Image information difference calculation circuit based on slope switching technology and vision sensor

Abstract

The application provides an image information difference calculation circuit based on a slope switching technology and a visual sensor, and the circuit comprises a difference unit configured to perform time difference and / or space difference calculation on two pixel signals of an image to obtain an image pixel difference signal; and a switching unit configured to switch a slope signal according to the image pixel difference signal. The application can greatly improve the perception ability of the visual sensor to the space-time dynamic information, and realizes high-precision, high-frame-rate, high-dynamic-range and high-efficiency robust visual representation.

Description

Technical Field

[0001] This invention relates to the field of image processing technology, and in particular to an image information differential calculation circuit and a vision sensor based on ramp switching technology. Background Technology

[0002] A vision sensor is a photoelectric detection device used to sense visible light information in the environment and convert it into an electrical signal. Various types of vision sensors have been developed, such as CMOS image sensors (CIS) and dynamic vision sensors (DVS), to provide high-performance image information of objects. DVS is characterized by its ability to sense changes in dynamic scenes in the form of a sparse event stream. It has a fast shooting speed and a large dynamic range of acquired image signals. However, this type of sensor suffers from low resolution and excessive loss of effective information. Summary of the Invention

[0003] This invention provides an image information differential calculation circuit and a vision sensor based on ramp switching technology. It designs a circuit that simultaneously calculates high-precision temporal and spatial differentials at the column level. Furthermore, using column-level differential calculation can significantly reduce pixel size, achieving pixel miniaturization. This invention enables image sensing with simultaneous high dynamic range, high speed, high resolution, and wide spectral response.

[0004] This invention provides an image information differential calculation circuit based on ramp switching technology, comprising: a differential unit for performing temporal and / or spatial differential calculations on two pixel signals of an image to obtain an image pixel differential signal; and a switching unit for switching a ramp signal according to the image pixel differential signal.

[0005] According to an image information differential calculation circuit provided by the present invention, the pixel signal of the image includes a first pixel value and a second pixel value; the switching unit includes: a comparator, used to switch to an ascending ramp signal when the second pixel value is greater than the first pixel value; or, to switch to a descending ramp signal when the second pixel value is less than the first pixel value.

[0006] According to the present invention, an image information differential calculation circuit based on ramp switching technology is provided. The first input terminal of the comparator is electrically connected to the output terminal of the differential unit, and the second input terminal of the comparator is used to input a rising ramp signal or a falling ramp signal. The comparator is also used to detect the difference between the image pixel differential signal and the ramp signal. The circuit further includes a counter, the input terminal of which is electrically connected to the output terminal of the comparator, for counting according to the difference, so as to quantize the image pixel differential signal into the counter's count data.

[0007] According to the present invention, an image information differential calculation circuit based on ramp switching technology is provided, wherein the comparator is used to: output a first level when the image pixel difference signal is greater than the ramp signal; or output a second level when the image pixel difference signal is less than the ramp signal; the first level and the second level are opposite levels.

[0008] According to the present invention, an image information differential calculation circuit based on ramp switching technology is provided, wherein the first level is a high level and the second level is a low level; the counter is used to: start counting when receiving a high level from the comparator; and stop counting when receiving a low level from the comparator.

[0009] According to the present invention, an image information differential calculation circuit based on ramp switching technology further includes: a readout unit, wherein the input terminal of the readout unit is electrically connected to the output terminal of the pixel unit, and is used to read out the pixel signal of the image using a column-level signal readout method; and a storage unit, wherein the input terminal of the storage unit is electrically connected to the output terminal of the readout unit, and the output terminal of the storage unit is electrically connected to the input terminal of the differential unit, and is used to store the pixel signal of the image.

[0010] According to the present invention, an image information differential calculation circuit based on ramp switching technology is provided, wherein the image pixel differential signal is a temporal differential signal and / or a spatial differential signal; the temporal differential signal is the differential signal between signals of pixels in the same range at two sampling times; and the spatial differential signal is the differential signal between signals of pixels in two ranges at a given distance at the same sampling time.

[0011] According to the present invention, an image information differential calculation circuit based on ramp switching technology is provided, wherein the range pixels include multiple pixel units within the fusion range; the pixel signal of the image is the result of fusing the signals of the multiple pixel units within the fusion range into a single output signal.

[0012] The present invention also provides a vision sensor, including a pixel array and the aforementioned image information differential calculation circuit based on ramp switching technology; the image information differential calculation circuit is disposed at the output end of the pixel array; the pixel array includes multiple pixel units.

[0013] The present invention also provides a terminal including the aforementioned visual sensor.

[0014] This invention provides an image information differential calculation circuit and a vision sensor based on ramp switching technology, which can significantly improve the vision sensor's ability to perceive spatiotemporal dynamic information and achieve high-precision, high-frame-rate, high-dynamic-range, and efficient and robust visual representation. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of an image information differential calculation circuit based on ramp switching technology provided by the present invention.

[0017] Figure 2 This is a schematic diagram of the specific structure of an image information differential calculation circuit based on ramp switching technology provided by the present invention. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0019] An event camera, also known as a dynamic vision sensor (DVS), is a novel imaging system. Unlike traditional cameras that use shutter speed to control frame rate and record light intensity frame by frame, event cameras are sensitive to the rate of change in light intensity. Each pixel independently records the logarithmic change in light intensity at that pixel, generating a positive or negative pulse when the change exceeds a threshold. This asynchronous nature of event cameras allows them to operate without shutter speed limitations, resulting in extremely high temporal resolution (approximately 1,000,000 frames per second, compared to approximately 100 frames per second for traditional cameras). Combined with their sensitivity to change, this makes them naturally suited for tasks such as motion detection.

[0020] Because DVS pixels have a logarithmic response, they have a naturally high dynamic range, but are extremely susceptible to interference.

[0021] Event cameras have the following drawbacks: they can only detect changes over time; they can only detect low-precision changes of 1-bit; and their pixel size is too large to achieve high resolution.

[0022] This invention designs a circuit that simultaneously calculates high-precision temporal and spatial differential at the column level, overcoming the shortcomings of low precision and inability to detect spatial changes in event cameras. Furthermore, using column-level differential calculations can significantly reduce pixel size, enabling pixel miniaturization.

[0023] Please refer to Figure 1 , Figure 1 This is a schematic diagram of an image information differential calculation circuit based on ramp switching technology provided by the present invention.

[0024] This invention provides an image information differential calculation circuit based on ramp switching technology, comprising: a differential unit 1, used to perform temporal and / or spatial differential calculations on two pixel signals of an image to obtain an image pixel differential signal; and a switching unit 2, used to switch the ramp signal according to the image pixel differential signal.

[0025] In a preferred embodiment, the image pixel difference signal is a temporal difference signal and / or a spatial difference signal; the temporal difference signal is the difference signal between the signals of two sampling times of pixels in the same range; the spatial difference signal is the difference signal between the signals of two range pixels at a given distance in the same sampling time.

[0026] In a preferred embodiment, the pixel signal of the image includes a first pixel value and a second pixel value; the switching unit 2 includes a comparator, used to switch to an ascending ramp signal when the second pixel value is greater than the first pixel value; or, to switch to a descending ramp signal when the second pixel value is less than the first pixel value.

[0027] In a preferred embodiment, the first input terminal of the comparator is electrically connected to the output terminal of the differential unit 1, and the second input terminal of the comparator is used to input a rising ramp signal or a falling ramp signal; the comparator is also used to detect the difference between the image pixel difference signal and the ramp signal; the circuit also includes a counter, the input terminal of which is electrically connected to the output terminal of the comparator, for counting according to the difference, so as to quantize the image pixel difference signal into counter count data.

[0028] This invention provides an image information differential calculation circuit, including a differential unit 1 and a switching unit 2. When operating in time differential mode, the differential unit 1 reads the signal value V of the same pixel at two sampling times (t1 and t2) from the storage unit. SIG1 and V SIG2 It performs differential operations to generate a time-difference signal. When operating in spatial differential mode, differential unit 1 samples two pixel signals (e.g., V) at a specified distance from each other at the same sampling time. SIG(x,y) With V SIG(x+n,y)The signal is sampled and differentially divided to generate a spatial differential signal. The differential result is output to switching unit 2 in the form of an analog voltage. Switching unit 2 includes a comparator.

[0029] The comparator has two input terminals. The first input terminal is used to input the image pixel difference signal output by the difference unit 1, and the second input terminal is used to input the preset ramp signal (threshold) V. RAMP The comparator is used to detect the difference between the image pixel difference signal and the preset ramp signal. For example, the comparator determines V... SIG1 -V SIG2 The relationship between the absolute value and the threshold (preset ramp signal) is considered. If the value is less than the threshold, the comparator is turned off, and the counter clock is shut down to save power. Ultimately, the circuit output is 0.

[0030] The counter and comparator outputs are directly electrically connected, employing a synchronous binary counting architecture. The counter counts based on the difference, quantizing the image pixel difference signal into counter count data. At the start of the quantization cycle, the counter is reset to its initial value, and the counter increments each clock cycle. Ultimately, V can be obtained. SIG2 -V SIG1 The quantized value and sign are determined by a threshold.

[0031] In this embodiment, based on the first pixel value V SIG1 Second pixel value V SIG2 The slope direction is adaptively switched based on the size relationship: Ascending slope condition: when V SIG2 >V SIG1 When the slope selection switch is activated, it will switch the preset slope signal to the rising slope signal.

[0032] Descending slope condition: when V SIG2 <V SIG1 At this time, the slope selection switch will switch the preset slope signal to the descending slope signal.

[0033] This invention effectively improves the frame rate and pixel data processing efficiency of visual sensors while ensuring image clarity, meeting the requirements of high-speed photography. At the same time, by reducing the amount of output pixel data, it reduces the storage resource occupation of digital signals and the area of ​​memory units, and reduces the amount of processing and computation of digital signals corresponding to pixel data, thereby better adapting to the development trend of chip miniaturization.

[0034] As a preferred embodiment, it further includes: a readout unit, the input of which is electrically connected to the output of the pixel unit, for reading out the pixel signal of the image using a column-level signal readout method; and a storage unit, the input of which is electrically connected to the output of the readout unit, and the output of which is electrically connected to the input of the differential unit 1, for storing the pixel signal of the image.

[0035] In this embodiment, the readout unit reads the pixel signal of the image. The pixel signal of the image may include the pixel reset voltage and the pixel exposure voltage, and outputs the pixel signal of the image to the corresponding storage unit.

[0036] The storage unit stores the pixel signals of the image output by the readout unit. The storage unit adopts a dual-capacitor architecture with a first storage capacitor and a second storage capacitor to store pixel signals at different sampling times or different spatial locations.

[0037] The storage unit is also equipped with a ping-pong buffer mechanism. Each differential calculation is configured with two sets of storage capacitors. While one set of storage capacitors performs read and differential operations, the other set of storage capacitors performs sampling and writing, realizing uninterrupted continuous differential processing.

[0038] In a preferred embodiment, the comparator is configured to: output a first level when the image pixel difference signal is greater than the ramp signal; or output a second level when the image pixel difference signal is less than the ramp signal; the first level and the second level are opposite levels.

[0039] In this embodiment, the image pixel difference signal is input to the first input terminal (e.g., the negative input terminal) of the comparator, and the preset ramp signal is input to the second input terminal (e.g., the positive input terminal) of the comparator. The comparator compares the image pixel difference signal and the preset ramp signal, and outputs a corresponding signal to the counter according to the difference. The output signal of the comparator can characterize the difference between the image pixel difference signal and the preset ramp signal. For example, when the image pixel difference signal is greater than the preset ramp signal, the comparator outputs a first level (e.g., a high level signal), and when the image pixel difference signal is less than the preset ramp signal, the comparator outputs a second level (e.g., a low level signal).

[0040] The first and second levels are complementary level pairs with opposite logic, ensuring that the subsequent counter can reliably detect the quantization completion time.

[0041] In a preferred embodiment, the first level is a high level and the second level is a low level; the counter is used to: start counting when a high level is received from the comparator; and stop counting when a low level is received from the comparator.

[0042] In this embodiment, the enable terminal of the counter is directly electrically connected to the output terminal of the comparator. The counter can count according to the output signal of the comparator and is configured in a high-level active counting mode. Counting Start: When the counter receives a high level from the comparator output, the internal counting enable signal EN is activated. The counter increments on each rising edge of the counting clock CLK, and the count value N increases linearly from 0. During the duration of the high level, the counter maintains continuous counting.

[0043] Counting Stop: When the counter receives a low level from the comparator output, the internal counting enable signal EN is set to invalid, the counter immediately stops counting, and the current count value N is latched into the output register. The low level also triggers the counting completion flag signal.

[0044] The counter's output signal can be represented as a pulse signal, and the number of pulses can be used to represent the count value. This quantizes the image pixel difference signal into counter count data, obtaining the count data corresponding to each pixel. The quantized data includes the count data. The final output count result can be stored in a latch. Then, the pixel signal of the next specified pixel is read out, differentially processed, and quantized.

[0045] Please refer to Figure 2 , Figure 2 This is a schematic diagram of the specific structure of an image information differential calculation circuit based on ramp switching technology provided by the present invention.

[0046] As a preferred embodiment, the structure of the image information differential calculation circuit of the present invention is as follows: Readout Unit Section: The output terminal of the pixel unit is electrically connected to the first terminal of the current source Is, the first terminal of the first switch S1, and the first terminal of the third switch S3, respectively. The second terminal of the current source Is is grounded. The second terminal of the first switch S1 is electrically connected to the first terminal of the first capacitor C1. The second terminal of the first capacitor C1 is electrically connected to the negative input terminal of the operational amplifier A1, the first terminal of the capacitor Cf, and the first terminal of the second switch S2, respectively. The positive input terminal of the operational amplifier A1 receives the Vref signal. The enable terminal EN of the operational amplifier A1 is connected. The second terminal of the second switch S2 is electrically connected to the second terminal of the capacitor Cf, the output terminal of the operational amplifier A1, the first terminal of the switch SH1, and the first terminal of the switch SH2, respectively.

[0047] Storage unit and differential unit 1: The second terminal of switch SH1 is electrically connected to the first terminal of the second capacitor C2 and the first terminal of the first buffer U1 respectively. The second terminal of the second capacitor C2 is grounded. The second terminal of switch SH2 is electrically connected to the first terminal of the third capacitor C3 and the first terminal of the second buffer U2 respectively. The second terminal of the third capacitor C3 is grounded. The second terminal of the first buffer U1 is electrically connected to the first terminal of switch ST1. The second terminal of the second buffer U2 is electrically connected to the first terminal of switch ST2. The control signal of switch ST1 is ST1_PRE. The control signal of switch ST2 is ST2_PRE. The second terminal of switch ST1 is electrically connected to the second terminal of switch ST2, the second terminal of the third switch S3 and the first terminal of the fourth capacitor C4 respectively.

[0048] Comparator and Counter Section: The second terminal of the fourth capacitor C4 is electrically connected to the negative input terminal of comparator A2 and the first terminal of switch SC1, respectively. The first terminal of the fifth capacitor C5 is connected to the VRAMP signal, and the second terminal of the fifth capacitor C5 is electrically connected to the positive input terminal of comparator A2 and the first terminal of switch SC2, respectively. The second terminal of switch SC1 is connected to the Vref2 signal, and the second terminal of switch SC2 is connected to the Vref3 signal. The output terminal of comparator A2 is used to connect the threshold logic and the counter.

[0049] It should be noted that the circuit diagram V RAMP In the waveforms below, the black waveform represents the preset ramp signal V. RAMP The red waveform represents an image pixel difference signal greater than the preset ramp signal, while the purple waveform represents an image pixel difference signal less than the preset ramp signal. Both the red and purple waveforms fluctuate up and down; an upward-sloping waveform represents V. SIG2 >V SIG1 Then the preset ramp signal V RAMP Switch to an ascending ramp. A downward waveform represents V. SIG2 <V SIG1 Then the preset ramp signal V RAMP Switch to an ascending ramp.

[0050] In a preferred embodiment, the range of pixels includes multiple pixel units within the fusion range; the pixel signal of the image is the result of fusing the signals of the multiple pixel units within the fusion range into a single output signal.

[0051] Fusion technology is used to combine signals from multiple pixel units within a fusion pixel range into a single signal before outputting it. This invention supports temporal and spatial differential sensing, enabling larger receptive fields, larger spatial scales, and higher sensitivity through fusion technology. The operation of fusing multiple adjacent pixel output values ​​by sharing readout switches and storage nodes typically includes fusion of 2×2 pixel units, fusion of 3×3 pixel units, and other ranges. The fused pixels are combined into a large fused pixel output. The output value can be the sum of all fused pixel output values, the average value, or alternatively, the median, maximum, minimum value, or other functional relationships.

[0052] The fusion process can be performed in the charge domain, analog domain, or digital domain. Pixel fusion reduces the amount of data that needs to be processed / transmitted, and in some cases, it can improve the frame rate. Furthermore, the signal-to-noise ratio of the fused pixels is improved.

[0053] This invention introduces pixel fusion technology into the visual sensing chip architecture, which can improve the output signal-to-noise ratio and reduce the amount of data transmitted to alleviate bandwidth pressure.

[0054] The visual sensor provided by the present invention is described below. The visual sensor described below and the image information differential calculation circuit described above can be referred to in correspondence.

[0055] The present invention also provides a vision sensor, including a pixel array and the aforementioned image information differential calculation circuit; the image information differential calculation circuit is disposed at the output end of the pixel array; the pixel array includes multiple pixel units.

[0056] A vision sensor consists of a pixel array, which is composed of multiple pixels arranged in an array. For example, the pixel array includes multiple rows and columns of pixels. That is, any frame of image captured by the vision sensor is composed of multiple pixels arranged in an array.

[0057] In a preferred embodiment, each pixel unit in the pixel array is provided with a pulse generating module; or, all pixel units in the pixel array are connected to a common pulse generating module; or, the pixel array is divided into multiple ranges, and all pixel units in each range are connected to a common pulse generating module; wherein, the pulse generating module is used to generate a trigger signal at a fixed time interval, or at an adaptive, programmable variable time interval, to control the start exposure time and exposure duration of the photosensitive module, and pixel units connected to the same pulse generating module are exposed synchronously, and pixel units connected to different pulse generating modules are exposed synchronously or asynchronously; the photosensitive module is disposed within the pixel unit and is used to convert the light signal at the current pixel unit position into an analog electrical signal.

[0058] In this embodiment, the visual sensing chip integrates a trigger pulse generator to generate a trigger signal that controls the exposure of the photosensitive module, thereby accurately determining the signal acquisition time. The trigger pulse generator can be configured flexibly: if each pixel unit is configured with an independent trigger pulse generator, a full-array asynchronous exposure mode can be achieved. Each pixel unit adaptively adjusts the calculated trigger time of the spatiotemporal differential signal based on its perceived light intensity level, allowing each pixel unit to output information independently at any time, significantly improving system flexibility and reducing output latency; this mode can also be switched to full-array synchronous exposure as needed. If multiple pixel units share the same trigger pulse generator, these pixel units perform synchronous exposure.

[0059] The signal generation modes of the trigger pulse generator include fixed time interval triggering and adaptive or programmable variable interval triggering. When all pixel units in the array share a single trigger pulse generator, the entire array is in synchronous exposure mode, and the output of each pixel unit must follow a uniform timing pattern.

[0060] As a preferred embodiment, the exposure mode of each unit pixel in the pixel array is either global exposure or rolling exposure.

[0061] This embodiment supports multiple exposure modes, including Global Shutter and Rolling Shutter, to meet the needs of different application scenarios.

[0062] In global exposure mode, all pixel units within the array begin and end exposure simultaneously, ensuring that the acquired image is free from motion distortion, making it suitable for capturing high-speed moving targets. This mode can be achieved by controlling the synchronization of the entire array through a single trigger pulse generator, or by having each pixel unit's independent trigger pulse generator trigger collaboratively.

[0063] In rolling exposure mode, each pixel row or group is exposed sequentially, with the exposure time advancing row by row along the array. This mode has a simple circuit implementation, low power consumption, and is suitable for static or low-speed scenarios. By combining the adaptive characteristics of the trigger pulse generator, row-level asynchronous exposure can also be achieved, where each row of pixels is triggered independently based on its own light intensity conditions, balancing image quality and energy efficiency optimization.

[0064] In addition, this embodiment supports dynamic switching between two modes: global exposure is enabled in high-speed motion detection scenarios to ensure image integrity, while rolling exposure is switched in regular monitoring scenarios to reduce power consumption, thereby improving the environmental adaptability and energy efficiency of the visual sensing chip.

[0065] The terminal provided by the present invention will be described below. The terminal described below can be referred to in correspondence with the visual sensor described above.

[0066] The present invention also provides a terminal including the aforementioned visual sensor.

[0067] The present invention also provides a terminal device that integrates the above-mentioned visual sensor, which can be widely used in fields such as smartphones, tablets, wearable devices, drones, autonomous vehicles, bionic robots, security monitoring systems and industrial inspection devices to achieve high-speed, high-precision and low-latency visual information acquisition and processing.

[0068] The image information differential calculation method based on ramp switching technology provided by the present invention is described below. The image information differential calculation method based on ramp switching technology described below can be referred to in correspondence with the image information differential calculation circuit based on ramp switching technology described above.

[0069] This invention also provides a method for calculating image information difference based on ramp switching technology, comprising: The image pixel difference signal is obtained by performing time difference and / or spatial difference calculation on the two pixel signals of the image through the difference unit 1. The ramp signal is switched by switching unit 2 according to the image pixel difference signal.

[0070] In a preferred embodiment, the pixel signal of the image includes a first pixel value and a second pixel value; it also includes: switching to an ascending ramp signal via a comparator if the second pixel value is greater than the first pixel value; or, If the second pixel value is less than the first pixel value, switch to the downslope signal.

[0071] In a preferred embodiment, a rising ramp signal or a falling ramp signal is input via a comparator; the difference between the image pixel difference signal and the ramp signal is detected by the comparator. The image pixel difference signal is quantized into counter count data by counting the differences based on the differences.

[0072] As a preferred embodiment, the method further includes: when the image pixel difference signal is greater than the ramp signal, the comparator outputs a first level; or, When the image pixel difference signal is less than the ramp signal, the comparator outputs a second level; the first level and the second level are opposite levels.

[0073] In a preferred embodiment, the first level is a high level and the second level is a low level; it also includes: the counter starts counting when a high level is received from the comparator; The counter stops counting when it receives a low level from the comparator.

[0074] As a preferred embodiment, it also includes: The pixel signals of the image are read out using the column-level signal readout method through the readout unit; The pixel signals of the image are stored in the storage unit.

[0075] In a preferred embodiment, the image pixel difference signal is a temporal difference signal and / or a spatial difference signal; the temporal difference signal is the difference signal between the signals of two sampling times of pixels in the same range; the spatial difference signal is the difference signal between the signals of two range pixels at a given distance in the same sampling time.

[0076] In a preferred embodiment, the range of pixels includes multiple pixel units within the fusion range; the pixel signal of the image is an output signal that fuses the signals of the multiple pixel units within the fusion range into one.

[0077] The present invention also provides an electronic device, which may include: a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus 804. The processor can call logical instructions in the memory to execute an image information differential calculation method based on ramp switching technology. The method includes: performing temporal and / or spatial differential calculations on two pixel signals of an image through a differential unit 1 to obtain an image pixel differential signal; and switching a ramp signal according to the image pixel differential signal through a switching unit 2.

[0078] Furthermore, the logical instructions in the aforementioned memory can be implemented as software functional units and sold or used as independent products, and can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0079] On the other hand, the present invention also provides a computer program product, which includes a computer program that can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the image information differential calculation method based on ramp switching technology provided by the above methods. The method includes: performing temporal and / or spatial differential calculations on two pixel signals of an image through a differential unit 1 to obtain an image pixel differential signal; and switching a ramp signal according to the image pixel differential signal through a switching unit 2.

[0080] In another aspect, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, it implements the image information differential calculation method based on ramp switching technology provided by the above methods. The method includes: performing temporal and / or spatial differential calculations on two pixel signals of an image through a differential unit 1 to obtain an image pixel differential signal; and switching a ramp signal according to the image pixel differential signal through a switching unit 2.

[0081] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0082] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0083] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An image information difference calculation circuit based on a ramp switching technique, characterized by, include: The differential unit is used to perform temporal and / or spatial difference calculations on two pixel signals of an image to obtain the image pixel difference signal; The switching unit is used to switch the ramp signal according to the image pixel difference signal.

2. The image information difference calculation circuit based on the slope switching technique according to claim 1, characterized by, The pixel signal of the image includes a first pixel value and a second pixel value; The switching unit includes: A comparator is used to switch to an ascending ramp signal when the second pixel value is greater than the first pixel value; or, If the second pixel value is less than the first pixel value, switch to the downhill ramp signal.

3. The image information difference calculation circuit based on the slope switching technique according to claim 2, characterized by, The first input terminal of the comparator is electrically connected to the output terminal of the differential unit, and the second input terminal of the comparator is used to input a rising ramp signal or a falling ramp signal; the comparator is also used to detect the difference between the image pixel differential signal and the ramp signal; The circuit also includes: A counter, the input of which is electrically connected to the output of the comparator, is used to count according to the difference, so as to quantize the image pixel difference signal into the count data of the counter.

4. The image information difference calculation circuit based on the slope switching technique according to claim 3, characterized by, The comparator is used for: When the image pixel difference signal is greater than the ramp signal, the first level is output; or, When the image pixel difference signal is less than the ramp signal, a second level is output; the first level and the second level are opposite levels.

5. The image information difference calculation circuit based on the slope switching technique according to claim 4, characterized by, The first level is a high level, and the second level is a low level; The counter is used for: Counting begins upon receiving a high level from the comparator; The counting stops when a low level is received from the comparator.

6. The image information difference calculation circuit based on the slope switching technique according to claim 1, characterized by, Also includes: The readout unit has its input terminal electrically connected to the output terminal of the pixel unit, and is used to read out the pixel signal of the image using a column-level signal readout method. The storage unit has its input terminal electrically connected to the output terminal of the readout unit and its output terminal electrically connected to the input terminal of the differential unit, and is used to store the pixel signals of the image.

7. The image information difference calculation circuit based on the slope switching technique according to any one of claims 1 to 6, characterized by, The image pixel difference signal is a temporal difference signal and / or a spatial difference signal; the temporal difference signal is the difference signal between the signals of two sampling times of pixels in the same range; The spatial difference signal is the difference signal between the signals of two range pixels at a given distance and at the same sampling time.

8. The image information difference calculation circuit based on the slope switching technique according to claim 7, characterized by, The range of pixels includes multiple pixel units within the fusion range; the pixel signal of the image is the result of fusing the signals of the multiple pixel units within the fusion range into a single output signal.

9. A vision sensor, characterized in that, The system includes a pixel array and an image information differential calculation circuit based on ramp switching technology as described in any one of claims 1 to 8; the image information differential calculation circuit is disposed at the output end of the pixel array; the pixel array includes a plurality of pixel units.

10. A terminal, characterized in that, Including the vision sensor as described in claim 9.

Images