JPH04195191A - Method and device for diagnosing memory for look up table - Google Patents

Abstract

PURPOSE:To allow the visual inspection and evaluation of a memory for LUT by reading a test pattern which expresses the combination of various picture element signals out of a frame memory and displaying this pattern through the memory for LUT. CONSTITUTION:The image information including the color and brightness indices forming the test pattern is stored into the frame memory 1 and the picture element signals thereof are applied to a memory 2 for the look up table (LUT) and are converted to the color and brightness information corresponding to the color and brightness indices of the picture element signals by the LUT stored into the memory 2. The converted color and brightness information is converted to video signals by a D/A converter 3. The video signals are outputted to a CRT (cathode ray tube) 4 as a display means. The memory 2 is easily inspected and diagnosed in this way by an operator's visual observation without requiring separate measuring instruments, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention provides a method for storing lookup tables used to convert at least one of color and brightness indicators of image data into at least one of color and brightness information. The present invention relates to a look-up table memory for processing, and more particularly to a look-up table memory diagnostic method and apparatus for inspecting and diagnosing the look-up table memory.

[Prior Art] Raster scan type graphic displays generally scan raster (bright lines) over the entire display screen several thousand times per second.
scan. Therefore, the time required to scan one pixel is extremely short. The lookup table has the function of converting the color and brightness index of each pixel read from the frame memory for storing display image information into color and brightness information of each pixel for display and outputting the result. It is a type of table that is stored in memory. The look-up table memory that stores this look-up table also requires a very short readout time in accordance with the time required to scan one pixel in raster scanning. This readout time becomes shorter as the number of pixels that make up the display screen increases;
When scanning 8×2048 pixels at 60 Hz, the speed is approximately 4 n5ec (nanoseconds) per pixel. For this reason, in reality, in many cases, there is a method of preparing multiple sets of memories as look amplifier table memories, writing the same contents to them, and outputting the color and brightness information of multiple pixels in parallel. Be taken.

Due to the unique structure of look-up table memory and the need for high-speed reading, it is not possible to use the same testing and diagnosis techniques as for general memory when testing and diagnosing look-up table memory. many. Therefore,
Conventional diagnosis of look-up table memory involves providing all pixels with the same or repeating pattern of color and brightness information and checking the output from a measuring instrument such as an oscilloscope. ing.

[Problems to be Solved by the Invention] The conventional inspection and diagnosis techniques described above have a problem in that a measuring instrument such as an oscilloscope must be connected to the look-up table memory for confirmation. Furthermore, since the color and brightness information given to the pixels is uniform or the same pattern is repeated, there is a problem that the combinations of memory read timings that can be tested are limited.

The present invention has been made in view of such problems, and includes:
It is an object of the present invention to provide a method and apparatus for diagnosing a memory for a look-up table, which is simple without using a measuring instrument or the like, and which is not limited by combinations of memory read timings.

[Means for Solving the Problems] A look-up table memory diagnostic method according to the present invention includes a frame memory in which index data of at least one of color and brightness for each pixel is stored, and a predetermined raster image stored in the frame memory. a look-up table memory storing a look-up table for converting the index data read out according to a scanning method into a signal of a corresponding color and a low brightness; and a signal of at least one of the color and brightness. Diagnosis of the look-up table memory in a raster scan type graphic display, comprising signal converting means for converting a video signal into a video signal according to the predetermined raster scan method, and display means for receiving the video signal and displaying an image. In the method, index data of at least one of color and brightness is stored in advance in the frame memory according to a test pattern having a predetermined image pattern, and the index data stored in the frame memory is stored in the look-up table memory. The present invention is characterized in that the test pattern is displayed on the display means as a test pattern reflecting the correctness of at least one of the color and brightness signals of the look-up table.

A memory diagnostic device for a look-up table according to the present invention has a pattern having a width of 1 pixel and a width of N pixels (N is a natural number) having at least one of an arbitrary color and a brightness index that is not 0, with one pixel in between. Alternately and sequentially changing N, they are arranged corresponding to the first direction on the screen, and the second direction on the screen is
, the array in the first direction is divided pixel by pixel in the first direction.
A frame memory in which test patterns sequentially arranged while being shifted in the direction of a lookup table memory in which a lookup table to be inspected is stored, and a signal conversion means for converting at least one of the color and brightness information output from the lookup table memory into a video signal. and display means for receiving the video signal and displaying an image of the test pattern.

[Function] In the look-up table memory diagnostic method and device of the present invention, index data of at least one of color and brightness is stored in advance in a frame memory according to a test pattern having a predetermined image pattern. Since the index data stored in the frame memory is displayed on the display device via the lookup table memory as a test pattern reflecting the correctness of at least one of the color and brightness signals of the lookup table, separate measurements are not required. The look-up table memory can be easily inspected and diagnosed by the operator's visual inspection, which requires equipment or the like. In particular, the test pattern is a pattern having a width of 1 pixel and a width of N pixels (N is a natural number, i.e., N=1.2, 3, etc.) having at least one of an arbitrary color and brightness index that is not 0. are arranged alternately with one pixel in between, and N is successively changed by 1 to correspond to the first direction on the screen, and the arrangement in the first direction is arranged in the second direction on the screen. 1
By forming a test pattern in which each pixel is sequentially arranged in the first direction, visual confirmation by the operator described above becomes easy.

[Example] Hereinafter, an example of the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows the configuration of a raster scan type graphic display device in which a look-up table memory diagnostic technique according to an embodiment of the present invention is employed. FIG. 2 is an explanatory diagram of a pixel arrangement in the same embodiment, FIG. 3 is an explanatory diagram of a look-up table memory in the same embodiment, and FIG. 4 is an explanatory diagram of a test pattern in the same embodiment.

In FIG. 1, image information including color and brightness indicators forming a test pattern (details will be described later) is stored in a frame memory 1, and the pixel signals are stored in a look-up table (hereinafter referred to as "LUTJ"). Memory 2 for
The LUT stored in the meme memory 2 for this LUT is given to
The color and brightness index of the pixel signal is converted into color and brightness information corresponding to the color and brightness index of the pixel signal.
It is output to the A (digital-analog) converter 3. The color and brightness information is converted into a video signal by a D/A converter 3 and output to a CRT (cathode ray tube) 4 as a display means.

FIG. 2 shows the arrangement of pixels in the frame memory 1, and the pixel signals in the frame memory 1 are 1-1.1-2.
．． 1-3. ..., 1-n, 2-1°2-2. ...+
Frame memory 1 to L in the order of m L ...+mn
Two meme memories for UT are loaded.

Figure 3 shows an example of the structure of two meme memories for LUT.
In this example, LUT mememory 2-moly block 5.6.
It is composed of four memory blocks No. 7 and No. 8.

Pixel signals for 4 pixels simultaneously from frame memory 1 (3rd
Pixel signals 9.10.11 and 12 are shown in the figure) are read out and input into memory blocks 5.6.7 and 8 of the LUT memory 2, respectively.

Pixels 1-1.1-5.1-9 shown in FIG. ...i
−(4j+1) (i = 1~m, j = 0−
(n-1)/4) is the pixel signal 9 in the memory block 5.
, pixels 1-2.1-6. ...i-(4j+2) is stored in the memory block 6 as the pixel signal 10, and pixels 1-3 .
1-7. . . . i-(4j+3) is sent to the memory block 7 as the pixel signal 11, and the pixel 1-4.1-8.・・・
-i-(4j+4) are inputted to the memory block 8 in sequence as the pixel signals 12, respectively. At the timing according to the input of each pixel signal 9 to 2, the color and brightness information signal 13
~IEi C/A:I Output to inverter 3. In this case, since 4 pixels are input and output at the same time,
Each memory block 5.6.7 and 8 of memory 2 for LUT
This means that the readout time may take up to four times the scanning time for one pixel.

FIG. 4 shows a test pattern stored in the frame memory 1, in which the white and black parts take on different colors or brightnesses. The color or brightness indicated by black is given to the pixel 1-1, white is given to the pixel 1-2, black is given to the pixel 1-3, and white is given to the pixel 1-4 to the pixel signal. Similarly, pixel 1-5 is black, pixel 1-6 is white, pixel 1-7 and 1-8 is black, ... pixel 2-1 is white, pixel 2-2 is black, ...Subsequently, the same color or brightness is given to each pixel signal.

That is, a pattern of width 1 pixel and width N (N=1.2.3...: natural number) pixels is alternately spaced by 1 pixel each, and N is increased by 1, starting from the left. A pattern is arranged to the right, and in the vertical direction, similarly formed rows are sequentially moved one pixel to the left.

In this way, the LUT memory 2 is configured to store a test pattern in the format shown in FIG. 4 in the frame memory 1, read it out, convert it in the LUT memory 2, and display it on the CRT 4. Various combinations of pixel signals input to each memory block 5 to 8 can be evaluated, and furthermore, in this case, the pattern actually displayed on the CRT 4 consists of a straight line with an inclination of 45° from the upper right to the lower left. Therefore, the state of the output signal from the LUT memory 2 can be easily checked visually.

The present invention is not limited to the above-described embodiments, and for example, a display device other than CRT4, such as a liquid crystal display device, may be used as the display means, and a test pattern other than the test pattern shown in FIG. 4 may be used as the test pattern. In addition, various modifications may be made without departing from the gist of the present invention, such as by using LUT to convert both or one of color and brightness information.

[Effects of the Invention] As described above, according to the present invention, test patterns that can express various combinations of pixel signals and that can easily confirm abnormalities by visual inspection are stored in a frame memory,
Since this test pattern is read out and displayed via the LUT memory, the LUT
To provide a look-up table memory diagnostic method and device, which can inspect and evaluate a look-up table memory, and can easily visually confirm the state of an output signal from an LUT memory based on a displayed pattern. I can do it.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a raster scan type graphic display device in which a look-up table memory diagnostic technology according to an embodiment of the present invention is adopted, and FIG. 2 is a pixel arrangement in the frame memory shown in FIG. An explanatory diagram of, Figure 3 is the lookup table (LUT) of Figure 1.
FIG. 4 is a diagram schematically showing the configuration of memory blocks in the frame memory of FIG. 1. FIG. 1; Frame memory, 2; Lookup table (LU
T) memory, 3; D/A funverter, 4; CRT, 5
~8; Memory block

Claims (2)

[Claims] (1) A frame memory that stores index data of at least one of color and brightness for each pixel, and a frame memory that stores index data of at least one of color and brightness for each pixel, and a frame memory that stores index data of at least one of color and brightness corresponding to the index data read out from the frame memory according to a predetermined raster scan method. a look-up table memory storing a look-up table for converting into a signal; and a signal conversion means for converting at least one of the color and brightness signals into a video signal according to the predetermined raster scan method;
In the method for diagnosing the look-up table memory in a raster scan type graphic display comprising display means for receiving the video signal and displaying an image, the frame memory has a predetermined image pattern in advance, and a color according to a test pattern is provided. The index data of at least one of color and brightness is stored in the frame memory, and the index data stored in the frame memory is passed through the look-up table memory to determine whether the signal of at least one of color and brightness in the look-up table is correct or incorrect. A method for diagnosing a memory for a lookup table, characterized in that a reflected test pattern is displayed on the display means. (2) A screen with a pattern of 1 pixel width and N pixels (N is a natural number) having at least one of an arbitrary color and brightness index that is not 0, and changing N alternately and sequentially with 1 pixel in between. The test patterns are arranged in correspondence with the first direction above, and test patterns are stored in advance in a second direction on the screen, in which the arrangement in the first direction is shifted by one pixel in the first direction. A look-up table to be inspected is stored, which receives at least one of color and brightness index information output from the frame memory and outputs a corresponding color and brightness information signal. a look-up table memory; a signal conversion means for converting at least one of the color and brightness information outputted from the look-up table memory into a video signal; 1. A lookup table memory diagnostic device, comprising display means for displaying a lookup table.