CN117877399A

CN117877399A - Display equipment color depth testing system and testing method

Info

Publication number: CN117877399A
Application number: CN202410061996.0A
Authority: CN
Inventors: 毛珂; 赵霞飞; 单琳伟; 李思远; 吕勇
Original assignee: National Engineering Laboratory For Digital Tv Beijing Co ltd
Current assignee: National Engineering Laboratory For Digital Tv Beijing Co ltd
Priority date: 2024-01-16
Filing date: 2024-01-16
Publication date: 2024-04-12

Abstract

The invention provides a color depth test system and a test method of display equipment, and relates to the technical field of color depth detection of display equipment; the test method comprises the steps of constructing a test platform in a laboratory, wherein the test platform comprises a signal generator, sending a plurality of test signals with different gray levels to a display device to be tested, generating a gray level image queue by the signal generator after the test platform is constructed, outputting the gray level image queue to the display device to be tested, respectively measuring the illumination intensity displayed by the display device to be tested according to the gray level image queue by an optical measurement device to obtain brightness information corresponding to the gray level image queue, obtaining brightness and gray level relation information by a data analysis device according to the gray level image queue and the brightness information, establishing a gray level and brightness response curve according to the brightness and gray level relation information, and performing curve change analysis on the gray level and brightness response curve to obtain a color depth analysis result of the display device to be tested; the present invention provides a solution for accurate measurement of color depth of a display device.

Description

Display equipment color depth testing system and testing method

Technical Field

The invention mainly relates to the technical field of color depth detection of display equipment, in particular to a color depth test system and a color depth test method of the display equipment.

Background

Display devices (e.g., computer display terminals, televisions, mobile devices, etc.) currently on the market are diverse in color depth, covering various specifications and technical levels. Most consumer display terminals and televisions typically employ an 8bit color depth, some high-end display terminals, professional graphic design display terminals, and some advanced televisions support a 10bit color depth. In some professional and scientific applications, there are display terminals supporting a color depth of 12 bits, which is commonly used in the fields of medical imaging, scientific research, etc. The color depth test of the display terminal is performed in order to evaluate its color appearance and accuracy, ensuring that it can meet the high requirements of a specific application and user for image quality. At present, the existing schemes for testing display devices have the following defects:

(1) Subjective evaluations were performed using specialized test images. The test image contains rich colors, gradation and gray scale levels. And displaying the test image on a screen of the display terminal, detecting the modes of color depth setting, observation color accuracy, observation gray level, observation details, text and the like of the display terminal by a subjective evaluation method, and recording the test result. The subjective evaluation method has great limitation that only 8-bit and 10-bit display effects can be distinguished, and most people cannot distinguish the 10-bit and 12-bit display effects. Because of limited human perception capability, subjective measurement is easily affected by subjective errors, and human visual system perception of color and brightness may be interfered by environmental conditions, individual visual differences and other factors, and objective standard and quantitative indexes are lacking.

(2) The evaluation was performed using a color calibrator. Color calibrators are mainly used to measure and adjust the color accuracy of a display, but typically they do not directly measure the bit depth of the display. The parameters of major interest for color calibrators include brightness, saturation, hue, etc. of the color, and the accuracy of the gray scale. By adjusting the color parameters of the display, the bit depth performance of the display may be indirectly affected. Through calibration software, a user can adjust color settings to match a particular color space, thereby improving overall color performance, including perception of bit depth. Color calibrators are mainly used to measure and adjust the color accuracy of a display, but typically they do not directly measure the bit depth of the display. The bit depth of the display is typically a hardware feature that represents the number of different brightness levels that each color channel can represent. The measurement of bit depth typically requires the use of specialized test equipment, such as high precision signal generators and photometers, to obtain more accurate digital information.

Disclosure of Invention

The invention aims to solve the technical problem of providing a color depth test system and a test method for display equipment aiming at the defects in the prior art.

The technical scheme for solving the technical problems is as follows: the color depth testing system of the display equipment comprises a signal generator, optical measurement equipment and data analysis equipment, wherein the signal generator is electrically connected with the optical measurement equipment, the signal generator is electrically connected with the display equipment to be tested, and the data analysis equipment is electrically connected with the signal generator;

the signal generator is used for generating a gray level image queue and outputting the gray level image queue to the display equipment to be tested;

the optical measurement device is used for respectively measuring the illumination intensity displayed by the display device to be measured according to the gray level image queue to obtain brightness information corresponding to the gray level image queue;

the data analysis equipment is used for obtaining the brightness and gray level relation information according to the gray level image queue and the brightness information corresponding to the gray level image queue, establishing a gray level and brightness response curve according to the brightness and gray level relation information, and carrying out curve change analysis on the gray level and brightness response curve to obtain a color depth analysis result of the display equipment to be tested.

The other technical scheme for solving the technical problems is as follows: a color depth testing method of display equipment comprises the following steps:

s1, preparing a laboratory environment;

s2, after environmental preparation is completed, a test platform is built in a laboratory, wherein the test platform comprises a signal generator, optical measurement equipment and data analysis equipment, the signal generator is electrically connected with the optical measurement equipment, the signal generator is electrically connected with display equipment to be tested, and the data analysis equipment is electrically connected with the signal generator;

s3, after the test platform is built, the signal generator generates a gray level image queue, the gray level image queue is output to the display equipment to be tested, the optical measurement equipment respectively measures the illumination intensity displayed by the display equipment to be tested according to the gray level image queue to obtain brightness information corresponding to the gray level image queue, the data analysis equipment obtains brightness and gray level relation information according to the brightness information corresponding to the gray level image queue and the gray level image queue, establishes a gray level and brightness response curve according to the brightness and gray level relation information, and performs curve change analysis on the gray level and brightness response curve to obtain a color depth analysis result of the display equipment to be tested.

The beneficial effects of the invention are as follows: the method of combining the signal generator and the optical measuring device provides a scheme for accurately measuring the color depth of the display device, is favorable for obtaining reliable data, improves the accuracy of a test result, establishes and analyzes a gray level and brightness response curve through the data analysis device, is favorable for more accurate representation of the display device under various gray levels, and provides high-quality visual experience for related industries.

Drawings

FIG. 1 is a block diagram of a color depth test system of a display device according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of a color depth test system of a display device according to an embodiment of the present invention;

fig. 3 is a flow chart of a color depth testing method of a display device according to an embodiment of the present invention;

fig. 4 is a schematic diagram of gray scale versus brightness response curves according to an embodiment of the present invention.

In the drawings, the names of the components represented by the respective marks are as follows:

1. a signal generator; 2. an optical test device; 3. a data analysis device; 4. display equipment to be tested; 5. a first support frame; 6. and a second supporting frame.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments of the present invention. The components of the embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the invention, as presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

In the description of the present invention, it should also be noted that, unless explicitly stated and limited otherwise, the terms "disposed," "mounted," "connected," and "connected" should be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art.

As shown in fig. 1 and fig. 2, the color depth test system for a display device provided by the embodiment of the invention includes a signal generator 1, an optical measurement device 2 and a data analysis device 3, wherein the signal generator 1 is electrically connected with the optical measurement device 2, the signal generator 1 is electrically connected with a display device 4 to be tested, and the data analysis device 3 is electrically connected with the signal generator 1;

the signal generator 1 is used for generating a gray level image queue and outputting the gray level image queue to the display equipment 4 to be tested;

the optical measurement device 2 is configured to measure the illumination intensity displayed by the display device 4 to be measured according to the gray level image queue, so as to obtain brightness information corresponding to the gray level image queue;

the data analysis device 3 is configured to obtain luminance and gray level relation information according to the gray level image queue and luminance information corresponding to the gray level image queue, establish a gray level and luminance response curve according to the luminance and gray level relation information, and perform curve change analysis on the gray level and luminance response curve to obtain a color depth analysis result of the display device 4 to be tested.

Specifically, the signal generator is a test device capable of generating a test signal having an accurate gray level. In measuring bit depth, a signal generator is used to generate a series of gray scale images. Each gray level corresponds to a brightness level on the display. These gray levels are typically represented in digital form, e.g., from 0 (black) to 65535 (white) in the case of 16bit depths.

The optical measuring device 2 is a device for measuring the intensity of illumination. In the test, an optical measurement device is disposed on the display surface or at a standard distance from the display to measure the intensity of illumination emitted by the display at each gray level. This measurement provides a quantitative value reflecting the brightness level of the display.

By selecting different gray levels in the signal generator 1 and measuring the corresponding brightness using an optical measuring device, such as a photometer.

The data analysis device 3 may establish a relationship between brightness and gray level. This relationship forms a curve, called the luminance-gray response curve, which shows the actual luminance for each gray level. By analyzing the luminance-gray response curve, the number of different gray levels that the display can accurately display can be determined. This number is the bit depth of the display. For example, if a luminance-gray-scale response curve display is capable of accurately representing 65536 gray-scale levels with a 16bit depth, then the bit depth of the display is 16 bits.

The collected measurement data may be processed through graphical and statistical analysis to verify whether the bit depth of the display is consistent with manufacturer specifications or whether there are any potential problems such as color bands (banding) or gray level discontinuities.

In this embodiment, the manner of combining the signal generator and the optical measurement device provides accurate measurement of the color depth (bit depth) of the display device, which is conducive to obtaining reliable data, improving accuracy of test results, and establishing and analyzing gray scale and brightness response curves by the data analysis device, which is conducive to more accurate representation of the display device at various gray scale levels, and provides high quality visual experience for related industries.

Preferably, as shown in fig. 4, in the data analysis device 3, a curve change analysis is performed on the gray-scale and brightness response curves to obtain a color depth analysis result of the display device 4 to be tested, which includes:

if the gray scale and brightness response curve is in a smooth rising trend, judging that the color depth of the input video signal is lower than or equal to the color depth physically displayed on the screen;

if the gray-scale and brightness response curves have a stepwise trend, the color depth of the input video signal is determined to be higher than the color depth physically displayed on the screen.

Preferably, the data analysis device 3 further includes, after obtaining the color depth analysis result of the display device 4 to be tested:

and counting the number of different gray levels displayed by the display device 4 to be tested from the gray level and brightness response curve, and taking the counted number as the bit depth of the display device 4 to be tested.

Preferably, the color depth display device testing system further comprises a first supporting frame 5 and a second supporting frame 6, wherein the first supporting frame 5 and the second supporting frame 6 are oppositely arranged;

the first support frame 5 is of an L-shaped support structure, the signal generator 1 is arranged on a horizontal panel at the bottom of the first support frame 5, and the display equipment 4 to be tested is fixed at the top of the first support frame 5; the signal generator 1 is connected with the display equipment 4 to be tested in a line way;

the second supporting frame 6 is a triangular supporting frame, the optical measurement device 2 is fixed at the top end of the triangular supporting frame, and the distance between the optical measurement device 2 and the display device 4 to be measured is 1.5 times the height of the display device 4 to be measured. H in fig. 2 is 1.5 times the height of the display device to be measured (i.e. the display screen), i.e. 1.5 times the height of the display device to be measured is taken as the distance between the optical measuring device and the display device to be measured.

As shown in fig. 3, the color depth testing method for a display device provided by the embodiment of the invention includes the following steps:

s1, preparing a laboratory environment;

s2, after environmental preparation is completed, a test platform is built in a laboratory, wherein the test platform comprises a signal generator, optical measurement equipment and data analysis equipment, the signal generator is electrically connected with the data analysis equipment, the signal generator is electrically connected with display equipment to be tested, and the optical measurement equipment is electrically connected with the data analysis equipment;

Preferably, in S1, the preparing a laboratory environment includes:

s1.1, keeping illumination stability in a laboratory; illumination conditions: the illumination of the laboratory is kept stable and light from the outside is prevented from entering by a light shield or the like. This helps to ensure that the brightness of the display is affected by the expected illumination during the test.

S1.2, keeping the temperature in a laboratory stable; and (3) temperature control: the laboratory temperature is maintained within a stable range to prevent temperature fluctuations from affecting the performance of the display. The use of equipment that generates excessive heat is avoided to prevent temperature variations.

S1.3, controlling an external electromagnetic field in a laboratory not to interfere with the display equipment to be tested. Electromagnetic interference: the electromagnetic interference source is controlled in the laboratory to prevent the influence of external electromagnetic fields on the test equipment. Ensuring that the test environment meets the electromagnetic compatibility standard.

Preferably, in S2, the process of building a test platform in a laboratory includes:

the first support frame and the second support frame are oppositely arranged;

placing the signal generator on a horizontal panel at the bottom of the first support frame, and fixing the display equipment to be tested on the top of the first support frame;

and fixing the optical measurement equipment at the top end of the second supporting frame, and placing the optical measurement equipment at a distance which is 1.5 times the height of the display equipment to be measured.

Preferably, in S2, the process of building a test platform in a laboratory further includes:

calibrating the color mode of the display equipment to be tested;

and calibrating the brightness measurement mode of the optical measurement device.

Specifically, a display device to be tested (i.e., a display) is prepared: ensure that the display for testing is in proper operation and complete the necessary preheating.

1) And (3) stabilizing a power supply: a stable power supply is used to ensure that the display does not experience unstable performance due to power supply fluctuations during testing.

2) Calibration check: before the test starts, it is confirmed that the display has been substantially calibrated and that the calibration settings are correct, ensuring that the display is in a standard color mode.

Individual device connection and calibration: the signal generator and the optical measuring device are connected and the necessary calibration steps are performed.

1) The signal generator is connected with: the high precision signal generator is connected to the display. The signal generator is adapted to generate a series of test signals of different gray levels. Ensuring that the output of the signal generator meets the input requirements of the display.

2) Optical measurement device (i.e., photometer) calibration: the photometer is calibrated to ensure that it accurately measures the brightness of the display. Calibration should be performed before the test begins and periodically verified when needed. The optical test device was placed at a distance of 1.5 times the height of the display screen or attached to the display using a sleeve to measure the brightness at each gray level.

In the above embodiments, the test laboratory is ensured to have proper environmental conditions to reduce the interference of external factors on the test results.

Preferably, in the step S3, the process of performing curve change analysis on the gray scale and brightness response curve to obtain a color depth analysis result of the display device to be tested includes:

Preferably, after obtaining the color depth analysis result of the display device to be tested, the method further comprises:

and counting the number of different gray levels displayed by the display equipment to be tested from the gray level and brightness response curve, and taking the counted number as the bit depth of the display equipment to be tested.

The method comprises the following specific steps:

1. and (3) generating a test image: the signal generator is arranged to generate a test image covering the entire brightness range.

1) Gray level selection: a series of gray levels are chosen to ensure that the test image can cover all possible brightnesses from darkest black to brightest white.

2. Brightness measurement: brightness measurements were made using an optical test device.

1) For each generated gray level, a corresponding luminance is measured using a photometer. It is ensured that the brightness value of each gray level is recorded.

3. Data analysis of curve change of gray scale and brightness response curve:

1) And comparing the measured brightness value with the corresponding gray level to establish a brightness-gray level relation. This will constitute a "gray-brightness variation curve".

2) Theoretically, if the "gray-brightness variation curve" rises smoothly, there is no stepwise rise, which means that the color depth of the input video signal is lower than or equal to the color depth that the screen can physically display; if the gray-brightness change curve has obvious brightness value stepwise change, the color depth of the input video signal is higher than the color depth which can be displayed physically on the screen.

3) Bit depth calculation: by analyzing the luminance-gray response curve, the number of different gray levels that the display can accurately display is determined. It will be appreciated that this number is the bit depth of the display.

The invention has the advantages that:

1) The method for establishing the brightness-gray scale relation curve comprises the following steps: the present solution proposes a method of determining the bit depth by establishing a luminance-gray scale relationship. This approach involves unique data analysis and processing steps that help to improve the accuracy of the bit depth measurement.

2) Innovation of data analysis and bit depth calculation: the bit depth is calculated by data analysis, which makes it original in the field of bit depth measurement.

3) Generating a test image of the whole coverage brightness range: by arranging the signal generator to generate a test image for the whole brightness range, the scheme ensures a full assessment of the display performance. The method is a unique test design, and the display performance under each gray level can be more comprehensively known.

4) Use of high precision test equipment in combination: a high precision signal generator is used in conjunction with an optical measurement device (i.e., photometer) to measure the display bit depth. This combination is a unique feature by which the scheme can provide more accurate, reliable bit depth measurements.

It is noted that relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

The foregoing description of the preferred embodiments of the invention is not intended to limit the invention to the precise form disclosed, and any such modifications, equivalents, and alternatives falling within the spirit and scope of the invention are intended to be included within the scope of the invention.

Claims

1. The color depth testing system of the display device is characterized by comprising a signal generator (1), an optical measurement device (2) and a data analysis device (3), wherein the signal generator (1) is electrically connected with the display device (4) to be tested, the data analysis device (3) is electrically connected with the signal generator (1), and the data analysis device (3) is electrically connected with the optical measurement device (2);

the signal generator (1) is used for generating a gray level image queue and outputting the gray level image queue to the display equipment (4) to be tested;

the optical measurement device (2) is configured to measure the illumination intensity displayed by the display device (4) to be measured according to the gray level image queue, so as to obtain brightness information corresponding to the gray level image queue;

the data analysis device (3) is used for obtaining brightness and gray level relation information according to the gray level image queue and brightness information corresponding to the gray level image queue, establishing a gray level and brightness response curve according to the brightness and gray level relation information, and performing curve change analysis on the gray level and brightness response curve to obtain a color depth analysis result of the display device (4) to be tested.

2. The color depth test system of a display device according to claim 1, wherein the data analysis device (3) performs curve change analysis on the gray scale and brightness response curve to obtain a color depth analysis result of the display device (4) to be tested, and the method comprises:

3. The color depth test system of a display device according to claim 1, wherein the data analysis device (3) further comprises, after obtaining the color depth analysis result of the display device (4) to be tested:

and counting the number of different gray levels displayed by the display equipment (4) to be tested from the gray level and brightness response curve, and taking the counted number as the bit depth of the display equipment (4) to be tested.

4. The display device color depth test system according to claim 1, further comprising a first support (5) and a second support (6), the first support (5) and the second support (6) being disposed opposite each other;

the first support frame (5) is of an L-shaped support structure, the signal generator (1) is arranged on a horizontal panel at the bottom of the first support frame (5), and the display equipment (4) to be tested is fixed at the top of the first support frame (5); the signal generator (1) is in line connection with the display equipment (4) to be tested;

the second support frame (6) is a triangular support frame, the optical measurement device (2) is fixed at the top end of the triangular support frame, and the distance between the optical measurement device (2) and the display device (4) to be measured is 1.5 times of the height of the display device (4) to be measured.

5. The color depth testing method for the display device is characterized by comprising the following steps of:

s1, preparing a laboratory environment;

6. The method for testing color depth of display device according to claim 5, wherein in S1, the laboratory environment preparation comprises:

the illumination stability in the laboratory is kept;

keeping the temperature in the laboratory stable;

the control laboratory external electromagnetic field does not interfere with the display device to be tested.

7. The method for testing the color depth of the display device according to claim 5, wherein in S2, the process of building the test platform in the laboratory includes:

the first support frame and the second support frame are oppositely arranged;

8. The method for testing the color depth of a display device according to claim 7, wherein in S2, the process of building the test platform in the laboratory further comprises:

calibrating the color mode of the display equipment to be tested;

9. The method for testing color depth of display device according to claim 5, wherein in S3, the process of performing curve change analysis on the gray-scale and brightness response curves to obtain the color depth analysis result of the display device to be tested includes:

10. The method for testing color depth of display device according to claim 5, further comprising, after obtaining the analysis result of color depth of display device to be tested: