JPS6130311B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a display device that displays grayscale images.

Conventionally, in this type of display, the maximum and minimum density values of the image are used to linearly expand and transform the density values to display the image in a highlighted manner. Moreover, the display gradation level (quantization level) is fixed at the maximum value minus the minimum value + 1, and there is a drawback that the display gradation level cannot be changed online when recognizing a pattern in an image.

Furthermore, when attempting to change the number of display gray levels for a plurality of regions, there is a drawback that as many gray value converters as there are regions are required.

An object of the present invention is to eliminate these drawbacks in conventional display devices, expand the density value within the image display device, and at the same time change the display gradation level to an arbitrary level different from that of the original image, and furthermore, the absolute value of the density value of the original image itself. The objective is to provide a display device that is not modified in any way.

Another object of the present invention is to allow an operator to select a target area in real time while looking at a display screen, highlight only a pattern in an arbitrary area in an image, and perform quantization display at equal intervals. The goal is to provide equipment.

Another object of the present invention is to perform quantization display without increasing the number of density value converters by using only one density value converter and controlling the reading address of the gradation or color code for each emphasis area. The objective is to provide a device that performs the following.

According to the present invention, the image information stored in the image memory is sequentially read out from the image memory, and in order to allocate the gradation or color corresponding to the density value, the gradation value converter is configured with a random access memory. Or, in an image display device that displays a color image, an arbitrary-shaped one in the image memory
an area designator for specifying one or more boundaries, and a quantization controller for controlling a read address of the shading or color code from the density value converter in order to change the number of display shading levels of the area, It is possible to obtain an image quantization device that emphasizes each emphasis area at a different display density level during display.

Next, details of the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of a quantization device according to the present invention. In FIG. A density value, usually consisting of several bits, for each pixel is stored as image data in a flash memory. Reference numeral 3 denotes an area designator that determines the boundary of the emphasized area on the screen and indicates the number of display gray levels for each area; 4 denotes a density value converter that outputs a gray scale or color code corresponding to the density value of each pixel; and 5, A quantization controller that controls the readout address of the gray scale or color code in the density value converter 4 for each area according to the number of display gray levels in each area; 6 is a digital output of the density value converter 4; This is a digital/analog converter that converts a signal (color code) into an analog three primary color signal (red, green, and blue) and supplies the signal to the display device 1.

Now, assuming that the image data is 6 bits, the density value converter 4 has 64 types of three primary color components (color codes) indicated by address numbers from 1st to 64th, and each color component is made up of a 6-bit code. Suppose there is. When reading a color code using the random access memory, the density value converter 4 can read out the color code corresponding to the image data by applying the image data as an address signal to the read signal line. Assume that 64 types of color codes are stored in the density value converter 4 in advance.

A method of highlighting a partial area within an image using its maximum density value (MAX) and minimum density value (MIN) has already been disclosed, for example, in Japanese Patent Application No. 126305/1982 (Japanese Patent Application Laid-open No. 59030/1983). Since it is described in detail in "Color Image Highlighting Display Device", an outline will be explained here.

The region designator 3 is given the starting point coordinates and width of a rectangular designated emphasis region, and while reading the image from the refresh memory 2 in raster format, it compares the coordinates of the read pixels and the region range coordinates. to determine whether the area is inside or outside the area.

of the concentration value converter 4 corresponding to the maximum value of the original data.
The maxth value is made to appear as the 64th color code, the minth value corresponding to the minimum value is made to appear to be the 1st color code, and the space between them is divided linearly or nonlinearly. For example, in the case of linearity, when the density value of a certain pixel is X _O (minX _O max), it is converted as shown in the following equation, and the density value converter 4 reads out the converted density value X _N when it is displayed. It is used as an address to highlight the density value in the refresh memory 2 without changing it.

X _N =X _O -min/max-min x 63 (1) Next, the quantization method in the present invention will be explained.

For the sake of simplicity, the explanation will be made assuming one emphasis area.

FIG. 2 is a diagram illustrating a method for controlling the reading of color codes from the density value converter 4 according to the number of display gray levels, and the same parts as in FIG. 1 are given the same numbers. As an example, if the density value in the region is
Consider the case where MIN to MAX is displayed in 4 levels. Possible range of concentration value (1 to 64)
Divide the area from MIN to MAX into four equal parts, and divide the area from the bottom into sections A, B, C, D, and sections smaller than MIN as E,
Assuming that the interval larger than MAX is F, it is determined which of the six intervals the density value of the pixel in the emphasis area read from the refresh memory 2 belongs to, and if it is in the interval A or E, the density 1st value converter 4, 64th if section D or F, section B or C
If so, the address that divides the density value range into three equal parts, i.e.
It is sufficient if the 22nd and 43rd color codes are read respectively.

This can be formulated as follows. Display gray level is L, pixel density value is G, density value converter 4
Let A be the read address of MIN<G<
At MAX, A=(64×IN)/(L-1)...(1) However, IN=(G-MIN)/IP IP=(MAX-MIN+1)/L Division to find A, IN, and IP is an integer calculation.
Also, when GMIN, A=1, and GMAX,
A=64. However, the quantization level L is MAX-
Assume that it does not exceed MIN+1.

The details of one embodiment of the quantization controller 5 that specifically implements the method described above will be explained using FIG. 3.

The area designator 3 determines whether the pixels sequentially read out from the refresh memory 2 are inside or outside the designated emphasis area, and outputs "1" to the signal line 501 if the pixels are within the area. On the other hand, the density values G of the pixels read out at the same time are given to the quantization controller 5 via the signal line 201. For normal display, the AND circuit 59 is not open, and the input pixel G supplied via the signal line 201 is open, and the AND circuit 58 is open, and the OR circuit 7
3 as the read address value of the density value converter 44.

The following describes the display of pixels in areas that are not normally displayed. It is assumed that the minimum quantization value MIN, the maximum value MAX, and the number of levels L are already stored in the registers 51 to 53 via terminals 11 to 13, respectively. Each value of the registers 51 to 53 is read out by the within-area determination signal of the within-area signal line 501. The values of MIN and MAX are given to a subtracter 54 to find MAX-MIN, and then sent to an adder 55.
1 is added to this, and the result of MAX-MIN+1 is given to the divider 57.

On the other hand, the quantization level L is given to the divider 57,
IP is output to the signal line 502. AND circuit 5
The density value G of the pixel given through the comparator 6
0 and is applied to a comparator 63 via an AND circuit 62 and compared with MIN and MAX, respectively. When the input pixel value is smaller than MIN, the signal line 50
“1” is output to register 61.
A value “1” stored in advance is output to the signal line 504. Since AND circuit 62 is not opened at this time, G is not applied to comparator 63 and AND circuit 66. The value “1” on the signal line 504 is applied to the read address signal line of the density value converter 4 via the OR circuit 73. As a result, the first color code of the density value converter 4 is read out. G is
If it is larger than MIN, the output of the signal line 503 becomes "0" and the value of the register 61 is not output.

On the other hand, at this time, the AND circuit 62 opens and G and MAX
is input to the comparator 63, and when G is greater than MAX, "1" is output to the signal line 505. As a result, the value "64" previously stored in the register 64 is output to the signal line 506 as A=64,
The 64th address of the density value converter 4 is designated via the OR circuit 73.

If G is greater than MIN and less than MAX,
G is applied to a subtracter 67 via an AND circuit 66 to obtain G-MIN, and a divider 68 further obtains (G-MIN)/IP. This value is further multiplied by the maximum address (64 in this case) of the concentration value converter 4 given from the terminal 14 in a multiplier 69, and further multiplied by (L-1) given from the subtractor 56 in a divider 70. Division is performed and A in equation (1) is obtained. A' is compared with the maximum address of the density value converter 4 in the comparator 71, and if it is larger than that, A' is suppressed to 64, A is not output to the signal line 507, and the value "64" of the register 64 is output. be done. When A is 64 or less, it is output to the signal line 507 via the AND circuit 72, and the A-th color code of the density value converter 4 is read out via the OR circuit 73.

In this embodiment, in order to simplify the explanation, the emphasis specification area is explained as one, but the invention is not limited to this, and in the case of two or more areas, MIN,
The system can be easily expanded by storing initial values equal to the number of regions in each of the MAX and L registers, and reading out the values corresponding to the regions of the read pixels.

For example, A. Rosenfeld's “Digital Picture
Processing”, pp.333−403, Academic Press
(1975), etc., and can be easily applied.

In this case, the area designator 3 determines in which area the pixel to be read out in raster format is included, and registers 51 to 55 are registered in advance for that area.
All you have to do is read out the MIN, MAX, and L values stored in the .

As explained above, with the quantization device of the present invention, a plurality of display gray levels can be specified independently, and moreover, it is possible to control the readout address without changing the content or number of conventional density value converters. ,
Emphasis can be displayed, and the display effect can be increased.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of an image quantization device according to an embodiment of the present invention, and FIG. 2 is a diagram explaining the principle of controlling the color code read address from the density value converter for quantized display. , FIG. 3 is a diagram explaining the operation of the quantization control panel. In the figure, 1 is a display device, 2 is a refresh memory, 3 is an area designator, 4 is a density value converter, and 5 is a refresh memory.
is a quantization controller, and 6 is a digital/analog converter. 51 to 53 are registers, 54 is a subtracter, 55 is an adder, 56 is a subtracter, 57 is a divider, 60 is a comparator, 61 is a register, 63 is a comparator, 64 is a register, 67 is a subtracter, 68 is a divider, 69 is a multiplier, 70 is a divider, and 71 is a comparator.

Claims (1)

[Claims] 1. Image information stored in an image memory is sequentially read out from the image memory, and a density value converter configured with a random access memory is configured to assign a density value or color corresponding to the density value to a density value or color image. In an image display device that displays a and a quantization controller that controls the reading address of the gradation or color code from the density value converter in accordance with the density value of each pixel according to the designation of the number of display levels and the quantization range. An image quantization device that emphasizes each emphasis area at a different display gradation or color level during display.