402 has 400.5 cycles per video line (18.0225 MHz / 45 kHz = 400.5), and the noise signal 402 is phase-shifted by 180 degrees on alternating lines (i.e., the phase difference of the noise signal 402 from one line to the next will be 180 degrees). When displayed on a screen, due to the small distance between pixel lines on high-resolution displays, the grid-like appearance of the phase-shifted character is invisible to the human eye.

[0041] As the preceding description shows, the phase difference of a noise signal from one line to the next depends on the frequency of the noise signal (for a given video line frequency). The inventors of the present disclosure recognized that four cases or ranges of interest can be identified in the line-to-line phase difference of the noise signal. Case 1: The phase difference in the noise signal from one video line to the next is between 0 and 90 degrees. In this case, the noise is strongly correlated from line to line, clearly visible, and degrades the image quality. Case 2: The phase difference in the noise signal from one video line to the next is between 90 and 180 degrees. In this case, the noise is out of phase from line to line and is spatially integrated by the human eye (not visible). Case 3: The phase difference in the noise signal from one video line to the next is between 180 and 270 degrees.In this case, the noise is out of phase from line to line and is spatially integrated by the human eye (not visible). Case 4: The phase difference in the noise signal from one video line to the next is between 270 and 360 degrees. In this case, the noise is highly correlated from line to line, clearly visible, and degrades the image quality.

[0042] To address this problem, the inventors developed a technique that can be described as "video line inversion." This technique can reduce or eliminate the adverse effects of periodic noise signals that can interfere with the transmission of an analog video signal from a transmitter to a receiver. Video line inversion

[0043] Video line inversion is based on the understanding that if it could be ensured that the phase difference of the noise signal from line to line (i.e., on adjacent video lines) lies between 90 and 270 degrees (cases 2 and 3 as described above), the noise signal would be out of phase from line to line and invisible to the human eye. Video line inversion then aims to maximize the occurrence of the constellation in which, regardless of the frequency of a noise signal, the phase difference of the noise signal on adjacent video lines lies between 90 and 270 degrees.

[0044] In an illustration of an embodiment of video line inversion with reference to the video system 400 of Fig. In case 4, the first step can be for the receiver 420 to identify the presence of a noise signal and determine the line-to-line phase difference of the noise signal. If the phase difference is between 0 and 90 degrees or between 270 and 360 degrees (i.e., cases 1 and 4 described above), the receiver 420 can provide the transmitter 410 with a signal 406 indicating that a video line inversion is required. The transmitter 410 can then begin inverting the video on alternating lines. The receiver 410 can then detect this inversion and reverse the effect on the video data by performing a second inversion. However, since the noise signal 402 was added to the video signal during transmission, the first inversion (i.e., the inversion by the transmitter 410) is not applied to it.In this case, the second inversion in the receiver 420 inverts the phase of the noise signal 402, resulting in the phase difference of the noise signal 402 on adjacent video lines being between 0 and 90 degrees, or between 270 and 360 degrees, as it lies within the range of 90 to 270 degrees. In this way, the phase difference of the noise signal 402 between adjacent lines can be kept within the optimal range where it is not perceptible to the eye. Thus, if the receiver 420 determines that the phase difference of the noise signal 402 between adjacent video lines is as described in cases 1 and 4 above, the line inversion is activated, while if the receiver 420 determines that the phase difference of the noise signal 402 between adjacent video lines is as described in cases 2 and 3 above, the line inversion is deactivated.Various scenarios of phase differences in a noise signal from one video line to another, and a result of implementing a video line inversion as described herein, can be illustrated with reference to the representations of . Fig. 5-7 will be explained.

[0045] Fig. Figure 5 is a schematic representation 500 of a noise signal that is out of phase with video lines, according to some embodiments of the present disclosure. In particular, the representation 500 shows two adjacent video lines that are in Fig. 5 are designated as "Line N" and "Line N+1", where N is an integer specifying a particular video line (N) and the next video line (N+1). For each video line, Figure 500 shows the Tx input 412, the Tx output 414, the Rx input 422, and the Rx output 424, as described above. Figure 500 further shows the noise signal 402, shown as a dashed sinusoidal curve, superimposed on the Rx input 422 and the Rx output 424 for each of the lines N and N+1. A comparison of the noise signal 402 between the Rx input 422 for line N and the Rx input 422 for line N+1 (i.e., the one shown in Figure 500) is shown. Fig. Figure 5 (shown in a semicolon box 502) shows that the noise signal 402 in the Rx input 422 in line N+1 is phase-shifted by 180 degrees relative to the noise signal 402 in the Rx input 422 in line N. This is in the range of 90 to 270 degrees (i.e., in cases 2 and 3 described above), which means that the phase difference of the noise signal 402 between adjacent lines is already in the optimal range where it is not visible to the eye and where no inversion is required. Thus, line inversion is disabled in both the transmitter 410 and the receiver 420. The line inversion disabled in the transmitter 410 can be seen from Figure 500 by comparing the Tx input 412 and the Tx output 414 for line N+1 (i.e., the one shown in Figure 500). Fig. 5 in a semicolon box 504) can be observed, which shows that the video data of line N+1 is not inverted by the transmitter 410. The line inversion disabled in the receiver 420 can be seen from the representation 500 by comparing the Rx input 422 and the Rx output 424 for line N+1 (i.e., the one shown in Fig. 5 in a semicolon box 506 video lines) can be observed, which shows that the video data of line N+1 is not inverted by receiver 420.

[0046] Fig. Figure 6 is a schematic representation of a noise signal 600 that is in phase with video lines, according to some embodiments of the present disclosure. Similar to in Fig. Figure 5 shows the representation 600, the Tx input 412, the Tx output 414, the Rx input 422, and the Rx output 424 for two adjacent video lines N and N+1, as well as another example of the noise signal 402. A comparison of the noise signal 402 between the Rx input 422 for line N and the Rx input 422 for line N+1 (i.e., the one in Fig. Figure 6 (shown in a semicolon box, 602 video lines) shows that the noise signal 402 in the Rx input 422 in line N+1 is in phase (i.e., 0 degrees phase difference) with the noise signal 402 in the Rx input 422 in line N. This is within the range of 0 to 90 degrees (i.e., case 1 described above), which means that the noise is strongly correlated from line to line, clearly visible, and degrades the image quality. Thus, a line inversion for the noise in Figure 6 would be necessary. Fig. Scenario 6 shown is helpful, but is not yet activated. The line inversion deactivated in transmitter 410 can be seen in representation 600 by comparing the Tx input 412 and the Tx output 414 for line N+1 (i.e., the one shown in Fig. 6 in a semicolon box 604) can be observed, which shows that the video data of line N+1 is not inverted by the transmitter 410. The line inversion disabled in the receiver 420 can be seen from the representation 600 by comparing the Rx input 422 and the Rx output 424 for line N+1 (i.e., the video lines shown in 604), which shows that the video data of line N+1 is not inverted by the transmitter 410. Fig. 6 video lines shown in a semicolon box 606) can be observed, which shows that the video data of line N+1 is not inverted by the receiver 420. In this case, the Rx output 424 will show a visual degradation when rendered on a display due to the presence of the noise signal 402.

[0047] Fig. Figure 7 is a schematic representation 700 of a noise signal that is in phase with video lines and whose video inversion is implemented by a transmitter and a receiver, according to some embodiments of the present disclosure. Similar to in Fig. Figure 6 shows the representation 700, the Tx input 412, the Tx output 414, the Rx input 422 and the Rx output 424 for two adjacent video lines N and N+1. Fig. Figure 7 shows the same example of the noise signal 402 as the one in Fig. Figure 6 shows a comparison of the noise signal 402 between the Rx input 422 for line N and the Rx input 422 for line N+1 (i.e., the one shown in Figure 6). Fig. Figure 7 (shown in a semicolon box, 702 video lines) shows that the noise signal 402 in the Rx input 422 in line N+1 is in phase (i.e., 0 degrees phase difference) with the noise signal 402 in the Rx input 422 in line N. Again, this is within the range of 0 to 90 degrees (i.e., case 1 described above), which means that the noise is strongly correlated from line to line, clearly visible, and degrades the image quality. In contrast to Fig. 6 shows Fig. Seven signals are emitted when line inversion is enabled. The line inversion enabled in transmitter 410 can be derived from the Fig. by comparing the Tx input 412 and the Tx output 414 for line N+1 (i.e. the one in Fig. 7 in a semicolon box 704) can be observed, which shows that the video data of line N+1 is inverted by the transmitter 410 (i.e., the Tx output 414 for line N+1 is inverted with respect to the Tx input 412 for line N+1). The line inversion activated in the receiver 420 can be seen from representation 700 by comparing the Rx input 422 and the Rx output 424 for line N+1 (i.e., the in Fig. 7 in a semicolon box 706) can be observed, which shows that the video data of line N+1 is inverted by the receiver 420 (i.e., the Rx output 424 for line N+1 is inverted with respect to the Rx input 422 for line N+1). The inversion at the receiver 420 effectively adds 180 degrees to the line-to-line phase difference in the noise signal 402 in the Rx output 424 (i.e., the in Fig. 7 video lines shown in a semicolon box 708) compared to the line-to-line phase difference in the noise signal 402 in the Rx input 424 (i.e., the one shown in Fig. 7 video lines shown in a semicolon box 702). This means that the phase difference of the noise signal 402 between adjacent lines in the RX output 424 is 180 degrees instead of 0 degrees as in the RX input 422, thus bringing it into the optimal range between 90 and 270 degrees (i.e., cases 2 and 3 described above), so that the noise signal 402 in the RX output 424 is not visible to the eye when the RX output 424 is rendered on a display.

[0048] To summarize the concepts presented by the descriptions of Fig. As highlighted in Figures 5-7, when video line inversion is implemented in the video system 400, the receiver 420 can be configured to determine the phase difference for the noise signal 402 from one video line to another of the Rx input 422. If it is determined that the phase difference is such that the noise signal 402 degrades the image quality, the receiver 420 can be configured to provide the transmitter 410 with a command 406 to perform video line inversion on a specific subset of video lines of a video signal to be transmitted. The transmitter 410 can then be configured to perform video line inversion on a subset of video lines of the Tx input 412 to produce the Tx output 414, and the receiver can be configured to perform video line inversion on the corresponding subset of video lines from the Rx input 422 to produce the Rx output 424.The inversion on the receiver 420 side effectively cancels the inversion performed on the transmitter 410 side, so that the video content of the Rx output 424 corresponds to that of the Tx input 412. However, since the inversion on the receiver 420 side also inverts the periodic noise signal 402 added to the Tx output 414 during transmission from the transmitter 410 to the receiver 420, it affects the phase difference of the noise signal 402 from one video line to another, effectively adding a 180-degree phase shift to the noise signal 402. In other words, the inversion on the receiver 420 side inverts the periodic noise signal 402 of the Rx input 422 to produce the Rx output 424 with an inverted version of the noise signal 402.Such an inversion of the noise signal 402 makes it possible to shift the phase difference from line to line of the noise signal 402 from a range in which it can visibly degrade the image quality to a range in which it can be spatially integrated by the human eye and is not visible to the human eye. For example, if before the inversion the line-to-line phase difference of the noise signal 402 (i.e., the line-to-line phase difference of the noise signal 402 in the RX input 422) is between 0 and 90 degrees or between 270 and 360 degrees (i.e., cases 1 and 4 described above), then the inversion performed by the receiver 420 causes the line-to-line phase difference of the noise signal 402 (i.e., the line-to-line phase difference of the noise signal 402 in the Rx output 424) to be shifted to a value between 90 and 270 degrees (cases 2 and 3 described above).Thus, before inversion, the line-to-line phase difference of the noise signal 402 in the Rx input 422 can be such that it degrades the image quality when the Rx input 422 is rendered on a display. However, the inversion performed by the receiver 420 to generate the Rx output 424 based on the Rx input 422 shifts the line-to-line phase difference of the noise signal 402 in the Rx output 424 into a range where the noise signal is phase-shifted from one video line to another. In this case, the noise signal 402 in the Rx output 424 can be spatially integrated by the human eye and will not be visible when the Rx output 424 is rendered on a display.

[0049] Fig. Figure 8 shows a flowchart of an exemplary method 800 for operating a system, e.g., a video system, configured to implement video line inversion for a video signal transmitted over an analog video link, according to some embodiments of the present disclosure. Method 800 can be implemented using any video system in which a video signal is captured by a camera or otherwise generated on the transmitting side and transmitted in analog format over a wired link from a transmitter to a receiver for processing on the receiving side (i.e., by the receiver) and possibly displayed on a screen. Method 800 is described with reference to the disclosure in Fig. The video system 400 shown in Figure 4 is illustrated. In general, however, the method 800 can be implemented wholly or partially using any other suitable video system comprising a transmitter and a receiver configured to implement a video line inversion as described herein, for example, one shown in Figure 4. Fig. 9 video systems shown 900 and / or one in Fig. 10 data processing systems 1000 shown, which are described below.

[0050] Method 800 can begin with block 802, in which the receiver 420 receives a first section of a video signal transmitted by the transmitter 410 (i.e., the receiver 420 receives a first section of the Tx output 414 as Rx input 422) and determines a phase difference in a noise signal in the first and second video lines of the first section of the received video signal (i.e., in the first section of the Rx input 422). In general, the receiver 420 configured to determine the phase difference in block 802 can have any data processing system configured to process data from the signals received by the receiver 420. In some embodiments, the first and second video lines for which the receiver 420 determines the phase difference in block 802 can be consecutive video lines of the Rx input 422, e.g., B. consecutive video lines of a single frame of the Rx input 422.In other embodiments, the first and second video lines for which the receiver 420 n block 802 determines the phase difference can be non-consecutive video lines of the Rx input 422 and can be either video lines of a single video frame or video lines of two different video frames of the video signal. Although representations of . Fig. 5-7, which are described above, refer to the evaluation of phase differences between successive video lines. The analysis of any two video lines, including non-consecutive lines, of the Rx input 422, based on the relationship between the frequency of the noise signal 402 and the video line frequency, could be reduced / translated into the phase difference between the two successive video lines, as described above. Therefore, determining the phase difference for any two video lines of a received video signal in block 802 can allow a determination of whether the noise signal 402 is such that it causes a visible degradation of the image quality (i.e., cases 1 and 4 described above) or whether the noise signal 402 is such that it does not cause a visible degradation of the image quality (i.e., cases 2 and 3 described above).

[0051] Procedure 800 can then proceed to Block 804, in which the receiver 420, which has any data processing system configured to process data from the signals received by the receiver 420, can determine, based on the phase difference determined in Block 802, whether a line inversion is required. In general, if the phase difference determined in Block 802 is within a certain predefined range (which may be one of several such ranges), the line inversion may be required in the form of a modification of a second section of the video signal by inverting a subset of several video lines of the second section of the video signal, and the receiver 420 can evaluate this in Block 804.For example, as described above, a row inversion may be necessary if the phase difference between two consecutive rows is between 0 and 90 degrees or between 270 and 360 degrees (i.e., cases 1 and 4 described above). Conversely, a row inversion may not be necessary if the phase difference between two consecutive rows is between 90 and 270 degrees (i.e., cases 2 and 3 described above).This principle can be extended to the phase difference, which is determined for any first and second lines of the first section of the video signal, even if they are not consecutive lines, in order to define one or more phase difference ranges in which a line inversion is required, since otherwise the phase noise of the Rx output 424 is visible to the eye and degrades the image quality, and to define one or more phase difference ranges in which no line inversion is required, since without it the phase noise of the Rx output 424 is not visible to the eye.

[0052] If the receiver 420 determines in block 804 that a row inversion is required, the method 800 can proceed to block 806, in which the row inversion functionality is activated in both the receiver 420 and the sender 410. For this purpose, in some embodiments, the receiver 420 can provide the sender 410 with the instruction 406 to activate the row inversion functionality, or in other embodiments, the receiver 420 and / or the sender 410 can be manually configured to activate the row inversion functionality based on the decision of block 804.For the time being, when the line inversion functionality is enabled, transmitter 410 is configured to perform a line inversion for active pixel data for a specific subset of video lines of the video signal to be transmitted (Tx input 412), thereby producing the Tx output 414 with some video lines that are inverted compared to the Tx input 412, e.g., as in the example in Box 704 of . Fig. Figure 7 shows. Similarly, the receiver 420 is initially configured to perform the line inversion functionality for active pixel data for the same subset of video lines of the video signal received by the receiver 420 (Rx input 422) when the line inversion functionality is enabled, thereby producing the Rx output 424 with some inverted video lines compared to the Rx input 422, as shown in Fig. 8 with block 808 is shown, e.g. as in the example in box 706 of Fig. 7 shown.

[0053] If the receiver 420 determines in block 804 that no row inversion is required, the method 800 can proceed to block 810, in which the row inversion functionality is disabled in both the receiver 420 and the sender 410. For this purpose, in some embodiments, the receiver 420 can provide the sender 410 with the instruction 406 to disable the row inversion functionality, or in other embodiments, the receiver 420 and / or the sender 410 can be manually configured to disable the row inversion functionality based on the decision of block 804. For the time being, when the line inversion functionality is deactivated, transmitter 410 is configured not to perform line inversion for active pixel data for any video lines of the Tx input 412 of the video signal, thereby generating the Tx output 414 in which, compared to the Tx input 412, none of the video lines are inverted, e.g.as in the example in box 504 of . Fig. 5 shown. Similarly, when the line inversion functionality is disabled, the receiver 420 is initially configured not to perform line inversion for active pixel data for any video lines of the video signal received by the receiver 420 (the Rx input 422), thereby producing the Rx output 424 in which, compared to the Rx input 422, none of the video lines are inverted, as shown in Fig. 8 with block 812 is shown, as in the example in box 506 of Fig. 5 shown.

[0054] In some embodiments, the method 800 can be performed several times during the transmission of a video signal from the transmitter 410 to the receiver 420, which can advantageously enable the video system 400 to adapt to a potentially changing nature of the noise signal 402. As described above, the first and second sections of the video signal referred to in the method 800 each refer only to a section of a video signal on the basis of which the phase difference is determined and a decision is made to activate or deactivate the line inversion, and a section of a video signal for which the line inversion is activated and deactivated in the transmitter and in the receiver.

[0055] For example, in some embodiments, the receiver 420 can be configured to determine the phase difference as described with reference to block 802 and to make the decision regarding the activation or deactivation of the line inversion as described with reference to block 804 by evaluating the noise signal 402 in a section of an HBI for a first video line and evaluating the noise signal 402 in a section of an HBI for a second video line. Thus, in such embodiments, the phase difference in block 802 is determined as a phase difference between the noise signal 402 in an HBI (“first HBI”) of a first video line of the Rx input 422 and the noise signal 402 in an HBI (“second HBI”) of a second video line of the Rx input 422.In some such embodiments, the first HBI and the second HBI can be the HBIs assigned to two consecutive video lines of a single video frame of the first section of the video signal. In other embodiments, the first HBI and the second HBI can be the HBIs assigned to two non-consecutive video lines of a single video frame of the first section of the video signal. In still other embodiments, the first HBI and the second HBI can be the HBIs assigned to video lines of two different frames. In each of these embodiments, the first and second HBI can be assigned to the first and second video lines for which the phase difference is determined, but this need not be the case.Thus, the noise signal for the first and second HBIs, which are associated with any two video lines of the first section of the video signal, can be compared, but the result of the comparison can be used to deduce the phase difference between any other two video lines of the first section of the video signal. In some embodiments of such an example, the section of the first HBI for which the noise signal is evaluated may be a front blanking shoulder, a rear blanking shoulder, or a horizontal synchronization pulse of the first HBI. Similarly, the section of the second HBI for which the noise signal is evaluated may be a front blanking shoulder, a rear blanking shoulder, or a horizontal synchronization pulse of the second HBI.

[0056] In another example, in some embodiments, the phase difference in block 802 can be determined by comparing the noise signal in a first line of a vertical blanking interval (VBI) of the first section of the video signal and the noise signal in a second line of the VBI (i.e., the same VBI). In some embodiments, the first and second lines of the VBI in which the noise signal is compared can be two consecutive lines of the VBI. In other embodiments, the first and second lines of the VBI in which the noise signal is compared can be two non-consecutive lines of the VBI. Again, in each of these embodiments, the first and second lines of the VBI can, but need not, correspond to the first and second video lines for which the phase difference is determined.Thus, the noise signal for the first and second lines of a VBI can be compared, which are associated with two specific frames of the first section of the video signal, but the result of the comparison can be used to derive the phase difference between two video lines in one or more frames of the first section of the video signal.

[0057] In another example, in some embodiments the phase difference in block 802 can be determined by comparing the noise signal in a section of a first VBI of the video signal and the noise signal in a section of a second VBI of the video signal (i.e. in different VBIs).

[0058] As the examples above illustrate, in some embodiments, the determination of the phase difference in a noise signal in the first and second video lines in block 802 can be accomplished by determining the phase difference in other parts of the video signal, rather than in the active pixel data of the first and second video lines themselves, for example, in HBIs associated with the first and second video lines, or in one or more VBIs. This can be advantageous because such parts of the video signal may be partially predictable (e.g.,The front blanking shoulder, rear blanking shoulder, and horizontal synchronization of an HBI should each be at a specific predefined level or have a specific predefined waveform, whereas the active pixel data of video lines themselves may not be, and therefore identifying a periodic noise signal in the video lines themselves may be considerably more difficult or even impossible. Once a phase difference is determined from such parts of a video signal, a phase difference between the first and second video lines can be derived. In other embodiments, block 802 may include determining the phase difference by evaluating the noise signal in the first and second video lines themselves, e.g., when the transmitter 410 is configured to send specific test video lines to the receiver 420.Video lines with certain known active pixel contents that would allow the receiver 420 to isolate the noise signal 402 and determine the phase difference in the Rx input 422 from the first to the second video line.

[0059] Block 804 of Procedure 800 may include the receiver 420 determining that line inversion is required if the phase difference determined in Block 802 is such that it corresponds to a phase difference between two consecutive video lines of the Rx input 422 of the received video signal between 0 and 90 degrees or between 270 and 360 degrees (e.g., the phase difference between two consecutive video lines of the Rx input 422 of the received video signal is between approximately -90 degrees and +90 degrees). If it is determined that line inversion is required, the subset of the multiple video lines to be inverted by the transmitter 410 and the receiver 420 may include every second video line (e.g., every second video line, i.e., all odd video lines or all even video lines) of the multiple video lines of the video signal.

[0060] It should also be noted that the phase difference determination in block 802 can also be performed when the transmitter 410 and the receiver 420 are already performing line inversion (i.e., what is referred to as the "second section" of the video signal in the description of method 800 can also serve as the "first section" in the subsequent execution of block 802). In such a case, the receiver 420 can adjust the phase difference ranges to determine whether to retain or disable line inversion in block 804. In some embodiments, the transmitter 410 can be configured to provide the receiver 420 with an indication of whether to enable or disable line inversion in the transmitter 410 to generate the Tx output 414 sent to the receiver 420.For example, in some embodiments, the transmitter 410 can be configured to indicate / identify the configuration of the current frame in a corresponding test line sent to the receiver 420 as part of the video signal. In another example, such a test line can be applicable to multiple frames of the video signal. The receiver 420 can then be configured to extract the transmitter configuration from this information (e.g., from the test line) and to enable or disable line inversion according to the information supplied by the transmitter 410, i.e., to enable line inversion if the transmitter 410 performs line inversion, and to disable line inversion if the transmitter 410 does not perform line inversion. For example, in some embodiments, a test line can be transmitted by the transmitter 410 during the inactive region in the transmitter 410 (i.e.,(if no active pixel data is transmitted) and can be, for example, a full amplitude to indicate to receiver 420 that row inversion is enabled, and an amplitude of 0 to indicate to receiver 420 that row inversion is disabled, or vice versa.

[0061] In some embodiments, the measurement of block 802 and / or the decision 804 is performed multiple times over several different sections of the received video signal, and then the final decision to enable or disable line inversion is made. Such embodiments can lead to improved accuracy of the decision.

[0062] Although this is not specifically in Fig. As shown in Figure 8, the method 800 can further include reproducing the Rx output 424 of the received signal once the corresponding line inversion has been performed. This can, for example, involve displaying the received video on a screen. Exemplary video system

[0063] Fig. Figure 9 shows an exemplary video system 900 according to some embodiments of the present disclosure. As it is described in Fig. As shown in Figure 9, the exemplary system 900 can have a transmitter 910 and a receiver 920 coupled by an analog connection 930. The analog connection 930 can be any suitable wired conductor cable, such as the single-ended conductor cable 208 or the push-pull pair cable 308, which are described above with reference to AC-coupled connections. In other examples, the analog connection 930 can be an analog DC-coupled connection. The transmitter 910 can be the transmitter 410 and / or the receiver 920 can be the receiver 420, as described above.

[0064] As it is in Fig. As shown in Figure 9, the transmitter 910 can include a video signal generator 912 or be communicatively coupled to it. The video signal generator 912 can include any suitable means for generating a signal to be transmitted to the receiver 920 via the analog connection 930. In some embodiments, the video signal generator 912 can, for example, include any suitable image sensor, image system processor, or any suitable camera (which may contain multiple cameras) configured to capture a video signal (which may contain multiple video signals). In other embodiments, the signal generator 912 can include means for generating a computer-generated video signal.

[0065] What happens next in Fig. As shown in Figure 9, the transmitter 910 may also include one or more digital-to-analog converters (DACs) 914 or be communicatively coupled to them. As used herein, the term "DAC" refers to an electronic circuit / device that converts a digital value, representing the amplitude of a continuous physical quantity, into a corresponding analog value. In some embodiments, the one or more DACs 914 may be configured to receive a digital video signal containing digital pixel values ​​and convert the digital values ​​(i.e., values ​​discrete in time and in the amplitude of the digital signal) into an analog signal with continuous time and amplitude. In some embodiments, the one or more DACs 914 may be configured to receive a digital signal generated by the signal generator 912, e.g.,to convert a digital video signal containing digital pixel values, as captured by a camera (e.g., when line inversion is disabled). In other embodiments, the one or more DACs 914 can be configured to convert a processed version of the digital signal generated by the signal generator 912, which, for example, has been processed by the transmitter logic 916 to contain certain subsets of invertible video lines, as described here (e.g., when line inversion is enabled). Thus, the one or more DACs 914 convert digitally processed signals into the analog domain for analog transmission to the receiver 920 via the analog connection 930.

[0066] In some embodiments, the transmitter 910 may include one or more analog-to-digital converters (ADCs) in addition to the one or more DACs 914 (in Fig. 9 not specifically shown). As used herein, the term “ADC” refers to an electronic circuit / device that converts a continuous physical quantity, carried by an analog signal, into a digital number representing the amplitude of the quantity (or into a digital signal carrying that digital number). The result is a sequence of digital values ​​(i.e., a digital signal) by which an analog input signal of continuous time and continuous amplitude is converted into a digital signal of discrete time and discrete amplitude. Various converters contained in the Transmitter 910 can operate by being supplied with clock signals from a clock generator (in Fig. 9 not specifically shown), e.g. under the control of processor 915, are generated.

[0067] As in Fig. As shown in Figure 9, the transmitter 910 may furthermore include the transmitter logic 916 or be communicatively coupled to it. The transmitter logic 916 may be implemented in hardware, software, firmware, or any suitable combination of one or more of these and may be configured to control the operation of the transmitter 910 as described herein. For this purpose, the transmitter logic 916 may use at least one processor 915 and at least one memory element 917 together with any other suitable hardware and / or software to enable its intended functionality, namely to use phase difference measurements on the noise signal to implement line inversion of certain video lines of a video signal to be transmitted over the analog link 930, as described herein.In some embodiments, the processor 915 can execute software or an algorithm to perform the activities discussed in this disclosure. For example, the processor 915 can execute the algorithms that control the digital-to-analog conversion of signals generated by the signal generator 912 for transmission over the analog transmission link 930. Furthermore, the processor 915 can execute algorithms that control the generation and transmission of the Tx output 414 to the receiver 920, as described herein. For this purpose, the processor 915 can be configured to receive pixel values ​​of the signal generated by the signal generator 912, for example, in the digital form as generated by the signal generator 912 and prior to conversion to analog signals by the DAC 914, and to perform an inversion of several pixel values ​​for some video lines when line inversion is enabled as described herein.Thus, in some embodiments, the processor 915 can perform a line inversion of several pixel values ​​for selected video lines in the digital domain before the digital signal with inverted video lines is converted to the analog domain for transmission to the receiver 920. The processor 915 can also be configured to control the transmission of the Tx output 414 of the analog signal to the receiver 920, as described herein. Further descriptions of the processor 915 and the memory element 917 are given below.

[0068] It is also in Fig. Figure 9 shows that the transmitter 910 can also include a signal transmission circuit arrangement 918 for sending signals to the receiver 920 or be communicatively coupled to it. In particular, the signal transmission circuit arrangement 918 can include components for enabling analog transmission of the analog video signal, such as that received by the DAC 914 and processed by the transmitter logic 916. In some embodiments, such components can include coupling capacitors, e.g., coupling capacitors on the transmitter side, as described with reference to Fig. 2 and Fig. 3, as well as any other circuit known in the prior art used for the analog transmission of signals. In addition, the signal transmission circuit arrangement 918 may further comprise components for enabling the transmission from the transmitter 910 to the receiver 920 of an indication that the transmitter 910 is activated to perform a line inversion as described herein. In various embodiments, such an indication may be transmitted either as part of the video signal (i.e., contained therein) to be transmitted in analog format over the connection 930, or via a separate communication channel between the transmitter 910 and the receiver 920, the separate communication channel being either wired or wireless.

[0069] Referring to the receiving side of the Video System 900, as described in Fig. As shown in Figure 9, the receiver 920 can include a signal reception circuit arrangement 928, a receiver logic 926, an ADC 924, and optionally a video consumption device 922, or be communicatively coupled to it. In some embodiments, the video consumption device 922 can be a video processing device such as an image system processor, a video analysis device such as an ADAS processor, or a video rendering device such as a display.

[0070] The signal receiving circuit arrangement 928 can be configured to receive signals from the transmitter 910. In particular, the signal receiving circuit arrangement 928 can include components for enabling the reception of an AC- or DC-coupled transmission of the analog video signal, which is to be provided, for example, to the ADC 924 for conversion to the digital domain and for further processing by the receiver logic 926, possibly after conversion by the ADC 924. In some embodiments, components for enabling the reception of an AC- or DC-coupled transmission of the analog video signal can include coupling capacitors, e.g., coupling capacitors on the receiver side as described with reference to Fig. 2 and Fig. 3, as well as any other circuit known in the prior art that is to be used for receiving analog signals. Furthermore, the signal receiving circuit arrangement 928 may also include components for enabling the reception of other information from the transmitter 910. As described herein, in various embodiments, such other information, e.g., an indication of whether the transmitter 910 is enabled to implement line inversion, may be transmitted either as part of (i.e., contained within) the video signal to be transmitted in analog format over the analog link 930, or via a separate communication channel between the transmitter 910 and the receiver 920, the separate communication channel being either wired or wireless.

[0071] As it is in Fig. As shown in Figure 9, the receiver 920 can also include one or more ADCs 924. In the case of the ADC 924 used in the video system 900, the analog input signal to be converted can be the video signal transmitted by the transmitter 910 via the analog video link 930 and received by the signal receiving circuit arrangement 928, e.g., to be further processed in digital form by the receiver logic 926. In some embodiments, the receiver 920 can also include one or more DACs (in Figure 9). Fig. 9 not specifically shown). Various converters contained in the receiver 920 can operate by being supplied with clock signals, which, e.g. under the control of the processor 925, are generated by a clock generator (in Fig. 9 not specifically shown) are generated.

[0072] Similar to the transmitter logic 916, the receiver logic 926 can be implemented in hardware, software, firmware, or any suitable combination of one or more of these and can be configured to control the operation of the receiver 920 as described herein. For this purpose, the receiver logic 926 can use at least one processor 925 and at least one memory element 927, together with any other suitable hardware and / or software, to enable its intended functionality of determining the phase difference between the noise signal in the first and second video lines and using the determined phase difference to determine, as described herein, whether to enable or disable line inversion. In some embodiments, the processor 925 can execute software or an algorithm to perform the activities discussed herein.For example, the processor 925 can execute the algorithms that control the analog-to-digital conversion of signals received by the signal receiving circuit arrangement 928 after they have been transmitted over the analog transmission link 930, possibly after they have been converted to the digital domain by the ADC 924. The processor 925 can further execute algorithms that control the determination of the phase difference between the noise signal in the first and second video lines and use the determined phase difference to determine whether to enable or disable line inversion as described herein. The processor 925 can also be configured to indicate to the transmitter 910, as described herein, whether to enable or disable line inversion.When the line inversion described herein is enabled, the processor 925 can further be configured to receive pixel values ​​of the signal received from the transmitter 910, e.g., in the digital form converted by the one or more ADCs 924, and to perform an inversion of several pixel values ​​for some video lines. Thus, in some embodiments, the processor 925 can perform a line inversion of several pixel values ​​for selected video lines in the digital domain after the analog signal with inverted video lines has been received from the transmitter 910 and converted into the digital domain. Further descriptions of the processor 925 and the memory element 927 are given below.

[0073] The 915 and 925 processors can each be configured to communicate with other system elements via one or more connections or buses. Such a processor can include any combination of hardware, software, or firmware providing programmable logic, including a microprocessor, a digital signal processor (DSP), a field-programmable gate array (FPGA), a programmable logic array (PLA), an application-specific integrated circuit (ASIC), or a virtual machine processor. The 915 processor can be communicatively coupled with the 917 memory element, while the 925 processor can be communicatively coupled with the 927 memory element, for example, in a direct memory access (DMA) configuration.Memory elements 917 and 927 may each incorporate any suitable volatile or non-volatile memory technology, including double data rate random access memory (DDR), synchronous RAM (SRAM), dynamic RAM (DRAM), flash memory, read-only memory (ROM), optical media, virtual memory areas, magnetic or tape storage, or any other suitable technology. Unless otherwise specified, each of the memory elements discussed herein should be designed to fall under the general term "memory element."

[0074] The information tracked or sent to the one or more components or elements of Sender 910 and Receiver 920 could be provided and / or stored in any database, register, control list, cache, or memory structure, all of which could be referenced at any appropriate time. Such memory options may be included in the general term "memory element" used herein and may be used to implement Memory Element 917 and / or Memory Element 927. Similarly, each of the potential processing elements, modules, and machines described herein should be designed to be included in the general term "processor" used herein and may be used to implement Processor 915 and / or Processor 925. Each of the in Fig. The 9 elements shown, e.g., the signal generator 912, the DAC 914, the transmitter logic 916, the video consumption 922, the ADC 924 or the receiver logic 926, may also include suitable interfaces for receiving, sending and / or otherwise transmitting data or information in a network environment, either via a wired or wireless communication link.

[0075] In certain example implementations, mechanisms for using video line inversion to reduce the influence of periodic interference on the analog transmission of video signals, as described herein, can be implemented by logic encoded in one or more physical media, which may include non-volatile media, e.g., embedded logic provided in an ASIC, in DSP instructions, software (possibly including object code and source code) to be executed by a processor or other similar machine, etc. In some of these cases, memory elements, such as those in Fig. The memory elements 917 and 927 shown in Figure 9 store data or information used for the operations described here. This includes the possibility that the memory elements can store software, logic, code, or processor instructions that are executed to perform the activities described here. A processor can execute any type of instruction associated with the data or information to achieve the operations described here. For example, the processors, such as those shown in Figure 9, could store data or information used for the operations described here. Fig. The processors 915 and 925 shown in Figure 9 transform an element or object (e.g., data) from one state or thing to another state or thing. In another example, the activities described herein can be implemented with fixed logic or programmable logic (e.g., software / computer instructions executed by a processor), and the elements identified herein could be some type of programmable processor, programmable digital logic (e.g., an FPGA, a DSP, an erasable programmable read-only memory, an electrically erasable programmable read-only memory), or an ASIC comprising digital logic, software, code, electronic instructions, or a suitable combination thereof. Exemplary data processing system

[0076] Fig. Figure 10 provides a block diagram illustrating an exemplary data processing system for using video line inversion to reduce the influence of periodic interference signals on the analog transmission of video signals, as disclosed herein, according to some embodiments of the present disclosure. Such a data processing system could be configured to implement various improved mechanisms relating to the video line inversion disclosed herein, for example, functioning as the transmitter logic 916 and / or receiver logic 926 described herein, or as any other system configured for this purpose.

[0077] As it is in Fig. As shown in Figure 10, the data processing system 1000 can have at least one processor 1002, which is coupled to memory elements 1004 via a system bus 1006. Therefore, the data processing system can store program code in memory elements 1004. Furthermore, the processor 1002 can execute the program code that is accessed from the memory elements 1004 via a system bus 1006. In one aspect, the data processing system can be implemented as a computer capable of storing and / or executing program code. However, it is understood that the data processing system 1000 can be implemented in the form of any system that has a processor and memory and is capable of performing the functions described in this disclosure.

[0078] In some embodiments, the processor 1002 can be the processor 915 and the memory elements 1004 can be the memory elements 917 of the transmitter 910 of the in Fig. The video system 900 shown in Figure 9 is as described above. In some embodiments, the processor 1002 may be the processor 925, and the memory elements 1004 may be the memory elements 927 of the receiver 920 of the system shown in Figure 9. Fig. 9 Videosystem 900 shown, as described above.

[0079] The memory elements 1004 can include one or more physical storage devices, such as local memory 1008 and one or more mass storage devices 1010. Local memory can refer to RAM or other non-persistent storage devices, which are generally used during the actual execution of the program code. A mass storage device can be implemented as a hard disk or other persistent data storage device. The processing system 1000 can also include one or more cache memories (not shown) that provide temporary storage of at least a portion of the program code to reduce the frequency with which program code needs to be retrieved from the mass storage device 1010 during execution.

[0080] Input / output devices (I / O devices), depicted as input device 1012 and output device 1014, can optionally be connected to the data processing system. Examples of input devices include, but are not limited to, a keyboard, a pointing device such as a mouse, or the like. Examples of output devices include, but are not limited to, a monitor or display, speakers, or the like. Input and / or output devices can be connected to the data processing system either directly or via intermediary I / O controllers.

[0081] In one embodiment, the input and output devices can be implemented as a combined input / output device (in Fig. Figure 10 (shown with a dashed line surrounding the input device 1012 and the output device 1014). An example of such a combined device is a touch-sensitive display, sometimes called a "touchscreen display" or simply a "touchscreen". In such an embodiment, input to the device can be provided by moving a physical object, such as a pen or a user's finger, on or near the touchscreen display.

[0082] When used in a video system according to various embodiments of the present disclosure, e.g. in the one described in Fig. In the video system 900 shown in Figure 9, the input device 1012 can be used to receive an input, such as that supplied by a user, and to configure the video system 900 according to the user input. For example, the input received by the input device 1012 can configure the transmitter 910 and / or the receiver 920 to enable or disable the video line inversion, e.g., based on the phase difference determination performed in Block 802 of Method 800.

[0083] Optionally, a network adapter 1016 can also be connected to the data processing system to enable it to connect to other systems, computer systems, remote network devices, and / or remote storage devices via intervening private or public networks. The network adapter can include a data receiver for receiving data sent from the systems, devices, and / or networks to the data processing system 1000, and a data transmitter for sending data from the data processing system 1000 to the systems, devices, and / or networks. Modems, cable modems, and Ethernet cards are examples of different types of network adapters that can be used with the data processing system 1000.

[0084] When used in a video system according to various embodiments of the present disclosure, e.g. in the one described in Fig. In the video system 900 shown in Figure 9, the network adapter 1016 can be used to receive input from other systems, computer systems, remote network devices, and / or remote storage devices via intervening private or public networks and to configure the video system 900 according to the received input. For example, the network adapter 1016 can be configured to receive input examples as described with reference to the input received by the user through the input device 1012, except that they are now received from other systems, computer systems, remote network devices, and / or remote storage devices via intervening private or public networks. The transmitter 910 and the receiver 920 of the video system 900 can then be configured according to the input received by the network adapter 1016, e.g.,configured to enable or disable video line inversion as described herein.

[0085] As it is in Fig. As shown in Figure 10, the storage elements 1004 can store an application 1018. In various embodiments, the application 1018 can be stored in the local memory 1008, in one or more mass storage devices 1010, or separately from the local memory and the mass storage devices. It is understood that the data processing system 1000 also includes an operating system (in Fig. (10 not shown) can execute, which can facilitate the execution of application 1018. Application 1018, implemented in the form of executable program code, can be executed by the data processing system 1000, for example, by processor 1002. In response to the execution of the application, the data processing system 1000 can be configured to perform one or more of the operations or procedural steps described herein. Selected examples

[0086] Example 1 provides a video system for transmitting video signals in analog form over a video link (e.g., implemented as a wired connection). The system includes a receiver configured to: receive a first segment of a video signal sent by a transmitter over the video link; determine a phase difference between a noise signal in a first video line of the first segment of the video signal and the noise signal in a second video line of the first segment of the video signal; and then, if it is determined that the phase difference is within a predefined range, modify a second segment of the video signal received by the receiver by inverting a subset of several video lines of the second segment of the video signal.

[0087] Example 2 provides the video system according to Example 1, wherein the first video line and the second video line are consecutive lines that are assigned to a single frame of the first section of the video signal.

[0088] Example 3 provides the video system according to Example 1, wherein the first video line and the second video line are non-consecutive lines that are assigned to a single frame of the first section of the video signal.

[0089] Example 4 provides the video system according to Example 1, where the first video line and the second video line are video lines that are assigned to different frames of the first section of the video signal.

[0090] Example 5 provides the video system according to one of Examples 1 to 4, wherein the phase difference is determined by comparing the noise signal in a section of a first HBI of the first section of the video signal and the noise signal in a section of a second HBI of the first section of the video signal.

[0091] Example 6 provides the video system according to Example 5, wherein the section of the first HBI is a front blanking shoulder, a rear blanking shoulder or a horizontal synchronization pulse of the first HBI and the section of the second HBI is a front blanking shoulder, a rear blanking shoulder or a horizontal synchronization pulse of the second HBI.

[0092] Example 7 provides the video system according to one of Examples 1 to 4, where the phase difference is determined by comparing the noise signal in a first line of a VBI and the noise signal in a second line of the VBI (i.e., the same VBI).

[0093] Example 8 provides the video system according to one of Examples 1 to 4, wherein the phase difference is determined by comparing the noise signal in a section of a first VBI of the first section of the video signal and the noise signal in a section of a second VBI of the first section of the video signal.

[0094] Example 9 provides the video system according to one of the preceding examples, where the phase difference is within the predefined range if any amount of the phase difference is less than approximately 90 degrees (i.e., if the phase difference is approximately between -90 degrees and +90 degrees, or in other words, if the phase difference is either between 0 and 90 degrees or between 270 and 360 degrees).

[0095] Example 10 provides the video system according to one of the preceding examples, wherein the subset of the multiple video lines of the second section of the video signal contains every second video line (e.g., every second video line, i.e., all odd video lines or all even video lines) of the multiple video lines of the second section of the video signal.

[0096] Example 11 provides the video system according to one of the preceding examples, wherein, when it is determined that the phase difference is within the predefined range, the transmitter is configured to activate a video line inversion, in which the transmitter inverts the subset of the multiple video lines of the second section of the video signal.

[0097] Example 12 provides the video system according to Example 11, wherein the receiver is further configured to provide the sender with a signal to activate video line inversion when it is determined that the phase difference is within the predefined range, and the sender is configured to activate video line inversion in response to receiving the signal from the receiver.

[0098] Example 13 provides the video system according to Example 11, with the transmitter trained by manual configuration to enable video line inversion.

[0099] Example 14 provides the video system according to one of Examples 11-13, wherein the receiver is further configured to receive a signal indicating whether video line inversion is enabled (i.e., applied) in the sender. In some embodiments, the signal can be provided by the sender. In other embodiments, the signal can be received from another entity, such as user input, if the receiver is manually configured to perform video line inversion because video line inversion is enabled in the sender.

[0100] Example 15 provides the video system according to one of the preceding examples, where the video link is an AC-coupled video link.

[0101] Example 16 provides a video system for transmitting video signals in analog form over a wired connection (i.e., via a wired video link). The system includes a transmitter configured to: generate a transmit output video signal (Tx output) based on a transmit input video signal (Tx input) by inverting a subset of several video lines of the Tx input; provide an indication to a receiver that the subset of several video lines is inverted; and transmit the Tx output in analog form over the wired link to the receiver.

[0102] Example 17 provides the video system according to Example 16, which further comprises the receiver, wherein the receiver is configured to: receive a receive input video signal (Rx input), wherein the Rx input specifies the Tx output (e.g., is based on it or contains it); receive the indication that the subset of the multiple video lines in the Tx output is inverted; and generate a receive output video signal (Rx output) based on the Rx input by inverting the subset of the multiple video lines of the Rx input.

[0103] Example 18 provides the video system according to Example 17, wherein the receiver is further configured to: determine, prior to generating the Tx output by inverting the subset of the multiple video lines of the Tx input, that a noise signal added to the Tx output during transmission from the sender to the receiver would result in visible degradation, and provide a signal to the sender to generate the Tx output by inverting the subset of the multiple video lines of the Tx input.

[0104] Example 19 provides a video system for transmitting video signals in analog form over a video link (e.g., implemented as a wired connection). The system includes a receiver and a transmitter. The transmitter is configured to send a video signal (Tx output) in analog format to the receiver over a wired connection. The receiver is configured to receive the video signal (Rx input) sent by the transmitter. If the video signal (Rx input) received by the receiver contains a periodic noise signal (in addition to the video signal data sent by the transmitter), and the periodic noise signal is such that a line-to-line phase difference of the periodic noise signal in the video signal (Rx input) received by the receiver lies within a predefined range, then both the transmitter and the receiver are configured to activate line inversion.When line inversion is enabled in the transmitter, the transmitter is configured to invert a subset of multiple video lines of the video signal before the video signal is sent to the receiver. Similarly, when line inversion is enabled in the receiver, the receiver is configured to invert a subset of multiple video lines of the video signal received, for example, before the received video signal is displayed on a screen. Therefore, if a line-to-line phase difference of the periodic noise signal in the video signal received by the receiver is within a predefined range, both the transmitter and the receiver are configured to enable line inversion for a subset of multiple video lines of the video signal.

[0105] Example 20 provides the video system according to Example 19, where the predefined range is between -90 degrees and +90 degrees (i.e., when the amount of the line-to-line phase difference is less than about 90 degrees, or, in other words, when the line-to-line phase difference is either between 0 and 90 degrees or between 270 and 360 degrees).

[0106] Example 21 provides the video system according to Examples 19 or 20, wherein the subset of the multiple video lines of the video signal contains every second line (e.g., all odd video lines or all even video lines) of active pixel values ​​of at least one section of the video signal.

[0107] Example 22 provides the video system according to one of Examples 19 to 21, wherein the receiver is configured to determine the line-to-line phase difference of the periodic noise signal in the video signal received by the receiver, and is further configured to provide a notification to the transmitter when it is determined that the line-to-line phase difference of the periodic noise signal in the video signal received by the receiver is within the predefined range.

[0108] Example 23 provides the video system according to one of Examples 19 to 22, wherein the sender is configured to provide the receiver with an indication that line inversion is enabled in the sender if the sender inverts the subset of the multiple video lines of the video signal before sending the video signal to the receiver.

[0109] Example 24 provides a method for operating a video system for transmitting video signals in analog format over a video link. The method comprises a transmitter of a video system sending a first section of a video signal to a receiver of the video system; and further comprises the receiver determining a phase difference between a noise signal in a first video line of the first section of the video signal received from the transmitter and the noise signal in a second video line of the first section of the video signal received from the transmitter. If it is determined that the phase difference is within the predefined range, the method comprises the receiver providing the transmitter with a signal to modify a second section of the video signal by inverting a subset of several video lines of the second section of the video signal before transmission to the receiver.If it is determined that the phase difference lies within the predefined range, the method further comprises the transmitter sending the second section of the video signal to the receiver, with the subset of the multiple video lines of the second section of the video signal inverted, and the receiver inverting the subset of the multiple video lines of the second section of the video signal received from the transmitter to generate a modified second section of the video signal. Optionally, the method also comprises the receiver displaying the modified second section of the video signal on a display.

[0110] Example 25 provides the procedure according to Example 24, which further includes the sender sending a statement to the receiver that the sender is modifying the second section of the video signal by inverting the subset of the multiple video lines of the second section of the video signal.

[0111] Example 26 provides the procedure according to Examples 24 to 25, which is trained to work with or in the video system according to one of the preceding examples.

[0112] Example 27 provides a method for operating the video system according to one of the preceding examples.

[0113] The system, transmitter, receiver, and method of any of the preceding examples can each be implemented in a vehicle or in a surveillance system. Furthermore, the system, transmitter, receiver, and method of any of the preceding examples can each include a camera or be communicatively coupled to a camera configured to capture the video signal to be transmitted via an analog transmission link, e.g., an AC-coupled link, wherein the camera can have multiple optical sensors (e.g., photodiodes) configured to generate pixel values ​​of the video signal to be transmitted over the link. Other remarks, variations and applications for implementation

[0114] The principles and advantages discussed here can be used in any device or system in which video or image data is transmitted over an analog transmission link and in which one or more periodic noise signals can interfere with the transmission. It is understood that not all of the goals or advantages mentioned herein can necessarily be achieved according to any particular embodiment described herein. For example, those skilled in the art will recognize that certain embodiments may be designed to operate in a manner that achieves or optimizes one advantage or group of advantages as taught herein, without necessarily achieving other goals or advantages as may be taught or suggested herein.

[0115] In an exemplary embodiment, any number of electrical circuits of the figures can be implemented on a circuit board of an associated electronic device. The circuit board can be a general-purpose printed circuit board that can accommodate various components of the electronic device's internal electronic system and also provide connections for other peripheral devices. In particular, the circuit board can provide the electrical connections through which the other components of the system can communicate electrically. Any suitable processors (including DSPs, microprocessors, supporting chipsets, etc.), computer-readable non-volatile memory elements, etc., can be appropriately coupled to the circuit board based on specific configuration requirements, processing requirements, computer designs, etc.Other components, such as external memory, additional sensors, audio / video display controllers, and peripherals, can be connected as plug-in cards, wired to the board, or integrated into the board itself. In various embodiments, the functions described herein can be implemented in emulation form as software or firmware running in one or more configurable (e.g., programmable) elements arranged in a structure that supports these functions. The software or firmware providing the emulation can be provided on non-volatile, computer-readable storage media containing instructions that enable a processor to execute these functions.

[0116] In another exemplary embodiment, the electrical circuits of the figures can be implemented as independent modules (e.g., a device with associated components and circuits configured to perform a specific application or function) or as plug-in modules in application-specific hardware of electronic devices. It should be noted that certain embodiments of the present disclosure can readily be contained, either partially or completely, in a system-on-a-chip (SOC) assembly. An SOC is an integrated circuit (IC) that integrates components of a computer or other electronic system onto a single chip. It can include digital, analog, mixed-signal, and often high-frequency functions, all of which can be provided on a single chip substrate.Other embodiments may include a multi-chip module (MCM) with several separate ICs arranged in a single electronic assembly and configured to interact closely with each other via the electronic assembly. In various other embodiments, the digital filters may be implemented in one or more silicon cores in application-specific integrated circuits (ASICs), FPGAs, and other semiconductor chips.

[0117] It is also essential to note that all specifications, dimensions, and relationships described herein (e.g., the number of processors, logic operations, etc.) are provided for illustrative and teaching purposes only. Such information may be substantially modified without deviating from the intent of the present disclosure or the scope of the appended claims. The specifications apply only to a non-limiting example and should be interpreted accordingly. Exemplary embodiments have been described in the preceding description with reference to specific arrangements of components. Various modifications and alterations may be made to such embodiments without deviating from the scope of the appended claims. The description and drawings should therefore be considered illustrative rather than limiting.

[0118] It should be noted that in the numerous examples provided here, the interaction may be described in terms of two, three, four, or more electrical components. This has been done, however, only for the sake of clarity and illustrative purposes. It is understood that the system can be distributed or combined in any suitable way. Along similar design alternatives, any of the components, modules, and elements of the figures can be combined in various possible configurations, all of which are clearly within the broad scope of this disclosure. In certain cases, it may be simpler to describe one or more of the functions of a particular set of processes by referring only to a limited number of electrical elements.It is understood that the electrical circuits shown in the figures and their teachings are readily scalable and can accommodate a large number of components as well as more intricate / complex arrangements and configurations. Accordingly, the examples provided should not limit the scope or hinder the general teachings of electrical circuits as they may be applied to a wide variety of other architectures.

[0119] It should be noted that in the present disclosure, references to various features (e.g., elements, structures, modules, components, steps, operations, properties, etc.) that appear in "one embodiment," "an exemplary embodiment," "another embodiment," "some embodiments," "different embodiments," "other embodiments," "alternative embodiments," and the like, are intended to mean that such features are included in one or more embodiments of the present disclosure, but need not necessarily be combined in the same embodiments.

[0120] It is also important to note that the functions relating to video line inversion for reducing the influence of periodic interference signals on the analog transmission of video signals, e.g., those found in one or more of the Fig. The processes shown in the figures are summarized below, illustrating only some of the possible functions that can be performed by or within the systems depicted in the figures, e.g., those shown in Fig. 4, Fig. 9 or Fig. The systems shown in section 10 can be performed. Some of these operations may be deleted or removed, or these operations may be substantially modified or altered without deviating from the scope of this disclosure. In addition, the timing of these operations may be substantially changed. The preceding operational sequences, as described, for example, in Fig. Figure 8 is shown for illustrative and discussion purposes. Significant flexibility is provided by the embodiments described herein insofar as all suitable arrangements, chronologies, configurations, and timing mechanisms can be provided without deviating from the teachings of the present disclosure.

[0121] Numerous other changes, substitutions, variations, modifications, and alterations may be recognized by those skilled in the art, and it is intended that the present disclosure encompasses all such changes, substitutions, variations, modifications, and alterations that fall within the scope of the appended claims. It should be noted that all optional features of any of the devices, apparatus, or systems described above may also be implemented with respect to the method or processes for using or operating the devices, apparatus, or systems, and the details given in the examples for devices, apparatus, or systems described herein may be used anywhere in corresponding methods or processes, and vice versa.

[0122] According to one aspect, systems and procedures are provided that use video line inversion to reduce the influence of periodic interference signals on the analog transmission of video signals over wired links. Under certain circumstances, a transmitter can be configured to perform video line inversion for a specific subset of video lines of a video signal before the video signal is sent to the receiver, and a receiver can be configured to perform a corresponding inversion for the same subset of video lines of the video signal received at the receiver.Such video line inversion performed by the sender and receiver can advantageously reduce or eliminate the effects of periodic interference signals that might affect the video signal during transmission, resulting in improved video quality rendered on the receiver side.

Claims

[1] Video system (900) featuring: a signal receiving circuit arrangement (928) designed to: Receiving a first section and a second section of a video signal (906) transmitted by a transmitter (910) over a video link; and a receiver logic (926) trained to: Determining a phase difference between a noise signal (908) in a first video line (102) of the first section of the video signal (906) and the noise signal (908) in a second video line (102) of the first section of the video signal (906); when it is determined that the phase difference is within a predefined range, providing a signal to the transmitter (910) to generate the second section of the video signal (906) by inverting a subset of several video lines (102) of a transmit input video signal (412); Modifying the second section of the video signal (906) received by the signal receiving circuit arrangement (928) by inverting that subset of the multiple video lines (102) of the transmit input video signal (412) which was inverted by the transmitter (910) to generate the second section of the video signal (906). [2] Video system (900) according to claim 1, wherein the first video line (102) and the second video line (102) are consecutive lines which are assigned to a single frame of the first section of the video signal (906). [3] Video system (900) according to claim 1, wherein the first video line (102) and the second video line (102) are non-consecutive lines that are assigned to a single frame of the first section of the video signal (906). [4] Video system (900) according to claim 1, wherein the first video line (102) and the second video line (102) are video lines (102) that are assigned to different individual frames of the first section of the video signal (906). [5] Video system (900) according to any one of claims 1 to 4, wherein the phase difference is determined by comparing the noise signal (908) in a section of a first horizontal blanking interval, hereinafter HBI, of the first section of the video signal (906) and the noise signal (908) in a section of a second HBI of the first section of the video signal (906). [6] Video system (900) according to claim 5, wherein: the section of the first HBI is an anterior blanking shoulder (106), a posterior blanking shoulder (108) or a horizontal synchronization pulse (100) of the first HBI and the section of the second HBI is an anterior blanking shoulder (106), a posterior blanking shoulder (108) or a horizontal synchronization pulse (100) of the second HBI. [7] Video system (900) according to any one of claims 1 to 6, wherein the phase difference is within the predefined range when an amount of the phase difference is less than 90 degrees. [8] Video system (900) according to any one of claims 1 to 7, wherein the subset of the multiple video lines (102) of the second section of the video signal (906) includes every second video line (102) of the multiple video lines (102) of the second section of the video signal (906). [9] Video system (900) according to any one of claims 1 to 8, wherein when it is determined that the phase difference is within the predefined range, the transmitter (910) is configured to activate a video line inversion, in which the transmitter (910) inverts the subset of the multiple video lines (102) of the second section of the video signal (906). [10] Video system (900) according to claim 9, wherein the transmitter (910) is configured by manual configuration to activate video line inversion. [11] Video system (900) according to claim 9 or 10, wherein the receiver logic (926) is further configured to receive a signal indicating whether the video line inversion is enabled in the transmitter (910). [12] Video system (400) comprising a transmitter (910): a transmitter logic (916) trained to: Generating a transmit output video signal, hereinafter referred to as Tx output (414), based on a transmit input video signal, hereinafter referred to as Tx input (412), by inverting a subset of several video lines (102) of the Tx input (412), wherein the Tx output (414) is generated in response to a receiver (420) determining that a noise signal (402) added to the Tx output (414) during transmission from the transmitter (410) to the receiver (420) would result in visible degradation, and to the transmitter (410) receiving from the receiver (420) an instruction to generate the Tx output (414) by inverting the subset of several video lines (102) of the Tx input (412); and Providing information to the receiver (420) that the subset of multiple video lines (102) is inverted; and a signal transmission circuit arrangement (918) designed to: Sending the Tx output (414) in analog form via a wired connection to the receiver (420). [13] Video system (400) according to claim 12, further comprising the receiver (420), wherein the receiver (420) comprises: a signal receiving circuit arrangement (928) designed to: Receiving a receive input video signal, hereinafter referred to as Rx input (422), wherein the Rx input (422) specifies the Tx output (414); and a receiver logic (926) configured to: Receiving the information that the subset of multiple video lines (102) is inverted in the Tx output (414); and Generating a receive output video signal, hereinafter Rx output (424), based on the Rx input (422) by inverting the subset of the multiple video lines (102) of the Rx input (422). [14] Video system (400) according to claim 12, wherein the receiver (420) is further configured to: Determine that the noise signal (402) added to the Tx output (414) during transmission from the transmitter (410) to the receiver (420) would result in a visible degradation by determining that a phase difference between the noise signal (402) in a first video line (102) and the noise signal (402) in a second video line (102) of the Tx output (414) received by the receiver (420) is within a predefined range. [15] Video system (400) according to claim 14, wherein the phase difference is within the predefined range when an amount of the phase difference is less than 90 degrees. [16] Video system (400) for transmitting video signals (906) in analog form via a video connection, wherein the video system (400) comprises: a recipient; and a transmitter (410), where: the transmitter (410) has a signal transmission circuit arrangement (918) configured to transmit a first section and a second section of a video signal (906) to the receiver (420); the receiver (420) has a signal receiving circuit arrangement (928) configured to receive the first section and the second section of the video signal (906) transmitted by the transmitter (410), the receiver (420) furthermore has a receiver logic (926) which is configured to: Determining a line-to-line phase difference of a periodic noise signal (402) in the first section of the video signal (906) received by the signal receiving circuit arrangement (928), if the line-to-line phase difference is within a predefined range, providing a signal to the transmitter (410) to generate the second section of the video signal (906) by inverting a subset of several video lines (102) of a transmit input video signal before the second section of the video signal (906) is transmitted to the receiver (420), and inverting the subset of several video lines (102) of the second section of the video signal (906) received by the signal receiving circuit arrangement (928). [17] Video system (400) according to claim 16, wherein the predefined range is between -90 degrees and +90 degrees. [18] Video system (400) according to claim 16 or 17, wherein the subset of the multiple video lines (102) of the video signal (906) has every second line of active pixel values ​​of the second section of the video signal. [19] Video system (400) according to one of claims 16 to 18, wherein the transmitter (410) is configured to provide the receiver (420) with an indication that a line inversion is activated in the transmitter (410) when the transmitter (410) inverts the subset of the multiple video lines (102) for generating the second section of the video signal (906) before sending the second section of the video signal (906) to the receiver (420). [20] Video system (400) according to any one of claims 16 to 19, wherein the line-to-line phase difference is within the predefined range when an amount of the line-to-line phase difference is less than 90 degrees.

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