KR20050007721A - Method and Apparutus for testing image quality - Google Patents

Abstract

PURPOSE: A system and a method for testing quality of an image signal are provided to reduce hours and man power required for a test and improve reliability in the test by automatizing the test of the quality thereof in a produced AV(Audio and Video) device. CONSTITUTION: A storage media(113) applies an image signal of a test pattern including an RGB(Red Green Blue) signal with a predetermined level to an image signal record reproduction unit. An RGB extraction part(115) extracts an RGB signal included in each horizontal line from the image signal of the test pattern. An average error value calculation part(127) calculates an average error value on a basis of the number of times an error arises in the RGB signal and error values which are larger than an upper bound and less than a lower bound. A color comparison part(128) compares the average error value with a reference value by each color signal. A display part(122) shows a comparison result of the color comparison part.

Description

Image signal quality test system and test method {Method and Apparutus for testing image quality}

The present invention relates to a test system and method for testing the quality of a video signal output from a video signal reproducing and recording apparatus, and in particular to the automatic test of the quality of the video signal output from the video signal reproducing and recording apparatus. The present invention relates to a quality test system and method for video signals that can reduce the time and manpower required.

In general, AV (Audio and Video) devices such as video, CD playback devices and DVD players are tested to test for abnormality and quality of the product after production is completed, and the products that have passed the test among the produced products Only sold. In general, such a test is performed by observing a screen directly reproduced by an inspector. Since a tester is a human, a test may not always be performed at a predetermined level, and a test takes a long time. Furthermore, if it is necessary to test the quality of the reproduced video signal beyond the test for the normal operation of the AV device, additional test time and manpower is required.

1 is a conceptual diagram illustrating a conventional method for testing video signal quality.

As shown, when testing the AV device, an optical medium (not shown) such as a DVD having a test pattern is loaded into the AV device 10, and the loaded optical media is played back to monitor the loaded device. Display on. The inspector determines whether the AV device 10 is normal or bad by looking at the reproduced video signal to determine whether the AV device 10 can reproduce a level of image quality suitable for sale. In this case, the criterion is entirely determined by the visual inspection and judgment of the inspector. If the inspector feels fatigue during long time work, the test criterion may be different. When a plurality of AV devices are to be tested, the time allocated to each AV device test may be As a result, there is a problem that the reliability of the test is lowered.

The present invention has been made to solve the above problems, an object of the present invention, when testing the video signal quality of the produced AV device, by automating it to reduce the time and manpower required for the test, and improve the reliability of the test The height is to provide a video signal quality test system and test method.

1 is a conceptual diagram illustrating a conventional method for testing video signal quality;

2 is a block diagram according to a preferred embodiment of the image signal quality test system according to the present invention;

3 is a detailed block diagram of the average error value calculating unit and the comparing unit of FIG. 2;

4A to 4C are diagrams showing a screen on which waveforms of R, G, and B signals, an upper limit of an error value, and a lower limit of an error value are displayed;

5 is a conceptual diagram illustrating a method of calculating an average error value of an R signal average error value calculation unit;

6 is a flowchart of a preferred embodiment of a video signal quality test method according to the present invention.

* Description of the symbols for the main parts of the drawings *

100: video signal quality inspection device 110: image caption board

113: frame memory 115: RGB extraction unit

120: data processing unit 127: average error value calculation unit

127: average error value calculation unit 128: comparison unit

According to the present invention, in the video signal analysis system for analyzing the R, G, B signals output from the video signal recording and reproducing apparatus having a video signal reproducing function, loading into the video signal recording and reproducing apparatus A storage medium for applying a video signal for a test pattern including a predetermined level of R, G, and B signals to the video signal recording and reproducing apparatus, R provided in each horizontal line from the video signal for the test pattern, RGB extraction unit for extracting G and B signals, the sum of the number of errors generated from the R, G, and B signals extracted for each horizontal line by the RGB extraction unit, and the sum of error values exceeding and exceeding predetermined upper and lower limits. An average error value calculating unit for calculating an average error value based on the control unit, a color comparison unit comparing the average error value with a preset reference value for each color signal, and a display device for displaying a comparison result of the comparison unit; Is achieved.

The average error value calculator is configured to calculate a first average error value for the R signal based on the sum of the number of errors generated in the R signal output from the RGB extractor and the error value corresponding to each number. A second average error value calculator for calculating a second average error value for the G signal based on the sum of the number of errors generated in the G signal output from the RGB calculator and the error value corresponding to each number; And a third average error value calculating unit calculating a third average error value for the B signal based on the sum of the number of errors generated in the B signal output from the RGB extracting unit and the error value corresponding to each number. .

The color comparison unit may include a first comparison unit comparing the first average error value and the reference value, a second comparison unit comparing the second average error value and the reference value, and the third average error value and the reference value. The third comparison part to compare is included.

Preferably, the first comparison unit to the third comparison unit determines that the video signal recording and reproducing apparatus is defective when the comparison result of any one of the first comparison unit and the third comparison unit exceeds the reference value. do.

According to the present invention, in the method for analyzing the R, G, B signals output from the video signal recording and reproducing apparatus having a video signal reproducing function, reproducing a test pattern including the R, G, B signals Extracting R, G, and B signals for each horizontal line from the reproduced test pattern; and errors exceeding and exceeding a predetermined number of errors generated from the extracted R, G, and B signals and predetermined upper and lower limits. Calculating an average error value based on the sum of the values and comparing the calculated average error value with a preset reference value to determine whether the video signal recording and reproducing apparatus is defective.

The calculating of the average error value may include calculating a first average error value for the R signal based on a sum of an error number generated in the extracted R signal and an error value corresponding to each number, and the extraction. Calculating a second average error value for the G signal based on the sum of the number of errors generated in the generated G signal and the error value corresponding to the number of times, and the number of errors generated in the extracted B signal, And calculating a third average error value for the B signal based on the sum of the error values corresponding to the number of times.

Comparing the calculated average error value with a predetermined reference value, comparing the first average error value and the reference value, comparing the second average error value and the reference value, and the third average error Preferably, the method comprises comparing a value with the reference value.

The comparing of the calculated average error value with a preset reference value may include: comparing the first average error value to the third average error value with the reference value, and among the first average error value and the third average error value. When at least one exceeds the reference value, it is preferable to judge the video signal recording and reproducing apparatus as a failure.

Hereinafter, the present invention will be described in detail with reference to the drawings.

Figure 2 shows a block diagram according to an embodiment of a video signal quality test system according to the present invention. The illustrated video signal quality test system includes a plurality of inspection apparatuses 100, 100-2 and 100-3, a database server 200, and a plurality of management apparatuses 300, 300-2 and 300-3. It is possible to communicate with the communication network 400.

The plurality of inspection apparatuses 100, 100-2, and 100-3 perform a function of inspecting the quality of the image signal of the A / V device produced, and the types of inspections performed by the respective inspection apparatuses may be different. In FIG. 2, the video signal quality test system includes a video signal quality inspection apparatus 100 of an A / V apparatus, a video output performance inspection apparatus 100-2 of an A / V apparatus, and an audio output performance inspection of an A / V apparatus. Although shown as including the device 100-3, it is also possible to include other inspection devices. A detailed description of the video signal quality inspection apparatus 100 of the A / V device will be described later.

The database server 200 receives and stores the test results from the plurality of test apparatuses 100, 100-2, and 100-3, and in particular, when it is determined that an error or a bad result is obtained by checking the performance of the A / V device. This information is recorded in detail, in order to provide developers and producers with information for analyzing errors and defects of the produced A / V equipment. In addition, the database server 200 calculates and records statistical values, average values, graphs, and the like based on the inspection results.

The plurality of management apparatuses 300, 300-2, and 300-3 control and manage the plurality of inspection apparatuses 100, 100-2, and 100-3, and the inspection apparatuses 100, 100-2, and 100-. 3) is a device for searching the test results. The plurality of management devices 300, 300-2, and 300-3 may be configured as an inspection result management device 300, an inspection item / order management device 300-2, and an inspection condition management device 300-3. .

In FIG. 2, the inspection result management apparatus 300 includes a user command unit 310, a search / processing unit 320, and a monitor 330. In the case of the inspection result management apparatus 300, when a user (administrator) selects and inputs any one of the plurality of inspection apparatuses 100, 100-2, and 100-3 through the user command unit 310, the search / processing unit 320 retrieves and extracts only data related to the inspection result of the inspection apparatus selected by the user among the data stored in the database server 200, and displays the data on the monitor 330 to provide the desired inspection result to the user. In addition, when there is a separate request for separate statistical data from the user command unit 310, the search / processing unit 320 detects statistics, average values, graphs, etc. for the test results stored in the database server 200. Thus, the monitor 330 can be displayed in the form of a report.

The user may designate the inspection item and the inspection order through the inspection item / order management device 300-2. For example, in the case of the A / V device, the audio output performance test and the video output performance test may be performed such as a video output performance and a video signal quality test. In the user, the inspection item / order management device 300-2 may specify the inspection item. Therefore, in the case of the audio device among the A / V devices, it is not necessary to check the video output performance, so that only the audio output performance can be checked. In addition, the user may designate the order in which the inspection apparatus performs the inspection, and may also designate the inspection apparatus to be performed at the same time.

The user may designate the inspection condition through the inspection condition management apparatus 300-3. The inspection apparatus receives a specific signal output from the produced A / V equipment, calculates data necessary for inspection through the signal, and determines whether the performance of the A / V equipment is good or bad based on the data. Means the condition on which the determination is based. The inspection conditions are actually designated and changed through a user interface provided in the inspection apparatus that performs the inspection of the A / V apparatus, but the inspection condition management apparatus 300-3 allows the user to input the inspection conditions. When the inspection device is located in the production line, it is to allow the inspection condition of the inspection device to be entered in the office, which is a remote place from the production line.

Meanwhile, the inspection item / order and inspection conditions specified by the user through the inspection item / order management device 300-2 and the inspection condition management device 300-3 are transmitted to the database server 200 and stored. 100, 100-2, and 100-3 receive information corresponding to themselves and refer to the A / V device when checking the A / V device.

Hereinafter, the video signal quality inspection apparatus 100 of the A / V device will be described in detail.

Referring to FIG. 2, the optical media 510 stores a preset test pattern. The test pattern is an image signal including R (Red), G (Green), and B (Blue) three primary colors, and when reproduced, R, G, and B primary colors are displayed in the vertical direction of the screen (not shown). At this time, since the R, G, and B signals each have an 8-bit data size, each of the R, G, and B signals can represent 0 to 255 levels. In the present embodiment, it is assumed that the R, G, and B signals constituting the test pattern have 200 levels, respectively.

The A / V device 520 reproduces and outputs a test pattern stored in the optical media 510 when the optical media 510 is loaded. Here, the A / V device 520 is a test object for testing whether the test pattern can be normally reproduced.

The image signal quality inspection apparatus 100 includes an image caption board 110 and a data processor 120, and the image caption board 110 includes a sampler 111, a frame memory 113, and an RGB extractor 115. It consists of. The sampler 111 samples a video signal of a test pattern reproduced and output from the A / V device 520 at a predetermined frequency, converts the image signal into a digital signal, and then transmits the converted video signal to the frame memory 113, and then, the frame memory 113. Stores the digital video signal received from the sampler 111 in units of frames.

The RGB extractor 115 extracts R, G, and B signals for each horizontal line from the test pattern stored in the frame memory 113, and transmits the signals to the data processor 120. If the video signal output from the A / V device 520 has a resolution of 640 × 480, the RGB extractor 115 extracts the R, G, and B signals included in each 480 line for each horizontal line. do.

The data processor 120 includes a data bus 121, a display 122, a user interface 123, a central processor 124, an average error value calculator 127, and a comparator 128.

The average error value calculator 127 calculates an average error value based on the number of errors generated from the R, G, and B signals extracted for each line and the sum of the error values. Here, it is determined that an error has occurred when each of the extracted R, G, and B signals exceeds 200 levels. At this time, since the maximum value of the RGB signal is 255 levels as described above, the maximum value of the error value is 55 (255 levels-200 levels).

The comparator 128 compares the average error value calculated by the average error value calculator 127 with the preset average reference value ref to determine whether the A / V device 520 is defective. Accordingly, when the average error value calculated by the average error value calculation unit 127 exceeds the average reference value ref, the A / V device 520 is determined to be defective. Otherwise, the A / V device 520 is determined. Will be judged to be normal.

When the comparison unit 128 outputs the comparison result to the central processing unit 124, the central processing unit 124 controls the test result to be displayed on the display unit 122.

FIG. 3 is a detailed block conceptual diagram of the average error value calculating unit 127 and the comparing unit 128 in FIG. 2. In FIG. 3, the RGB extracting unit 113, the data bus 121, and the central processing unit 124 are shown together for convenience of understanding. The average error value calculator 127 includes an R signal average error value calculator 127-1, a G signal average error value calculator 127-2, and a B signal average error value calculator 127-3. .

The R signal average error value calculator 127-1 is extracted from the RGB extractor 115 and is based on the sum of the number of errors generated in the R signal transmitted through the data bus 121 and the sum of the generated error values. Calculate the signal average error value. For example, if three errors occur in the R signal, and the sum of the error values generated is 150, the R signal average error value is 50. At this time, if the average reference value ref applied to the comparator 128 is set to 40, the A / V device 520 is determined to be defective. In this case, to increase the test criterion of the A / V device 520, the average reference value ref may be set small, and in the opposite case, the average reference value ref may be set large. On the other hand, the R signal average error value calculator 127-1 has two reference values, RH and RL, for determining the upper and lower limits of the error value. As described above, since the level of each of the R, G, and B signals is set to 200 levels, the sum of the error values is calculated by applying the same to the higher or lower error values. For example, when the upper limit (RH) of the error value is set to 210 and the lower limit (RL) of the error value is set to 190, the level of the R signal is higher than the upper limit (RH) of the reference value or lower than the lower limit (RL) of the average reference value. The error value is obtained by averaging the sum of the error values and calculating the average error value of the R signal.

Since the operations of the G signal average error value calculator 127-2 and the B signal average error value calculator 127-3 operate in the same manner as the R signal average error value calculator 127-1 described above, Omit it.

The comparator 128 includes an R signal comparator 128-1, a G signal comparator 128-2, and a B signal comparator 128-3. The R signal comparison unit 128-1 compares the R signal average error value calculated by the R signal average error value calculator 127-1 with the average reference value ref to determine whether the A / V device 520 is normal or defective. Determine whether or not. The G signal comparison unit 128-2 compares the G signal average error value calculated by the G signal average error value calculator 127-2 with the average reference value ref to determine whether the AV device 520 is normal or defective. To judge. Similarly, the B signal comparison unit 128-3 compares the B signal average error value calculated by the B signal average error value calculator 127-3 with the average reference value ref to normal the A / V device 520. Judge for defects. The comparison results of the respective R, G, and B signal comparison units 128-1 to 128-3 are output to the central processing unit 124, and among the R, G, and B signal comparison units 128-1 to 128-3. If any one outputs a comparison result as a failure, the central processing unit 124 notifies the inspector by causing the inspection result to be displayed on the display 122 as a failure. Therefore, when a plurality of video signal quality inspection apparatus 100 is provided, the inspector can test several A / V apparatus 520 at the same time, only the A / V apparatus 520 in which the inspection result is displayed as defective. Since it is necessary to check, the time required for the inspection of the produced A / V device 520 can be reduced.

In addition to the waveforms of the R, G, and B signals, the display unit 122 may display the waveforms of the upper limit error values (RH, GH, BH) and the lower limit values (RL, GL, BL) of the error values. 4A to 4C show the screens displayed on the display unit 122. 4A is a view showing a screen in which the waveform of the R signal and the waveforms of the RH and RL are displayed on the display unit 122. FIG. 4B is a screen in which the waveform of the G signal and the waveforms of the GH and GL are displayed on the display unit 122. 4C is a diagram illustrating a screen in which the waveform of the B signal and the waveforms of the BH and BL are displayed on the display unit 122.

Referring to FIG. 2, the inspector sets, through the user interface unit 123, an average reference value ref, an upper limit of the error value (RH, GH, BH), a lower limit of the error value (RL, GL, BL), and the like. You can change it.

5 is a conceptual diagram illustrating a method of calculating an average error value of the R signal average error value calculation unit.

As shown, it can be seen that an error occurred in three R signals P2, P3, and P5 among the n R signals P1 to Pn. Here, the upper limit RH of the error value of the R signal average error value calculator 127-1 is set to 210 levels. Accordingly, the error values of the R signals P2, P3, and P5 exceeding the upper limit RH of the reference value are 20, 20, and 50, respectively, and their sum is 90. Dividing this by 3, the number of error occurrences, the average error value of the R signal is 30. At this time, if the average reference value ref of the R signal comparator 161 is 40, it is determined that the R signal is normal. If the average reference value ref is 20, the R signal is determined to be bad. Here, the average reference value ref may be lowered to increase the quality level of the A / V device 520 produced. As such, by quantifying the number of error occurrences and error values of the R, G, and B signals, when the produced A / V device 520 is tested, the reliability of the test can be improved through quantified criteria.

6 is a flowchart of a preferred embodiment of a video signal quality test method according to the present invention.

First, the A / V device 520 reproduces an image signal having a predetermined test pattern (S800). The reproduced test pattern is an image signal including R (Red), G (Green), and B (Blue) primary colors, and when reproduced, R, G, and B primary colors are displayed in the vertical direction of the screen (not shown). In this case, since the R, G, and B signals each have an 8-bit data size, each of the R, G, and B signals can be represented with 0 to 255 levels. In the present embodiment, it is assumed that the R, G, and B signals constituting the test pattern have 200 levels, respectively. Next, the video signal reproduced and output by the A / V device 520 is converted into a digital signal, and then R, G, and B signals are extracted for each horizontal line (S810). Next, an average error value of each of the extracted R, G, and B signals is calculated. The average error value is calculated based on the sum of the number of errors generated in the R, G, and B signals and the error value exceeding the reference value (S820). The error values are referred to as R signal average error values, G signal average error values, and B signal average error values, respectively. Next, the R signal average error value calculated as described above is compared with a preset average reference value ref (S830). As a result of the comparison, if the R signal average error value is larger than the average reference value ref, the A / V device 520 is determined to be defective (S840), otherwise, the average reference value ref and the G signal average error value are compared (S850). ). As a result of the comparison, when the G signal average error value is larger than the preset average reference value ref, the A / V device 520 is determined to be bad, otherwise the average reference value ref is compared with the B signal average error value (S860). . As a result of the comparison, when the B signal average error value is larger than the preset average reference value ref, the A / V device 520 is determined to be bad, otherwise the A / V device 520 is determined to be normal (S870). By such a determination method, it is possible to reduce the time and manpower required for the test and increase the reliability of the test by automating the test process, away from the method of visually observing the test pattern through the monitor by the conventional manual monitor.

As described above, the present invention can automatically test according to the quantified criteria when testing the image of the AV device, it is possible to reduce the time required to test the quality of the video signal output from the produced AV device, The reliability of the test also increases.

Although the preferred embodiments of the present invention have been illustrated and described above, the present invention is not limited to the specific embodiments described above, and the present invention is not limited to the specific embodiments of the present invention without departing from the spirit of the present invention as claimed in the claims. Anyone of ordinary skill in the art can make various modifications, as well as such changes are within the scope of the claims.

Claims (8)

In the video signal analysis system for analyzing the R, G, B signals output from the video signal recording and playback apparatus having a video signal reproduction function, A storage medium which, when loaded into the video signal recording and reproducing apparatus, applies a video signal for a test pattern including a predetermined level of R, G and B signals to the video signal recording and reproducing apparatus; An RGB extracting unit for extracting R, G, and B signals provided in each horizontal line from the image signal for the test pattern; An average error value for calculating an average error value based on the sum of the number of errors generated in the R, G, and B signals extracted by each horizontal line from the RGB extracting unit, and an error value exceeding or exceeding a predetermined upper limit and lower limit; A calculator; A color comparison unit comparing the average error value with a preset reference value for each color signal; And And a display device for displaying a comparison result of the comparison unit. The method of claim 1, The average error value calculation unit, A first average error value calculating unit calculating a first average error value for the R signal based on the sum of the number of errors generated in the R signal output from the RGB extraction unit and the error value corresponding to each number; A second average error value calculating unit calculating a second average error value for the G signal based on the sum of the number of errors generated in the G signal output from the RGB extraction unit and the error value corresponding to each number; And And a third average error value calculator configured to calculate a third average error value for the B signal based on the sum of the number of errors generated in the B signal output from the RGB extractor and the error value corresponding to each number. Image signal quality test system, characterized in that. The method of claim 2, The color comparison unit, A first comparing unit comparing the first average error value with the reference value; A second comparing unit comparing the second average error value with the reference value; And And a third comparing unit comparing the third average error value with the reference value. The method of claim 3, The first comparison unit to the third comparison unit, And the video signal recording and reproducing apparatus is judged to be defective when a comparison result of any one of the first comparison section and the third comparison section exceeds the reference value. In the method for analyzing the R, G, B signals output from the video signal recording and playback apparatus having a video signal reproduction function, Reproducing a test pattern including R, G, and B signals; Extracting R, G, and B signals for each horizontal line from the reproduced test pattern; Calculating an average error value based on a sum of an error number generated in the extracted R, G, and B signals and an error value that exceeds and falls below a predetermined upper limit value and a lower limit value; And And determining whether the image signal recording and reproducing apparatus is defective by comparing the calculated average error value with a preset reference value. The method of claim 5, The step of calculating the average error value, Calculating a first average error value for the R signal based on a sum of an error number generated in the extracted R signal and an error value corresponding to each number; Calculating a second average error value for the G signal based on the sum of the number of errors generated in the extracted G signal and an error value corresponding to the number of times; And And calculating a third average error value for the B signal based on the sum of the number of errors generated in the extracted B signal and an error value corresponding to each number of times. . The method of claim 5, Comparing the calculated average error value with a predetermined reference value, Comparing the first average error value with the reference value; Comparing the second average error value with the reference value; And And comparing the third average error value with the reference value. The method of claim 7, wherein Comparing the calculated average error value with a predetermined reference value, When the at least one of the first average error value and the third average error value exceeds the reference value, the video signal recording and reproducing apparatus Image signal quality test method, characterized in that judged as defective.