JPH02296489A - Test pattern generating method - Google Patents

Abstract

PURPOSE:To generate a test pattern chart without requiring the special technology by converting picture information of a picture on a display device into gradation information and converting it into a data form suitable for the picture output system applying picture quality evaluation. CONSTITUTION:Pattern information of an original chart generated on a display device 24 is read as a digital data for each picture element in the order of scanning line according to a control program by a central processing unit 10, converted into gradation information according to a gradation conversion table and filed as a picture element data in the time series. Then the central processing unit converts the filed picture element into a data format in matching with the signal form decided by the applied picture output system such as subsample (thinning of picture element data), time division multiplex or addition of a synchronizing signal according to the control program, stores the result tentatively to a storage device such as a floppy disk 16 and the data is sent to a semiconductor memory generating device 2 via an RS-232C interface 28.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a test pattern generation method, and particularly to a test pattern generation method for creating a test chart for evaluating the image quality of an image output system such as a digital television system.

(Prior Art) As is well known, adjustments and performance evaluations of television equipment and systems are performed using various test charts in which test patterns are designed. For example, ``Evaluation of television systems using rlTE test charts'' is published in ``Television Image Evaluation Technique'', pages 121 to 150, edited by the Television Society of Japan and published by Corona Publishing. Here, characteristics evaluation of an imaging device using various charts and utilization of charts for evaluating received image quality are shown.

After creating the design of such a test chart,
For example, the image is output using optical means such as a flying spot scanner or a television camera. Note that the test pattern is often composed of a black and white screen, such as a resolution chart, for example. For this reason, the test pattern discussed below as a conventional technique will be explained on the assumption that the test pattern is composed of a black and white screen in order to facilitate understanding, but the basic principle is the same for a color test pattern.

As clearly stated in the above-mentioned cited document, the objects used as the test bags 1 to 1 are usually print media.

For this reason, conventionally, a test pattern chart created on a print medium is converted into an image signal using an imaging device such as a television camera or an image reading device such as a flying spot scanner. This image signal is then subjected to predetermined signal processing to be suitable for, for example, a television system, and reproduced on a monitor system as an image similar to the subject. This playback screen is used to evaluate or adjust the television system.

On the other hand, as is well known, the digitalization technology in television technology in recent years has been remarkable, and for example, many image processing systems are now using digital methods. FIG. 2 shows a conventional technique for generating a test pattern using such a digital method. A conventional technique of a test pattern generation method will be explained using the same figure.

The test pattern chart 5 created as a print medium is read by, for example, an imaging device 50 and converted into an analog image signal 7 This imaging device 50
The image signal obtained is sampled by the A/D converter 52 and converted into a digital signal. moreover,
The image signal converted into a digital signal is sent to an image processing system 54
The image is processed into the signal format specified by the system.
It is temporarily stored in the memory 56 as pixel data.

The pixel data written here is sent to a semiconductor memory generation device 58, and is stored by this generation device 58 in a semiconductor memory element 3 such as a read-only memory (ROM1).

The pixel data stored in the memory element 3 is restored to the original signal by the data reading section 30, the D/A converting section 32, and the image processing system 34, and is reproduced as a test pattern by the monitor system 36. In this conventional technique, an image signal of a test pattern chart is recorded in the semiconductor memory element 3.
By overlapping them, test patterns can be generated on the monitor system 36 at any time. Therefore, for example, evaluation or adjustment of the television system can be easily performed.

(Problems to be Solved by the Invention) However, in such conventional techniques, the process of storing image data of a test pattern chart in a storage device such as a semiconductor memory element is complicated. In other words, the conventional method required a lot of time and effort to create a test pattern chart using photolithography, photograph the created test pattern chart using optical means, and prepare hardware for A/D conversion. In particular, creating a test pattern chart requires special technology in a specialized field.Furthermore, when photographing a test pattern chart with an imaging device, it requires complicated and specialized skills, such as preparing the photographing environment. There was also the problem that it involved a lot of work.

The present invention eliminates the drawbacks of the conventional technology in the stage of creating a test pattern chart and photographing an optical device, and provides a test pattern generation method that does not require special technology or work such as preparing a photographing environment. The purpose is to provide.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention provides a test pattern generation method for creating a test chart for evaluating the image quality of a single image output system. When displaying an image, a computer stores the image information to be displayed in the internal memory for screen display, creates and displays an arbitrary image of a button on the display by a program, and when the image is displayed on the display, the computer stores the image information to be displayed. By converting the image information of the image on the display stored in the internal display memory into single gradation information and converting it into a data format suitable for the image output system that evaluates the image quality, it can be used as a test pattern for the image output system. Create image information to use.

(Function) According to the present invention, when an image created by a computer program is displayed on a display, the image information stored in the internal memory of the screen is converted into gradation information and one 6. Then, the converted image information is transferred from the computer to a semiconductor memory generation device, and the semiconductor memory generation device transfers this image information to a semiconductor memory element. The image information stored in the semiconductor memory element is read out from here and subjected to a predetermined signal conversion process, thereby creating an image output system in which a similar image of the image displayed on the computer display is used to evaluate the image quality. is played.

(Example) Next, an example of the test pattern generation method according to the present invention will be described in detail with reference to the accompanying drawings.

Referring to FIG. 1, a block diagram of an embodiment of the test pattern generation method according to the present invention is shown. The personal computer 1 is hardware that is activated by a test pattern generation program to create image information that becomes the original chart of this test pattern.

The personal computer l has a floppy disk (F
It is a general-purpose personal computer with a digital color display function and a built-in DDI controller 14.
4 and external devices such as a keyboard 20 are connected.

Central processing unit + (:PUl 10 is internal bus 1.00
through the main memory 12, floppy disk drive (FDDI controller 14, keyboard interface 18, CRT controller, controller 22 and RS-
This is a control unit of the personal computer main body that controls and manages the 2'32C ink face 28 and the like. Main memo month 2 is internal memory that can be directly accessed by the processing unit IO. In this embodiment, the main memory 12 stores a control program for generating an original chart of a test pattern, that is, a test pattern generation program. In this embodiment, the test pattern generation program is programmed in a high-level language such as a basic language that can be displayed on a screen relatively easily and has excellent program productivity.

The floppy disk drive controller 14 is an EB
This is a control device that controls reading/writing to the floppy disk 16, which is a digital storage medium. In this embodiment, the disk 16 is a storage device that temporarily stores image information converted into a file as test pattern final data, and stores test pattern generation programs and the like. In this embodiment, the file image information, test pattern generation program, etc. are written on the floppy disk 16, but these may of course be stored on an external storage device such as a hard disk.

The keyboard interface 18 is an interface unit that notifies the central processing unit 10 of information input by the operator of the computer 1 via the keyboard 20. During the test pattern generation process, the operator can change the contents of the test pattern generation program using the keyboard 20, and can generate any desired test pattern.

The CRT controller 22 is a control unit that controls image display on a CRT display 24 capable of color display.

A video RA&126, which is a fresh memory, is connected to this controller 22, and pixel data to be displayed on the CRT display 24 is stored here for each display color. C
The RT display 24 is a color display device with a pixel density of 640 x 480 that can be connected and controlled by an ordinary personal computer. Although a display having such a pixel density was used in this embodiment, the pixel density of the CRT display 24 is not limited to this in the present invention, of course.

The R3-232G interface 28 is connected to the semiconductor memory generation device 2, which is an external device, via the same interface cable 110. The ink face 28 is an interface unit that performs interface matching in data transmission to the semiconductor memory generation device 2. As a result, the final image data of the test pattern stored in the storage device such as the floppy disk 16 is transferred to the central processing unit I.
It is sent to the semiconductor memory generation device 2 under the control of 01;++.

The semiconductor memory generating device 2 is a writing device, such as a ROM writer, which writes the received image data of the test pattern into the semiconductor memory element 3. The semiconductor memory element 3 is, for example, a device in which a user can write stored data, and the memory contents do not disappear even when the power is turned off.
RI(Progran+mable Read 0nl
y Memoryl etc. are advantageously applied.

Data reading section 30, D/A converting section 32, image processing system 3
4 and a monitor system 36 are playback devices that play back the image information of the test pattern stored in the semiconductor memory module 3 as a test pattern image. The pig readout unit 30 is a readout circuit for image data stored in the memory element 3. The D/A converter 32 converts the digital image data read out by the data readout unit 30 into analog image data. The image processing system 34 is a signal processing unit that converts the image data converted into analog image data into an image signal suitable for the monitor system 36. The test pattern chart created by the personal computer 1 is reproduced by the monitor system 36 after being subjected to signal processing in this manner.

As a result, characteristics evaluation and adjustment of the image output system are performed.

FIG. 3 shows the procedure of the test pattern generation method in this embodiment. The information flow of steps 1 to 2 shown in the figure is shown corresponding to the dotted lines 1 to 2 in FIG. The process flow of the test pattern generation method in this embodiment will be explained using FIGS. 1 and 3.

Step (2) is a process for generating pattern charts from Des 1 to 1 using a personal computer. That is,
In this procedure, the floppy disk 16 storing the test pattern generation program is loaded into the disk drive (FDD controller) 14, and the test pattern generation program is loaded into the main memory 12. This starting operation causes the computer 1 to create an original chart of the test pattern.

In this embodiment, since the personal computer 1 has a digital color display function, when creating a test pattern, there is a difference between the gradation of the test pattern to be created and the display color of the CI (color display of the T display terminal 24). , a certain correspondence relationship is established in advance. Fig. 4 shows an example of a gradation conversion table showing this correspondence relationship in this embodiment. As shown in the figure, the test pattern to be created is A certain relationship is established between the gradation and the display color of the color display of the CRT display terminal 24, such as, for example, the brightness of red in color code 2 is a level 81 of riverish gray.

Note that although an example of level setting is shown here when the gradation level is 0 to 255 steps, the color code assignment and level setting values shown in the figure can of course be set arbitrarily. . In this way, by setting the brightness level of each display color using the gradation conversion table, it is possible to visually represent intermediate gradations (intermediate brightness levels), which cannot be expressed with a normal personal computer, on a color display. It becomes possible.

The personal computer l converts pixel data to be displayed on the CRT display terminal 24 into a video R for each display color.
It is stored in AM26 as digital data. For this reason,
In step 0, the pixel data constituting the test pattern screen drawn on the screen of the CRT display terminal 24 can be easily retrieved to the outside by, for example, a screen control command built into the test pattern generation program. The central processing unit 10 reads the screen information of the original chart created in accordance with this control program as digital data for each pixel in the order of scanning lines,
The data is converted into gradation information according to the gradation conversion table and saved as a file as time-series pixel data.

Step (2) is carried out by the central processing unit IO according to the control program as necessary, and gives arbitrary characteristics, such as low-pass filter characteristics, to the file-format pixel data through calculation processing.

In step ①, the central processing unit performs sub-sampling (thinning of pixel data) and one-time division multiplexing (TDM) using the installation program.
I or the addition of a synchronization signal, etc., to a data format that matches the signal format determined by the image output system to be applied.
This process converts pixel data that has been converted into a file.

Step (2) is a task in which the central processing unit 10 converts the image information, which is the final pixel data of the test pattern created through the above process, into a file according to the control program and stores it in a storage device such as the floppy disk 16.

Step (2) is a transfer process for transferring the image information stored on the floppy disk to the memory generation device 2. That is, when the final image data is recorded on the floppy disk 16 as a data file for time storage, the central processing unit 1o transfers this image data. As a result, this image data is transferred to the R3-232C interface 2.
8 to the semiconductor memory generation device 2. This transfer process is performed, for example, by loading a predetermined file transfer program into the main memo month 2.

The above is software processing, and any procedure can be realized on a general-purpose personal computer. Step (2) shows the creation of the semiconductor memory element 3 in which the image information of the test pattern is stored by the semiconductor memory generation device 2. When this semiconductor memory element 3 is created, the image information of the test pattern data stored therein is read out by the data reading section 30 and converted into an analog signal by the D/A converting section 32. Then, the image processing system 34 processes the image into a format determined by the reproduction system and displays it on the monitor system 36.

FIG. 5 shows an example of the display in this embodiment displayed on the CRT display terminal 24 and the monitor system 36, and FIG. 6 shows an example of conversion of the number of pixels from the CRT display terminal 24 to the monitor system 36 in the same display example. It is shown. This embodiment will be specifically explained using these figures. The screen display 50 shown in the upper part of FIG. 5 is an example of the screen display of the CRT terminal 24 described in step (3) of FIG. Further, a screen display 510 shown in the lower row is an example of a test pattern in a screen configuration determined by the applied system, and is an image image similar to the one-screen display 500.

The screen display 50 represents a portion of the entire test pattern shown in the one screen display 510 divided into four parts. This is a measure to increase the resolution of the test pattern. That is, on the CRT display end 24, data is processed on an enlarged screen, and for the remaining screens, all pixel data is calculated by calculation using the symmetry of the test pattern. Hereinafter, in order to facilitate understanding, explanation will be given using specific numerical values as an example, but of course the numerical values of this embodiment are not limited to these.

The CRT display terminal 24 of the general-purpose personal computer 1 is generally connected to the computer 1, and has a screen configuration of 640 x 480 pixels as described above. For this reason, although it depends on the design of the test pattern to be created, if the entire screen is represented only by the pixel density of the CRT display terminal 24, a satisfactory resolution cannot be obtained.To solve this problem, the test pattern is created. The number of pixels of the CRT display terminal 24 is converted as follows.
Although the screen configuration of No. 6 is uniquely determined by the system to which it is applied, in this example it is assumed to be 384×480, and a pattern AIEIFIGI is created for this as shown in the figure.

That is, using the personal computer 1 in the manner described above, the pattern AD(:D) shown in the screen display 500, which is a quarter screen of the pattern AIEIFIGI, is created on the display 24 through software processing by the test pattern generation program. Next, when the pixel configuration of the screen is set as shown in the screen display 500 and the screen display 510, the pattern ABCD shown in the single screen display 500 and the pattern AIEI of the monitor system 36 are
Between the coordinates (n, m) on the FIGI plane, the following formula f1. It is possible to have the following relationship.

xm (number of pixels between AB - 2) / (number of pixels between At old) l=INT1472/24
0Xm+l) f days, n=1. 2. 3.
・-,l! 112m=1.2.3. ---. 2
40 Also, the INTf expression) is a function that gives an integer value.

The relationship regarding such conversion of the number of pixels can be expressed as shown in FIG. A pixel 200 indicated by a circle in the figure indicates one pixel of the display terminal 24,
Also, Enoa220 with 9 pixels surrounded by dotted lines. For example a
= pixel i is displayed as the actual test pattern 1
It is a pixel. Based on this relationship, the representative values Dx, y of the pixel data on the upper surface of the ABC mouth can be determined as shown in the following equation.

Dx, y = (a+b+c+d+e+f+g+
h+i)/9 [2] However, a
, b, , , , i are the center coordinates (x,
y) point and its surrounding pixels, and the representative value Dxy is calculated as the coordinate (n, m) on the actual pattern AIBICLDI plane using the formula! The coordinates are transformed by 11. Since the pixel data of the actual test button has the relationship shown in equation (2), a, which constitutes this,
Depending on the values of b, c, . . . , intermediate gradation levels other than those shown in FIG. 4 can be set.

Further, although the pixel data calculation formula shown in Equation 5 (2) is a simple arithmetic average in this example, it is also possible to arbitrarily weight the data of each pixel as necessary.

In this example, by converting the pixel configuration, the average value of the fine image composed of nine pixels on the CRT display end SONG 24 can be made into the data of one pixel of the actual test pattern. . For this reason, it is possible to smooth out changes in H-number data values that are unique to the 24-screen CRT terminal, and it is also possible to increase the gradation levels that can be displayed as a test pattern, improving the overall resolution of one screen. In this example, the data was created by dividing the entire test pattern screen into four, but the division method is of course determined by the resolution, the design of the test pattern, etc., and the entire screen can be divided by software processing. can be synthesized. Further, although a general-purpose personal computer is used in this embodiment, the present invention is of course not limited to this, and can of course be applied to an office computer or workstation. Furthermore, with the improvement in the performance of computers that create test patterns, if a computer with a multicolor display function is used, the number of combinations shown in FIG. A color screen can also be created using a similar method. Therefore, the present invention can be widely applied to all fields of use that display images, such as single-image communication equipment and broadcasting equipment.

(Effects of the Invention) According to the present invention, the drawing function and information processing function of a computer can be realized without using test charts created using specialized techniques or optical devices that require skill to handle. Using these, it becomes possible to create a test pattern.

Further, in the present invention, the created test pattern is stored on the semiconductor memory element by being transferred as image information using the data transfer function of the computer. Therefore, the image of the test pattern can be reproduced at any time by an image output system that performs image quality evaluation. In addition, the present invention allows the original chart of a test pattern to be processed by software on a computer display. Therefore, the created test pattern can be visually checked and corrected almost immediately, and the data can be stored and used as test pattern data. Therefore, it is possible to replace some screens such as superimposing, and the degree of freedom when designing test patterns can be increased.

[Brief explanation of the drawing]

FIG. 1 is a block configuration diagram of hardware used in an embodiment of the test pattern generation method according to the present invention, FIG. 2 is an explanatory diagram showing a processing example of the test pattern generation method in the prior art, and FIG. FIG. 4 is an explanatory diagram showing the procedure of the test pattern generation method in this embodiment. FIG. 4 is a table configuration diagram showing an example of correspondence of the gradation conversion table in this embodiment. FIG. 5 is a screen configuration of a test pattern in this embodiment displayed on a CRT display terminal and a monitor system, and FIG. 6 is an explanatory diagram specifically showing an example of conversion of the number of pixels in this embodiment. Main 0 - Description Personal computer semiconductor memory generation device, semiconductor memory element central processing unit main memory, CRT controller CRT display terminal video RAM data readout, D/A conversion section, image processing system monitor system Patent applicant Oki Electric Industry Co., Ltd. Company Nippon Telegraph and Telephone Corporation Representative Number Takao Maruyama Takao Gradation conversion table in this embodiment Figure 4 Conversion of prime numbers Figure 6 Test in this embodiment? Turn screen configuration Figure 5

Claims (1)

[Claims] 1. In a test pattern generation method for creating a test chart for evaluating the image quality of an image output system, the method includes: a display is connected, and when displaying an image on the connected display, the screen display Create and display an image of an arbitrary pattern on the display by a program using a computer that stores the image information to be displayed in the internal memory for the display, and when the image is displayed on the display, the internal memory for the screen display By converting the image information of the image stored in the memory into data into gradation information and into a data format suitable for the image output system that performs image quality evaluation,
A test pattern generation method comprising the step of creating image information to be used as a test pattern for the image output system. 2. The test pattern generation method according to claim 1, wherein the image information is a color image signal. 3. In the storage test pattern generation method according to claim 1, the image information converted into a data format suitable for the image output system is transferred by the computer to a semiconductor memory generation device, and the semiconductor memory generation device converts the image information into a semiconductor memory generation device. A similar image of the image displayed on the display of the computer is reproduced by the image output system that performs the image quality evaluation by being stored in the memory element, read out from the semiconductor memory element, and subjected to predetermined signal conversion processing. A test pattern generation method characterized by: