Method and system for efficient transmission of monochromatic video data

Abstract

Embodiments of the present disclosure relate to methods and systems for efficient transmission of monochromatic video data. A method for transmission of monochromatic video data for monochromatic images, wherein three different source monochromatic pixels are encoded by a transmission device into a compressed trichromatic pixel; the compressed three-color pixels are transmitted by a transmission device. The transmitted compressed tricolor pixels are received at a receiving device; and the compressed three-color pixel is decoded by the receiving device into three different sink single-color pixels. A transmission device acquires three different source monochromatic pixels, extracts monochromatic values from each of the three different source monochromatic pixels, and generates compressed trichromatic pixels using the monochromatic values extracted from the three different source monochromatic pixels. The receiving device extracts monochromatic values from the compressed three-color pixels, and associates each of the monochromatic values extracted from the compressed three-color pixels with a respective pixel of three different sink monochromatic pixels.

Description

Technical Field

[0001] The present disclosure relates to methods and systems for efficient transmission of monochrome video data, particularly for laser beam scanning (LBS) applications. Background Art

[0002] As is known, laser beam scanning LBS has been proposed in an increasing number of applications such as augmented reality (AR) and virtual reality (VR), for example, for projecting images in AR / VR headsets, pattern images for 3D (three-dimensional) sensing, and images for automotive applications.

[0003] LBS applications typically use an application processor as a source of video content.The image to be projected is transmitted to a projection system, which includes control circuitry for an optical engine, which includes, for example, a laser projector.

[0004] Figure 1 A simplified block diagram of an exemplary projection system 1 that may be used for LBS applications is shown in FIG.

[0005] The projection system 1 includes an image transmission component 2 ; an image receiving component 3 ; and a projection unit 4 .

[0006] The image transmission component 2 is configured to manage acquisition of images, store images, and transmit images to the image reception component 3 .

[0007] The image transmission component 2 comprises an application processor 12 which may be a microcontroller (MCU—Microcontroller Unit) and includes a central processing unit (CPU) 6 and a memory 8 .

[0008] The application processor 12 may be physically or wirelessly connected to an external image generation unit (not shown), or include an internal image generation unit (not shown).

[0009] The memory 8 may be an embedded memory and is configured to store an image to be (at least partially) projected by the projection unit 4. The image is generally stored as a matrix of pixels, each pixel being associated with three color values.

[0010] The application processor 12 is coupled to the receiving component 3 via a communication control line 10 and a data line 11. The control line 10 and the data line 11 may be physical or wireless.

[0011] The image receiving part 3 is configured to receive the image sent by the image transmitting part 2 and control the projection unit 4 .

[0012] To this end, the image receiving component 3 comprises a projection control unit 13 including a communication controller 15 , for example a microcontroller (μC), a video controller 16 , for example implemented as a field programmable gate array (FPGA), a laser driver 17 and a mirror driver 18 .

[0013] A laser driver 17 is coupled to a plurality of lasers 20 for generating three-color or monochromatic light beams; a mirror driver 18 is coupled to a mirror 21 for generating a scan of the three-color or monochromatic light beams in a manner known per se.

[0014] Here, the communication controller 15 is coupled to the application processor 12 via a control line 10 , and the video controller 16 is coupled to the application processor 12 via a data line 11 .

[0015] The communication controller 15, the video controller 16, the laser driver 17 and the mirror driver 18 are coupled together by internal lines, such as Figure 1 Visible in.

[0016] Typical LBS applications provide for the transmission of high-resolution video feeds, for example greater than 1280×720 pixels at 60 Hz.

[0017] As an embedded system incorporated into a mobile device, it is desirable that a projection system using an LBS application has low power consumption and allows images to be transmitted between an application processor and a projection control unit in an efficient and low-energy manner.

[0018] Recently, MIPIDSI (Mobile Industry Processor Interface Display Serial Interface) technology has been widely used to efficiently transmit images in mobile applications and now represents the standard for smartphones, notebooks, tablets; it is also increasingly used in cameras, industrial electronics, the Internet of Things (IoT), augmented and virtual reality, automobiles, and medical technology.

[0019] However, using the MIPIDSI standard may sometimes be inefficient. In fact, some MIPIDSI external devices only support three-color (RGB) pixels (the data processing interface DPI does not support byte packets); in addition, some devices have limitations in terms of lane speed.

[0020] Therefore, when the image to be transmitted is monochrome, standard transmission according to the MIPI DSI technology may be inefficient and cause bandwidth waste.

[0021] In the case of a high-clock system, unreasonable power consumption may occur; in some cases, the system may not even be able to transmit images when there is a lane speed limit.

[0022] It is sometimes possible to transmit images as MIPI DSI raw packets in non-video mode; however this solution is not a standard for video communications and is not widely supported by some application processors and associated video controllers in projection control units. Summary of the invention

[0023] Embodiments of the present disclosure overcome at least some of the disadvantages and limitations of the prior art and provide efficient transmission of monochrome image data.

[0024] Some embodiments of the present disclosure provide a method, a transmission device, a receiving device, and a system for transmitting monochrome video data.

[0025] In some embodiments, a method for transmitting monochrome video data of a monochrome image includes: encoding three different source monochrome pixels into a compressed three-color pixel at a transmitting device, and transmitting the compressed three-color pixel by the transmitting device. The method includes: receiving the compressed three-color pixel by a receiving device, and decoding the compressed three-color pixel into three different sink monochrome pixels by the receiving device.

[0026] In some embodiments, a transmission device in a system for transmitting monochrome video data includes an encoding unit and a MIPIDSI transmission unit, wherein the encoding unit is configured to encode three different source monochrome pixels into a compressed three-color pixel, and the MIPIDSI transmission unit is configured to transmit the compressed three-color pixel.

[0027] A receiving device in a system for transmitting monochrome video data includes a MIPI receiving unit and a decoding unit. The MIPI receiving unit is configured to receive compressed three-color pixels, and the decoding unit is configured to decode the received compressed three-color pixels into three different sink monochrome pixels.

[0028] In some embodiments, a system for transmitting monochrome video data includes a transmitting device and a receiving device. The transmitting device includes an encoding unit and a MIPI DSI transmission unit, the encoding unit is configured to encode three different source monochrome pixels into a compressed three-color pixel, and the MIPI DSI transmission unit is configured to transmit the compressed three-color pixel. The receiving device includes a MIPI receiving unit and a decoding unit, the MIPI receiving unit is configured to receive the compressed three-color pixel, and the decoding unit is configured to decode the received compressed three-color pixel into three different destination monochrome pixels. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] For the purpose of understanding the invention, embodiments of the invention will now be described purely as non-limiting examples with reference to the accompanying drawings, in which:

[0030] Figure 1is a simplified block diagram of a projection system 1 that can be used for LBS applications;

[0031] Figure 2 is a simplified block diagram of a portion of a projection system according to an embodiment;

[0032] Figure 3 is a diagram showing a method according to an embodiment of the present invention. Figure 2 A flow chart of steps in video transmission of a projection system;

[0033] Figure 4 yes Figure 2 a representation of a memory space compression in a transmission component of a projection system; and

[0034] Figure 5 yes Figure 2 A representation of a compression of the memory space in a receiving component of a projection system. DETAILED DESCRIPTION

[0035] Figure 2 A projection system 30 according to an embodiment is shown.

[0036] The projection system 30 has an image transmission component 31 and an image receiving component 32. Figure 1 The projection unit 4 , the projection unit (not shown) may be included in the projection system 30 .

[0037] The image transmission component 31 and the image receiving component 32 may have Figure 1 The general structure of components 2, 3 is shown. However, components not relevant to the following description are not shown.

[0038] The image transmission component 31 comprises an application processor 35 which may be a microcontroller (MCU—Micro Controller Unit) and includes a central processing unit (CPU) 36 and a first memory 38 .

[0039] Similar to Figure 1 The application processor 35 comprises a circuit arrangement configured to acquire images and store them in a first memory 38 .

[0040] Therefore, the application processor 35 may be physically or wirelessly connected to an external image generation unit (not shown), or include an internal image generation unit (not shown).

[0041] The CPU 36 is configured to manage the transmission of images stored in the memory 38 to the image receiving component 32. To this end, the CPU 36 includes a MIPIDSI video source interface 36 and a compression unit 37, as discussed in detail below.

[0042] The memory 38 may be an embedded memory and is configured to store images to be (at least partially) projected by the projection system 30. The images are typically stored as a matrix of pixels, each pixel being associated with three color values.

[0043] The image receiving component 32 comprises a projection control unit 40 including a video controller 41, for example implemented by a field programmable gate array (FPGA).

[0044] The FPGA 41 implements a MIPIDSI video sink interface 42 and a decompression unit 43 , and is connected to a second memory 45 .

[0045] According to the MIPIDSI standard, the image transmission component 31 and the image receiving component 32 are coupled together via a connection channel 47 , which may be any physical layer.

[0046] The projection system 30 can utilize the MIPI DSI standard to manage the projection of monochrome images in an efficient manner using standard image transmission resources.

[0047] As described above, the standard MIPI DSI system is configured to transmit / receive three-color pixels and is not optimized for transmission / reception of monochrome pixels, wasting bandwidth and energy.

[0048] To address this issue, projection system 30 manages the transmission / reception of monochrome images by compressing the pixels to be transmitted and decompressing them prior to projection.

[0049] To this end, the projection system 30 extracts a single color value from each pixel; generates new three-dimensional pixels (hereinafter also referred to as "pseudo-pixels") according to the monochrome values ​​of three different pixels through the compression unit 37; and transmits the three-color pseudo-pixels through the MIPIDSI video source interface 36, the connection channel 47 and the MIPIDSI video sink interface 42.

[0050] Therefore, the MIPI DSI video source interface 36, the connection channel 47 and the MIPI DSI video sink interface 42 may be standard components.

[0051] The three-dimensional pseudo pixels received at the image receiving component 32 are decompressed at the decompression unit 43 by generating three different monochrome pixels from each three-dimensional pseudo pixel. The decompressed monochrome pixels can be stored in the second memory 45 (sorted according to their order in the first memory 38) for their projection, such as for Figure 1 The projection system 1 is as described.

[0052] The pixels from the first memory 38 may be adjacent pixels along a row or column of the matrix and are arranged in the same row or column order in the second memory 45 .

[0053] A possible process 50 performed by the compression unit 37 of the application processor 35 is shown in Figure 3 In order to simplify the description, sequential (serial) processing of pixels of an image is described.

[0054] However, in general, the application processor 35 operates in a highly parallel manner, processing all or most of the pixels of an image in parallel. Figure 3 The order of processing shown should not be considered limiting.

[0055] In the following description, the following definitions apply:

[0056] Three-color pixel: A standard image pixel represented by a set of three color values ​​(RGB);

[0057] Monochrome value: a value extracted from a three-color pixel of a monochrome image and indicating monochrome information (e.g., a monochrome value associated with one color (e.g., green G) or any value derived from processing (e.g., averaging) three-color pixels), which can be reconverted into a standard three-color pixel;

[0058] Compressed pixel: A collection of three monochrome values ​​extracted from three different tri-color pixels.

[0059] refer to Figure 3 , step 52, initialize counter i at pixel index (px_index).

[0060] In step 54 , the position of the pixel i and the positions of two consecutive pixels i+1 and i+2 are acquired and stored in a position vector vec2 within the CPU 36 .

[0061] In step 56 , the monochrome values ​​of pixels i, i+1 and i+2 are extracted, for example by multiplying the three-color pixels whose positions are stored in vector vec2 by the extraction matrix; the result is stored in value vector vec4 within CPU 36 .

[0062] In step 58, compressed pixels are generated including the monochrome values ​​of pixels i, i+1, and i+2.

[0063] In step 60, processing of the entire image is checked; if not all pixels have been processed, N is output from step 60 and the flow proceeds to step 62 to obtain the subsequent pixel index and go to step 50 as described above.

[0064] If all pixels have been extracted, Y is output from step 60 and the process ends.

[0065] The results are also Figure 4 is conceptually presented in FIG. 1 , showing a plurality of pixels p i 、p i+1 、p i+2 ,…,p n The first memory 38 stores three color values ​​for each pixel; the process 50 performs the color calculation on the pixel p i 、p i+1 、p i+2 and the resulting memory 47 (embedded in the application processor 35) has compressed pixels p j , the compressed pixel p j The first memory 38 contains pixels p i 、p i+1 、p i+2 The same information, but stored in a single location.

[0066] Therefore, assuming that the first memory 38 has a width W and a height h (total size: W×h), the pixel memory 48 can have a total size (W×h) / 3, for example, a width W / 3 and a height h (or the same width W and height h / 3 or any other combination of the above total sizes).

[0067] The memory 48 may not be a physical memory but an abstraction of a data flow.

[0068] The decompression at the decompression unit 43 of the projection control unit 40 may be the reverse of the process 50: in particular, referring to Figure 2 , the decompression unit 43 may:

[0069] Extract compressed pixel p j The first color value of

[0070] Processing compressed pixel p j to obtain a first set of decompressed three-color values ​​and compare them with the decompressed pixel P k associated;

[0071] Extract compressed pixel p j The second color value of

[0072] Processing compressed pixel p j to obtain a second set of decompressed three-color values ​​and compare them with the decompressed pixel P k+1 associated;

[0073] Extract compressed pixel p j a third color; and

[0074] Processing compressed pixel p j to obtain a third set of decompressed three-color values ​​and compare them with the decompressed pixel p k+2 Associated.

[0075] By compressing the image into compressed pixels having three times the information content relative to the original image, standard MIPI DSI transmission techniques can be used and the bandwidth for transmission is optimized.

[0076] Additionally, it may also be possible to use devices with MIPI DSI clock speed limitations.

[0077] The system has low resource occupation and low power consumption.

[0078] Furthermore, the adaptation of the existing architecture only involves the implementation of the compression and decompression units 36 , 43 , ie changes to the application processor 35 and the video controller 41 are minimal.

[0079] Finally, it will be apparent that numerous changes and modifications may be made to the systems and methods described and illustrated herein, all falling within the scope of the present disclosure as defined in the appended claims.

[0080] In some embodiments, a method for transmitting monochrome video data of a monochrome image includes: encoding three different source monochrome pixels into a compressed three-color pixel at a transmitting device (31); transmitting the compressed three-color pixel by the transmitting device; receiving the compressed three-color pixel by a receiving device (32); and decoding the compressed three-color pixel into three different destination monochrome pixels by the receiving device.

[0081] In some embodiments, encoding includes: obtaining three different source monochrome pixels, each source monochrome pixel being associated with a three-color value; extracting a monochrome value from each of the three different source monochrome pixels; and generating a compressed three-color pixel using the monochrome values ​​extracted from the three different source monochrome pixels.

[0082] In some embodiments, decoding includes: extracting monochrome values ​​from the compressed three-color pixels; and associating each of the monochrome values ​​extracted from the compressed three-color pixels with a respective one of three different sink monochrome pixels.

[0083] In some embodiments, the three different source monochrome pixels are the first three different source monochrome pixels of the monochrome image, and the encoding also includes: obtaining three different additional source monochrome pixels in the monochrome image, each additional source monochrome pixel being associated with corresponding three color values; extracting a monochrome value from each of the three different additional source monochrome pixels; and generating additional compressed three-color pixels using the monochrome values ​​extracted from the three different additional source monochrome pixels.

[0084] In some embodiments, three different additional source monochrome pixels are processed in parallel with the first three different source monochrome pixels.

[0085] In some embodiments, transmitting includes using the RGB MIPIDSI protocol.

[0086] In some embodiments, the method includes: the three different source monochrome pixels are adjacent pixels in the monochrome image.

[0087] In some embodiments, the monochrome image comprises a matrix of pixels arranged in a plurality of rows and a plurality of columns, wherein adjacent pixels in the monochrome image may be adjacent pixels in a row of the plurality of rows or adjacent pixels in a column of the plurality of columns.

[0088] In some embodiments, a transmission device (31) in a system (30) for transmitting monochrome video data includes: an encoding unit (37) configured to encode three different source monochrome pixels into a compressed three-color pixel; and a MIPIDSI transmission unit (36) configured to transmit the compressed three-color pixel.

[0089] In some embodiments, the encoding unit (37) is configured to: obtain three different source monochrome pixels, each source monochrome pixel being associated with a three-color value; extract a monochrome value from each of the three different source monochrome pixels; and generate a compressed three-color pixel using the monochrome values ​​extracted from the three different source monochrome pixels.

[0090] In some embodiments, the three different source monochrome pixels are the first three different source monochrome pixels of the monochrome image, and the encoding unit (37) is further configured to: obtain three different additional source monochrome pixels in the monochrome image, each additional source monochrome pixel being associated with corresponding three color values; extract a monochrome value from each of the three different additional source monochrome pixels; and generate additional compressed three-color pixels using the monochrome values ​​extracted from the three different additional source monochrome pixels.

[0091] In some embodiments, three different additional source monochrome pixels are processed in parallel with the first three different source monochrome pixels.

[0092] In some embodiments, a receiving device (32) in a system (30) for transmission of monochrome video data includes: a MIPI receiving unit (42) configured to receive compressed three-color pixels; and a decoding unit (43) configured to decode the received compressed three-color pixels into three different destination monochrome pixels.

[0093] In some embodiments, the decoding unit is configured to extract the received compressed three-color pixel pj The extracted first color and the first host monochrome pixel p of three different host monochrome pixels k Associate; extract the received three-color pixel p j The extracted second color and the second sink monochrome pixel p of three different sink monochrome pixels k+1 Associate; extract the received three-color pixel p j and extracting the third color and the third sink monochrome pixel p in three different sink monochrome pixels. k+2 Associated.

[0094] A system (30) for transmission of monochrome video data comprises a transmission device (31) and a reception device (32).

[0095] Based on the above detailed description, the above and other changes can be made to the embodiments. In general, in the appended claims, the terms used should not be interpreted as limiting the claims to the specific embodiments disclosed in the specification and claims, but should be interpreted to include all possible embodiments and the full range of equivalents to which these claims are entitled. Therefore, the claims are not limited by this disclosure.

Claims

1. A method for transmitting monochrome video data of a monochrome image, comprising: encoding three different source monochrome pixels into one compressed three-color pixel at a transmission device; Transmitting the compressed three-color pixels by the transmission device; Receiving the compressed three-color pixel by a receiving device; as well as The compressed three-color pixel is decoded by the receiving device into three different sink single-color pixels.

2. The method of claim 1 , wherein encoding the three different source monochrome pixels comprises: Acquire the three different source monochrome pixels, each source monochrome pixel being associated with three color values; extracting a monochrome value from each of the three different source monochrome pixels; as well as The compressed three-color pixel is generated using the monochrome values ​​extracted from the three different source monochrome pixels.

3. The method of claim 2, wherein decoding the compressed three-color pixels comprises: extracting the monochrome value from the compressed three-color pixel; as well as Each of the monochrome values ​​extracted from the compressed three-color pixels is associated with a respective one of the three different sink monochrome pixels.

4. The method of claim 2, wherein the three different source monochrome pixels are first three different source monochrome pixels of the monochrome image, and wherein encoding further comprises: Acquire three different additional source monochrome pixels in the monochrome image, each additional source monochrome pixel being associated with corresponding three color values; extracting a monochrome value from each of the three different additional source monochrome pixels; as well as Further compressed three-color pixels are generated using the monochrome values ​​extracted from the three different further source monochrome pixels.

5. The method of claim 4, wherein the three different additional source monochrome pixels are processed in parallel with the first three different source monochrome pixels.

6. The method of claim 1, wherein transmitting comprises: The RGB MIPIDSI protocol is used.

7. The method of claim 1, wherein the three different source monochrome pixels are adjacent pixels in the monochrome image.

8. The method of claim 1, wherein the monochrome image comprises a matrix of pixels arranged in a plurality of rows and a plurality of columns, wherein the adjacent pixels in the monochrome image are adjacent pixels in a row of the plurality of rows or adjacent pixels in a column of the plurality of columns.

9. The method of claim 1, wherein the receiving device is coupled to a projection unit.

10. A transmission device in a system for transmitting monochrome video data, comprising: an encoding unit, the encoding unit being configured to encode three different source monochrome pixels into one compressed three-color pixel; as well as A MIPI DSI transmission unit is configured to transmit the compressed three-color pixels.

11. The transmission device according to claim 10, wherein the encoding unit is configured to: Acquire the three different source monochrome pixels, each source monochrome pixel being associated with three color values; extracting a monochrome value from each of the three different source monochrome pixels; and The compressed three-color pixel is generated using the monochrome values ​​extracted from the three different source monochrome pixels.

12. The transmission device according to claim 10, wherein the three different source monochrome pixels are first three different source monochrome pixels of the monochrome image, and the encoding unit is further configured to: Acquire three different additional source monochrome pixels in the monochrome image, each additional source monochrome pixel being associated with a corresponding trichromatic value; extracting a monochrome value from each of the three different further source monochrome pixels; and Further compressed three-color pixels are generated using the monochrome values ​​extracted from the three different further source monochrome pixels.

13. The transmission device of claim 12, wherein the three different additional source monochrome pixels are processed in parallel with the first three different source monochrome pixels. The transmission device according to claim 10 , wherein the encoding unit is a multiplexing unit.

15. The transmission device of claim 11, comprising a memory configured to store a matrix of pixels.

16. A receiving device in a system for transmitting monochrome video data, comprising: A MIPI receiving unit, wherein the MIPI receiving unit is configured to receive compressed three-color pixels; as well as A decoding unit is configured to decode the received compressed three-color pixels into three different sink single-color pixels.

17. The receiving device according to claim 16, wherein the decoding unit is configured to: Extract the received compressed three-color pixel p j The first color; The extracted first color is combined with the first sink monochrome pixel p of the three different sink monochrome pixels. k associated; Extract the received three-color pixel p j The second color; The extracted second color is combined with the second sink monochrome pixel p of the three different sink monochrome pixels. k+1 associated; Extract the received three-color pixel p j a third color; and The extracted third color is combined with the third sink monochrome pixel p of the three different sink monochrome pixels. k+2 Associated. The receiving device according to claim 17 , wherein the decoding unit is a demultiplexing unit.

19. The receiving device of claim 17, comprising a field programmable gate array. 20 . The receiving device according to claim 19 , wherein the MIPI receiving unit is implemented in the field programmable gate array.

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