CN106454329A - Image acquisition detection system and method - Google Patents

Abstract

The present invention relates to an image acquisition and detection system and method, wherein the image acquisition and detection system includes a signal acquisition module connected to the sink end of a digital high-definition transmission interface, a test source module, and a video signal connected between the signal acquisition module and the test source module. Image evaluation module; the test source module outputs the test source to the sink end of the digital high-definition transmission interface, and the sink end of the digital high-definition transmission interface outputs the corresponding video image signal based on the test source; the signal acquisition module collects in real time according to the corresponding control signal of the video image evaluation module The video image signal is sent to the video image evaluation module; the video image evaluation module performs quality inspection processing on the video image signal to obtain an image quality inspection result. The invention can accurately measure the video transmission quality of the digital high-definition transmission interface, and locate defects more efficiently.

Description

Image acquisition and detection system and method

technical field

The invention relates to the technical field of digital high-definition interface image acquisition, in particular to an image acquisition and detection system and method.

Background technique

The digital high-definition transmission interface is a digital channel used to transmit high-definition audio and video. It is compatible with many formats of video transmission, such as 1080P, 2K, 4K, etc., and can be connected to high-definition playback devices, such as: DVD player, Blu-ray DVD player, hard disk High-definition player, computer, satellite receiver, set-top box and other program sources. The digital high-definition transmission interface can transmit audio and video signals at the same time. Since the audio and video signals use the same cable, it can overcome the problems of VGA (Video Graphics Array), DVI (Digital Display Working Group) and other interfaces. Audio and video data cannot be transmitted through one line To solve the problem, the interface connector adopts a single-wire connection, which replaces the complicated cables behind the product and greatly simplifies the installation of the system.

However, due to the complex interface technology of the digital high-definition transmission interface, there are differences in the technical level and implementation methods of various manufacturers. Especially in China, various products without authorization or standard compliance testing are introduced to the market, resulting in poor interconnection and interoperability of current digital high-definition transmission equipment. Moreover, there are many types and quantities of equipment using digital high-definition transmission interfaces, but the low test efficiency also limits the further development of the interfaces.

During the implementation process, the inventors found at least the following problems in the traditional technology: the traditional high-definition interface video signal quality analysis is mainly based on the subjective evaluation of the observer, that is, the observer evaluates the image quality transmitted to the screen by the high-definition transmission interface. However, subjective quality evaluation is time-consuming, expensive, and is very easily affected by factors such as the experimental environment, the observer's knowledge level, and their own preferences. The evaluation results are often inaccurate and unstable. Secondly, the quality of the LCD screen has a great impact on the final subjective scoring results, and the traditional method cannot avoid the interference of the LCD screen, and cannot accurately measure the video transmission quality of the digital high-definition transmission interface and locate defects.

Contents of the invention

Based on this, it is necessary to provide an image acquisition and detection system and method for the problem that the traditional technology cannot accurately measure the image quality of the digital high-definition interface.

In order to achieve the above object, the embodiment of the technical solution of the present invention is:

On the one hand, an image acquisition and detection system is provided, including a signal acquisition module connected to a sink end of a digital high-definition transmission interface, a test source module, and a video image evaluation module connected between the signal acquisition module and the test source module;

The test source module outputs the test source to the sink end of the digital high-definition transmission interface, and the sink end of the digital high-definition transmission interface outputs the corresponding video image signal based on the test source;

The signal acquisition module collects the video image signal in real time according to the corresponding control signal of the video image evaluation module, and sends the video image signal to the video image evaluation module;

The video image evaluation module performs quality detection processing on video image signals to obtain image quality detection results; quality detection processing includes single-frame/multi-frame acquisition processing of video image signals, image objective evaluation processing, difference positioning processing and comparative analysis.

In another aspect, an image acquisition and detection method is provided, comprising the following steps:

Output the test source to the sink end of the digital high-definition transmission interface;

Real-time collection of LVDS signals output by the digital high-definition transmission interface sink based on the test source;

Perform quality inspection processing on LVDS signals to obtain image quality inspection results; quality inspection processing includes single-frame/multi-frame acquisition processing of LVDS signals, image objective evaluation processing, difference positioning processing, and comparative analysis.

The above technical scheme has the following beneficial effects:

The image acquisition and detection system and method of the present invention, by using the transmission interface connected between the interface board and the liquid crystal screen in the sink device of the digital high-definition transmission interface as the test boundary, avoids the interference of the liquid crystal screen on the test results, and accurately measures the digital high-definition transmission interface Excellent video transmission quality, more efficient location of defects, while reducing test costs, save a lot of time and energy of test engineers, making testing easier and easier.

Description of drawings

Fig. 1 is a schematic structural view of Embodiment 1 of the image acquisition and detection system of the present invention;

Fig. 2 is a schematic structural diagram of the signal acquisition module in Embodiment 1 of the image acquisition and detection system of the present invention;

Fig. 3 is a schematic structural diagram of the video image evaluation module in Embodiment 1 of the image acquisition and detection system of the present invention;

4 is a schematic diagram of the functional flow of the image video single frame acquisition module in the video image evaluation module in Embodiment 1 of the image acquisition and detection system of the present invention;

5 is a schematic diagram of the functional flow of the image and video multi-frame acquisition module in the video image evaluation module in Embodiment 1 of the image acquisition and detection system of the present invention;

6 is a schematic diagram of the functional flow of the image and video analysis module in the video image evaluation module in Embodiment 1 of the image acquisition and detection system of the present invention;

Fig. 7 is a schematic diagram of the functional implementation structure of Embodiment 2 of the image acquisition and detection system of the present invention;

8 is a schematic diagram of video image analysis and testing in Embodiment 2 of the image acquisition and detection system of the present invention;

Fig. 9 is a schematic diagram of the audio transmission quality test of Embodiment 2 of the image acquisition and detection system of the present invention;

Fig. 10 is a schematic diagram of image differential positioning in Embodiment 2 of the image acquisition and detection system of the present invention;

FIG. 11 is a schematic flowchart of Embodiment 1 of the image acquisition and detection method of the present invention.

detailed description

In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the associated drawings. A preferred embodiment of the invention is shown in the drawings. However, the present invention can be embodied in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of the present invention will be thorough and complete.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field of the invention. The terms used herein in the description of the present invention are for the purpose of describing specific embodiments only, and are not intended to limit the present invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

In order to clearly illustrate the technical solution of the present invention, the abbreviations and key terms involved in the various embodiments of the present invention are explained:

LVDS: Low-Voltage Differential Signaling, low voltage differential signal. High-speed differential transmission of data with extremely low voltage swing can realize point-to-point or point-to-multipoint connection. It has the characteristics of low power consumption, low bit error rate, low crosstalk and low radiation. The transmission medium can be copper The PCB connection can also be a balanced cable.

MSE: Mean Squared Error, mean square error, is a more convenient way to measure the "average error", which can evaluate the degree of change in the data.

PSNR: Peak Signal to Noise Ratio, peak signal to noise ratio, a full-reference image quality evaluation index, is based on the error between corresponding pixels, that is, based on error-sensitive image quality evaluation.

SSIM: Structural Similarity Index, structural similarity, is an index to measure the similarity of two images. The structural similarity index defines structural information from the perspective of image composition as being independent of brightness and contrast, reflecting the properties of object structures in the scene, and modeling distortion as a combination of three different factors of brightness, contrast and structure.

D-SSIM: Dynamic structural similarity, an objective evaluation algorithm based on SSIM and adding a color model, is more suitable for the evaluation of high-definition images.

Sink end: The receiving end of the digital high-definition transmission interface, such as TV, tablet, smart phone, notebook, etc.

Objective quality evaluation: The objective evaluation method of image quality is relative to the subjective evaluation. According to the use of mathematical methods, a mathematical model is established, and the image quality is calculated through specific formulas.

Embodiment 1 of the image acquisition and detection system of the present invention:

In order to solve the problem that the traditional technology cannot accurately measure the image quality of the digital high-definition interface, the present invention provides an image acquisition and detection system embodiment 1; FIG. 1 is a schematic structural diagram of the image acquisition and detection system embodiment 1 of the present invention; as shown in FIG. 1 , may include a signal acquisition module connected to the sink end of the digital high-definition transmission interface, a test source module, and a video image evaluation module connected between the signal acquisition module and the test source module;

The test source module outputs the test source to the sink end of the digital high-definition transmission interface, and the sink end of the digital high-definition transmission interface outputs the corresponding video image signal based on the test source;

The signal acquisition module collects the video image signal in real time according to the corresponding control signal of the video image evaluation module, and sends the video image signal to the video image evaluation module;

The video image evaluation module performs quality detection processing on video image signals to obtain image quality detection results; quality detection processing includes single-frame/multi-frame acquisition processing of video image signals, image objective evaluation processing, difference positioning processing and comparative analysis.

Specifically, as shown in Figure 1, the entire technical solution consists of two parts. On the right is the test evaluation system, which is mainly composed of LVDS signal acquisition module, video image evaluation module and test source module. On the left is the sink end of the digital high-definition transmission interface, which is the object under test. The invention provides a test boundary using the connection point between LVDS and LCD screen, which avoids the influence of defects such as color difference, color shift, and blur of the LCD screen on the test results, and realizes lossless collection of images transmitted by digital high-definition interfaces and method for rapid detection. The system mainly consists of LVDS signal acquisition module, video image evaluation module and test source module.

This method of using LVDS as the test boundary can greatly save the troubles of low efficiency of subjective test and interference of the screen to the test result. While reducing the test cost, it saves a lot of time and energy of the test engineer. The test of the image transmission quality of the high-definition transmission interface becomes simpler and easier.

Fig. 2 is the structural representation of the signal acquisition module in the embodiment 1 of the image acquisition detection system of the present invention; As shown in Fig. 2, in a specific embodiment, the signal acquisition module is an LVDS signal acquisition module; The LVDS output interface at the sink end of the transmission interface is connected; the video image signal is an LVDS signal.

The relevant technical indicators of the LVDS signal acquisition module can be as follows:

Analog signal channel: the number of channels for collecting data is 32 channels, which can be expanded to 64 channels;

Sampling word length: 16 bits;

Signal amplitude: 0-5V;

Single channel maximum sampling rate: 50KHz;

Total sampling rate: no more than 2MHz;

Sampling error: no more than one thousandth;

Storage capacity: not less than 1Gbyte;

Input impedance: about 2MΩ;

Data bus type: LVDS bus.

The acquisition module selects FPGA as the main control module to realize the acquisition, data storage and upload of the digital high-definition transmission interface LVDS signal. Since FPGA has high-speed processing, rich I/O and resources, it can process a large number of data signals in parallel.

Specifically, by using the LVDS interface connected between the interface board and the LCD screen in the sink device of the digital high-definition transmission interface, as the boundary of the test, the interference of the LCD screen on the test results is avoided, and the video transmission of the digital high-definition transmission interface can be accurately measured quality and locate defects more efficiently.

In a specific embodiment, the signal acquisition module includes an FPGA main control module;

The FPGA main control module performs parallel acquisition and image reconstruction processing on the LVDS signal, and transmits the processed LVDS signal to the video image evaluation module.

Specifically, FPGA (Field-Programmable Gate Array) is selected as the main control module, which can realize the acquisition, data storage and upload of digital high-definition transmission interface LVDS signal. Because FPGA has high-speed processing, rich I/O and resources, it can process a large number of data signals in parallel, and realizes the video lossless acquisition of the interface processing of the sink.

At the same time, a SoC system-on-a-chip can be used to implement the functions of the signal acquisition module in each embodiment of the present invention, by performing parallel acquisition and image reconstruction on LVDS signals. The FPGA acquisition module has the cache capacity of saving 16 frames of images, can evaluate the characteristics of video stream frame-to-frame jitter, and has real-time reconstruction of images, and can observe the test results in real time with an external monitor.

Fig. 3 is the structural representation of video image evaluation module in the embodiment 1 of image collection detection system of the present invention; As shown in Fig. 3, video image evaluation module video image evaluation module can comprise 5 large modules (image video single frame acquisition module, image video Multi-frame acquisition module, display module, image and video difference positioning module, and image and video analysis module), mainly to control the acquisition module, and realize single-frame/multi-frame acquisition of image and video, objective image evaluation, difference positioning and The result graph is displayed.

In a specific embodiment, the video image evaluation module may include an image video single-frame acquisition module, an image video multi-frame acquisition module and a display module;

The image video single frame acquisition module outputs the first acquisition control signal to the signal acquisition module, and the signal acquisition module carries out the real-time acquisition of the static video frame to the video image signal according to the first acquisition control signal;

The image video multi-frame acquisition module outputs the second acquisition control signal to the signal acquisition module, and the signal acquisition module carries out the real-time acquisition of multi-frame video frames to the video image signal according to the second acquisition control signal; the image video multi-frame acquisition module according to the multi-frame video Frame transmission frame rate, verify frame loss or jitter of video image signal, and output the verification result;

The display module displays the collected static video frames or multi-frame video frames in real time.

Fig. 4 is a schematic diagram of the functional flow of the image video single-frame acquisition module in the video image evaluation module of the image acquisition and detection system embodiment 1 of the present invention; And upload it to the host computer through DLL (Dynamic Link Library); when starting the video frame acquisition module, the device information column needs to display the identification number of the device (not empty); the host computer software is limited by the performance of the FPGA acquisition card, and each acquisition upload 1080P lossless video frame time is longer, about 16s.

Fig. 5 is a schematic diagram of the functional flow of the image video multi-frame acquisition module in the video image evaluation module in embodiment 1 of the image acquisition and detection system of the present invention; , and upload to the host computer through the DLL; when starting the video frame acquisition module, the device information column needs to display the device identification number (not empty); the host computer software is limited by the performance of the FPGA acquisition card, and the 1080P lossless video uploaded each time is collected The frame time is longer, about 16s, so the multi-frame video frame acquisition time is longer, about 2 minutes; the image video multi-frame acquisition module mainly verifies the transmission frame rate of the high-definition interface video stream, and evaluates whether there is frame loss and jitter phenomena. And because the FPGA acquisition card is a circular refresh acquisition mechanism, it is necessary to acquire the start frame and the end frame, and use the elapsed time interval to calculate the corresponding frame rate.

Specifically, the video image evaluation module can include an image video single-frame acquisition module, an image video multi-frame acquisition module, and a display module. , difference positioning and result chart display. The evaluation module mainly establishes the D-SSIM model to compare and analyze the non-destructively collected image signal and the reference value, and obtain the result consistent with the subjective evaluation;

In a specific embodiment, the video image evaluation module also includes an image video analysis module;

The image and video analysis module compares and analyzes the video image signal with the reference source output by the test source module according to the preset SSIM model, and obtains the result of the comparison and analysis.

In a specific embodiment, the preset SSIM model is a D-SSIM model.

Specifically, aiming at the deficiency of SSIM, the present invention proposes an improved video objective evaluation algorithm (D-SSIM) in combination with the high resolution of the high-definition transmission interface and the chroma and saturation features of the video image. Based on SSIM, the model combines the color information of high-definition images, and constructs factors similar to the SSIM algorithm, and trains different high-definition devices through deep learning, so that the model evaluation results are accurate and the test stability is good.

Fig. 6 is a schematic diagram of the functional flow of the image video analysis module in the video image evaluation module in embodiment 1 of the image acquisition and detection system of the present invention; PSNR, MSE and SSIM all use Matlab algorithm and C# for mixed programming, so the test machine should be installed with Matlab execution package and .NET4.0; video frame images and reference frame images are 1920x1080 and 32bit static images, so PSNR, MSE and The execution time of the SSIM algorithm is limited by the image loading time, and the loading time is longer, but the execution time of the algorithm is within 1s.

In a specific embodiment, the video image evaluation module also includes an image video difference positioning module;

The image and video differential positioning module performs differential positioning processing on the video image signal, and outputs a differential positioning result.

In a specific embodiment, the test source is a 1080p, 2k4k video source.

Specifically, the test source can select 1080p and 2k4k video sources as the test source; the test source module can mainly realize: 1) as a test source output to the sink device; 2) as a reference source, provided to the image/video analysis module, for comparison.

Embodiment 1 of the image acquisition and detection system of the present invention, by using the transmission interface connected between the interface board and the liquid crystal screen in the sink device of the digital high-definition transmission interface as the boundary of the test, the interference of the liquid crystal screen on the test results is avoided, and the digital high-definition transmission is accurately measured The video transmission quality of the interface can locate defects more efficiently. While reducing the test cost, it saves a lot of time and energy of the test engineer, making the test easier and easier.

Embodiment 2 of the image acquisition and detection system of the present invention:

In order to solve the problem that the traditional technology cannot accurately measure the image quality of the digital high-definition interface, the present invention also provides an embodiment 2 of an image acquisition and detection system; FIG. 7 is a schematic diagram of the function realization structure of the embodiment 2 of the image acquisition and detection system of the present invention; Shown in Fig. 7: embodiment 2 of the present invention is through LVDS interface, and the evaluation system collects the video image signal transmitted by the digital high-definition interface of HD6M181-S-L2 TV board in real time, and through the comparative analysis module of the evaluation system, it can be fast and accurate The implementation evaluates the video image quality transmitted by the digital high-definition interface.

Among them, Fig. 8 is a schematic diagram of video image analysis test in Embodiment 2 of the image acquisition and detection system of the present invention; Fig. 9 is a schematic diagram of audio transmission quality test in Embodiment 2 of the image acquisition and detection system of the present invention; Fig. 10 is an implementation of the image acquisition and detection system of the present invention The image differential positioning schematic diagram of example 2; The invention provides a kind of connection point of LVDS and liquid crystal screen as test boundary, has avoided the influence of defects such as chromatic aberration, color cast, fuzziness of liquid crystal screen on test result, has realized digital A method for lossless collection and rapid detection of images transmitted by a high-definition interface. The system mainly consists of LVDS signal acquisition module, video image evaluation module and test source module. This method of using LVDS as the test boundary can greatly save the troubles of low efficiency of subjective test and interference of the screen to the test result. While reducing the test cost, it saves a lot of time and energy of the test engineer. The test of the image transmission quality of the high-definition transmission interface becomes simpler and easier.

Embodiment 2 of the image acquisition and detection system of the present invention uses the LVDS interface as the test boundary of the digital high-definition transmission interface, avoids the influence of the liquid crystal display screen, and accurately evaluates the video quality of the interface transmission. A high-speed FPGA is used to collect LVDS interface signals to realize real-time and non-destructive acquisition of digital high-definition transmission interface sink-end signals, which is a prerequisite for implementing an objective evaluation method.

Embodiment 1 of the image acquisition and detection method of the present invention:

Based on the technical ideas of the above embodiments of the image acquisition and detection system, and in order to solve the problem that the traditional technology cannot accurately measure the image quality of the digital high-definition interface, the present invention also provides an image acquisition and detection method embodiment 1; Figure 11 is the image of the present invention A schematic flow diagram of the first embodiment of the collection and detection method; as shown in Figure 11, the following steps may be included:

Step S110: Outputting the test source to the sink end of the digital high-definition transmission interface;

Step S110: collecting in real time the LVDS signal output by the digital high-definition transmission interface sink based on the test source;

Step S110: Perform quality detection processing on the LVDS signal to obtain an image quality detection result; the quality detection processing includes single-frame/multi-frame acquisition processing of the LVDS signal, image objective evaluation processing, difference positioning processing, and comparative analysis.

In a specific embodiment, the step of comparing and analyzing the LVDS signal may include:

According to the D-SSIM model, compare and analyze the LVDS signal and the preset reference source, and obtain the result of the comparison and analysis. The preset reference source is transmitted from the test source module to the video image evaluation module.

Embodiment 1 of the image acquisition and detection method of the present invention, by using the transmission interface connected between the interface board and the liquid crystal screen in the sink device of the digital high-definition transmission interface as the boundary of the test, the interference of the liquid crystal screen on the test results is avoided, and the digital high-definition transmission is accurately measured The video transmission quality of the interface can locate defects more efficiently. While reducing the test cost, it saves a lot of time and energy of the test engineer, making the test easier and easier.

The various technical features of the above-mentioned embodiments can be combined arbitrarily. For the sake of concise description, all possible combinations of the various technical features in the above-mentioned embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, should be considered as within the scope of this specification.

The above-mentioned embodiments only express several implementation modes of the present invention, and the descriptions thereof are relatively specific and detailed, but should not be construed as limiting the patent scope of the invention. It should be pointed out that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent for the present invention should be based on the appended claims.

Claims (10)

1. An image acquisition detection system, characterized in that, comprises a signal acquisition module connected to a digital high-definition transmission interface sink end, a test source module, and a video image evaluation connected between the signal acquisition module and the test source module module; The test source module outputs a test source to the digital high-definition transmission interface sink, and the digital high-definition transmission interface sink outputs a corresponding video image signal based on the test source; The signal acquisition module collects the video image signal in real time according to the corresponding control signal of the video image evaluation module, and sends the video image signal to the video image evaluation module; The video image evaluation module performs quality detection processing on the video image signal to obtain an image quality detection result; the quality detection processing includes single-frame/multi-frame acquisition processing of the video image signal, image objective evaluation processing, difference Sex positioning and comparative analysis. 2. image acquisition detection system according to claim 1, is characterized in that, described signal acquisition module is LVDS signal acquisition module; Described LVDS signal acquisition module is connected with the LVDS output interface of described digital high-definition transmission interface sink end; The video image signal is an LVDS signal. 3. image acquisition detection system according to claim 2, is characterized in that, described signal acquisition module comprises FPGA main control module; The FPGA main control module performs parallel acquisition and image reconstruction processing on the LVDS signal, and transmits the processed LVDS signal to the video image evaluation module. 4. The image acquisition and detection system according to claim 1, wherein the video image evaluation module comprises an image video single-frame acquisition module, an image video multi-frame acquisition module and a display module; The image video single-frame acquisition module outputs a first acquisition control signal to the signal acquisition module, and the signal acquisition module performs real-time acquisition of static video frames on the video image signal according to the first acquisition control signal; The image video multi-frame acquisition module outputs a second acquisition control signal to the signal acquisition module, and the signal acquisition module performs real-time acquisition of multi-frame video frames on the video image signal according to the second acquisition control signal; The image and video multi-frame acquisition module performs frame loss or jitter verification on the video image signal according to the transmission frame rate of the multi-frame video frame, and outputs a verification result; The display module displays the collected static video frame or the multi-frame video frame in real time. 5. The image acquisition and detection system according to claim 4, wherein the video image evaluation module also includes an image video analysis module; The image and video analysis module compares and analyzes the video image signal and the reference source output by the test source module according to the preset SSIM model, and obtains a result of the comparison and analysis. 6. The image acquisition and detection system according to claim 5, wherein the preset SSIM model is a D-SSIM model. 7. The image acquisition and detection system according to claim 4, wherein the video image evaluation module also includes an image video difference positioning module; The image and video difference positioning module performs the difference positioning processing on the video image signal, and outputs a difference positioning result. 8. The image acquisition and detection system according to any one of claims 1 to 7, wherein the test source is a 1080p, 2k4k video source. 9. A method for image acquisition and detection, comprising the following steps: Output the test source to the sink end of the digital high-definition transmission interface; Real-time acquisition of the LVDS signal output by the digital high-definition transmission interface sink based on the test source; Perform quality detection processing on the LVDS signal to obtain image quality detection results; the quality detection processing includes single-frame/multi-frame acquisition processing, image objective evaluation processing, difference positioning processing and comparative analysis of the LVDS signal. 10. The image acquisition and detection method according to claim 9, wherein the step of comparing and analyzing the LVDS signal comprises: According to the D-SSIM model, the LVDS signal is compared and analyzed with a preset reference source to obtain a result of the comparison and analysis.