A method for determining image display delay

Abstract

The present invention provides a method for determining image display delay, the method comprising: determining a first delay time required from capturing an image to decoding the image to generate a decoded image; determining a second delay time from generating the decoded image to displaying it on a display terminal; and determining a maximum delay time for image display. The present invention provides accurate benchmark data for detecting whether a product image display delay parameter is qualified.

Description

Technical Field

[0001] The present invention relates to the field of image technology, and in particular to a method for determining image display delay. Background Art

[0002] In recent years, with the rapid development and popularization of intelligent cockpit technology, electronic exterior rearview mirrors have gradually become the new favorite of major car manufacturers. Electronic exterior rearview mirrors use wide-angle cameras to capture the rear view of the car, widen the left and right sides of the field of vision, reduce blind spots, and add waterproof and stain-resistant, rain shelter and electric heating functions. They not only provide drivers with higher-definition and wider rear view images, but also avoid adverse effects caused by weather and other environmental factors. At the same time, they also integrate a wealth of ADAS functions, solving the pain point of drivers not being able to see the rearview mirror clearly, making driving safer.

[0003] Traditional exterior rearview mirrors use the principle of light reflection to form images, and there is almost no time delay. However, due to the need for signal conversion, image decoding, display imaging processing, etc., time delays will occur. Relevant regulations clearly require that the delay time of the electronic exterior rearview mirror system should not exceed 200ms, and some car manufacturers require it not to exceed 150ms. How to effectively determine the time delay of the electronic exterior rearview mirror display image, ensure the timeliness of the rearview image, and make the product meet the requirements of functional safety is a technical problem that electronic exterior rearview mirror manufacturers urgently need to solve. Summary of the invention

[0004] The present invention provides a method for determining image display delay, aiming to solve the defects in the prior art and provide accurate benchmark data for detecting whether the image display delay parameters of a product are qualified.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] The present invention provides a method for determining image display delay, comprising:

[0007] Step 1: determining a first delay time required from capturing an image to decoding the image to generate a decoded image;

[0008] Step 2, determining a second delay time from generating a decoded image to displaying it on a display terminal;

[0009] Step 3: Determine the maximum delay time for image display.

[0010] Specifically, the step 1 includes:

[0011] Step 101: Establish an acquisition image information table, wherein the acquisition image information table includes: an acquisition image timestamp and at least one acquisition feature CRC value;

[0012] Step 102: Obtain the first acquired image timestamp, the second acquired image timestamp and the interval frame number thereof from the acquired image information table;

[0013] Step 103: Obtain a first delay time according to the first acquired image timestamp and the second acquired image timestamp.

[0014] Specifically, the first delay time is the absolute value of the difference between the first acquired image timestamp and the second acquired image timestamp divided by the interval frame number.

[0015] Specifically, the step 2 includes: determining the second delay time by acquiring a target display feature CRC value of a target display image, where the target display image is a previous frame display image.

[0016] Specifically, the step 2 includes:

[0017] Step 201: setting a check area corresponding to the acquisition feature CRC value on the display terminal;

[0018] Step 202, reading and recording the target display feature CRC value of the target display image at a preset period;

[0019] Step 203, obtaining a reading timestamp of the target display characteristic CRC value;

[0020] Step 204: Determine a target display timestamp of the target display image;

[0021] Step 205, determining a target image decoding timestamp of the target display image according to the target display feature CRC value;

[0022] Step 206: Determine the second delay time according to the target display timestamp and the target image decoding timestamp.

[0023] Specifically, the target display timestamp display_timetick=max{read_timetick-0,read_timetick-(1 / f)}, where read_timetick represents the read timestamp, f represents the display frame rate, and max{} represents taking the larger one.

[0024] Specifically, step 205 includes:

[0025] Step 205a, traverse the collected image information table, and mark the collected image corresponding to the collection feature CRC value that is the same as the target display feature CRC value as the target collected image;

[0026] Step 205b: Obtain a target image decoding timestamp of the target acquired image.

[0027] Specifically, the second delay time is the difference between the target display timestamp and the target image decoding timestamp.

[0028] Specifically, the maximum delay time is the sum of the first delay time and the second delay time.

[0029] Furthermore, after step 3, the method further includes:

[0030] Step 4: determine whether the maximum delay time is lower than the target delay time, if yes, it is determined to be qualified, otherwise, it is determined to be unqualified.

[0031] The beneficial effects of the present invention are as follows: the present invention establishes an acquisition image information table, obtains the first acquisition image timestamp, the second acquisition image timestamp and the number of interval frames therebetween from the acquisition image information table, thereby obtaining the first delay time, and sets a check area corresponding to the acquisition feature CRC value on the display terminal, reads the target display feature CRC value, reads the timestamp, and the target display timestamp, thereby obtaining the second delay time, and finally determines the maximum delay time of the image display, thereby providing accurate benchmark data for detecting whether the product image display delay parameters are qualified. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a flow chart of the method for determining image display delay of the present invention. DETAILED DESCRIPTION

[0033] The following specifically describes the embodiments of the present invention in conjunction with the accompanying drawings, which are only for reference and illustration and do not constitute a limitation on the scope of patent protection of the present invention.

[0034] In the process described in the specification, claims or drawings of the present invention, the serial numbers of each step (such as step 10, 20, etc.) are included. The serial numbers are only used to distinguish the steps, and the serial numbers themselves do not represent any execution order. It should be noted that the descriptions such as "first" and "second" in this article are only used to distinguish the description objects, etc., and do not represent the order of precedence, nor do they mean that "first", "second", etc. are different types.

[0035] like Figure 1 As shown, the present invention provides a method for determining image display delay, comprising:

[0036] Step 1: Determine a first delay time T1 required from capturing an image to decoding the image to generate a decoded image.

[0037] In this embodiment, step 1 includes:

[0038] Step 101: Establish an acquired image information table, wherein the acquired image information table includes: an acquired image timestamp info_timetick and at least one acquired feature CRC value.

[0039] In this embodiment, when the system collects images, it uses the system time to timestamp the collected images to obtain the collected image timestamp info_timetick.

[0040] The acquisition feature CRC value is the CRC value of any area in the acquisition image.

[0041] Preferably, the acquisition feature CRC value includes a first acquisition feature CRC value and a second acquisition feature CRC value, wherein the first acquisition feature CRC value is obtained by selecting a first preset pixel (e.g., 32*32 pixels) from the first region of the acquired image and calculating its CRC value, and the second acquisition feature CRC value is obtained by selecting a first preset pixel (e.g., 32*32 pixels) from the second region of the acquired image and calculating its CRC value. Of course, the pixel sizes of the first region and the second region may also be different, for example, the first region is 32*32 pixels and the second region is 64*64 pixels, and the positions of the first region and the second region may be symmetrical or asymmetrical.

[0042] In this embodiment, for the convenience of calculation, preferably, the pixel sizes of the first area and the second area are the same, and the positions are symmetrically distributed about the center of the acquired image.

[0043] For each frame of collected image, after obtaining the collected image information (collected image timestamp, characteristic CRC value), it is saved in the collected image information table. For ease of implementation, the collected image information table is set to 50 entries.

[0044] Step 102: Obtain the first acquired image timestamp info_timetick1, the second acquired image timestamp info_timetick2 and the interval frame number N thereof from the acquired image information table.

[0045] Step 103: Obtain a first delay time T1 according to the first acquired image timestamp info_timetick1 and the second acquired image timestamp info_timetick2.

[0046] In this embodiment, the first delay time T1 is the absolute value of the difference between the first acquired image timestamp info_timetick1 and the second acquired image timestamp info_timetick2 divided by the interval frame number N.

[0047] Step 2: Determine a second delay time T2 from generating the decoded image to displaying it on the display terminal.

[0048] In this embodiment, the step 2 includes: determining the second delay time T2 by acquiring a target display feature CRC value of a target display image, where the target display image is a previous frame display image.

[0049] In specific implementation, the display terminal needs to have the function of calculating the corresponding target display feature CRC value.

[0050] In this embodiment, step 2 includes:

[0051] Step 201: Setting a check area corresponding to the acquisition feature CRC value on the display terminal.

[0052] For example, if the acquisition feature CRC value is a left and right acquisition feature CRC value, then the verification area of ​​the target display feature CRC value also includes left and right verification areas of the same size and position.

[0053] Step 202: Read and record the target display feature CRC value of the target display image at a preset period.

[0054] In this embodiment, the target display characteristic CRC value is implemented by hardware. In theory, the CRC value of the previous frame of display image can be read when the current frame is displayed, but considering the reading performance of the system and the time range of the required image delay, it is more reasonable to set the preset period to 100ms.

[0055] Step 203: Obtain a read timestamp read_timetick for reading the target display feature CRC value.

[0056] Step 204: Determine a target display timestamp display_timetick of the target display image.

[0057] In this embodiment, the target display timestamp display_timetick=max{read_timetick-0, read_timetick-(1 / f)}, where f is the display frame rate, and max{} indicates taking the larger one.

[0058] Step 205: Determine a target image decoding timestamp info_timetick of the target display image according to the target display feature CRC value.

[0059] In this embodiment, step 205 includes:

[0060] Step 205a, traverse the collected image information table, and mark the collected image corresponding to the collection feature CRC value that is the same as the target display feature CRC value as the target collected image;

[0061] Step 205b: Obtain the target image decoding timestamp info_timetick of the target acquired image.

[0062] Step 206: Determine the second delay time T2 according to the target display timestamp and the target image decoding timestamp.

[0063] In this embodiment, the second delay time T2 is the difference between the target display timestamp and the target image decoding timestamp.

[0064] Step 3: Determine the maximum delay time T for image display.

[0065] In this embodiment, the maximum delay time T is the sum of the first delay time T1 and the second delay time T2.

[0066] In another embodiment of the present invention, after step 3, the method further includes:

[0067] Step 4: Determine whether the maximum delay time T is lower than the target delay time T0. If so, it is determined to be qualified; otherwise, it is determined to be unqualified.

[0068] In this embodiment, the target delay T0 is the maximum delay required by the customer.

[0069] The above disclosure is only a preferred embodiment of the present invention, which cannot be used to limit the scope of protection of the present invention. Therefore, equivalent changes made according to the scope of the patent application of the present invention are still within the scope covered by the present invention.

Claims

1. A method for determining image display delay, characterized in that: include: Step 1: determining a first delay time required from capturing an image to decoding the image to generate a decoded image; Step 2, determining a second delay time from generating a decoded image to displaying it on a display terminal; Step 3, determining the maximum delay time of image display; The step 1 comprises: Step 101: Establish an acquisition image information table, wherein the acquisition image information table includes: an acquisition image timestamp and at least one acquisition feature CRC value; Step 102: Obtain the first acquired image timestamp, the second acquired image timestamp and the interval frame number thereof from the acquired image information table; Step 103: Obtain a first delay time according to the first acquired image timestamp and the second acquired image timestamp, wherein the first delay time is the absolute value of the difference between the first acquired image timestamp and the second acquired image timestamp divided by the interval frame number; The step 2 includes: determining the second delay time by acquiring a target display feature CRC value of a target display image, where the target display image is a previous frame display image.

2. The method for determining image display delay according to claim 1, characterized in that: The step 2 comprises: Step 201: setting a check area corresponding to the acquisition feature CRC value on the display terminal; Step 202, reading and recording the target display feature CRC value of the target display image at a preset period; Step 203, obtaining a reading timestamp of the target display characteristic CRC value; Step 204: Determine a target display timestamp of the target display image; Step 205, determining a target image decoding timestamp of the target display image according to the target display feature CRC value; Step 206: Determine the second delay time according to the target display timestamp and the target image decoding timestamp.

3. The method for determining image display delay according to claim 2, characterized in that: The target display timestamp display_timetick=max{read_timetick-0,read_timetick-(1 / f)}, where read_timetick represents the read timestamp, f represents the display frame rate, and max{} represents taking the larger one.

4. The method for determining image display delay according to claim 2, characterized in that: The step 205 comprises: Step 205a, traverse the collected image information table, and mark the collected image corresponding to the collection feature CRC value that is the same as the target display feature CRC value as the target collected image; Step 205b: Obtain a target image decoding timestamp of the target acquired image.

5. The method for determining image display delay according to claim 4, characterized in that: The second delay time is the difference between the target display timestamp and the target image decoding timestamp.

6. The method for determining image display delay according to claim 1, characterized in that: The maximum delay time is the sum of the first delay time and the second delay time.

7. The method for determining image display delay according to claim 6, characterized in that: After step 3, the method further includes: Step 4: determine whether the maximum delay time is lower than the target delay time, if yes, it is determined to be qualified, otherwise, it is determined to be unqualified.

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