JP2619952B2 - Gradation conversion method - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gradation conversion method and a memory element suitable for a flat display such as a liquid crystal display device and a plasma display device used in a personal computer or the like.

[Prior Art] In a personal computer (hereinafter abbreviated as a personal computer) or a workstation, a color display using a color CRT is generally used. Many application softwares are developed for color display.

On the other hand, in response to the need for miniaturization of equipment, a large number of personal computers called laptop type (kneeling type) have been commercialized. In the laptop type, to reduce the weight and to make the device thinner, the display device uses a normal CRT
Instead, a liquid crystal or a plasma panel is used. Less than,
These are collectively called a panel display. By the way, the panel display is still expensive, although a color type liquid crystal panel has been developed in part, and is usually a single color display. Therefore, when a color application for a color CRT is operated on a laptop personal computer having a panel display, there is an inconvenience that a color difference is completely invisible.

For this reason, in a panel display, gradation display is often performed by changing the lighting time of a display dot, and a color difference is often expressed as a gradation difference. At this time, how to convert the color information into the gradation information is important in viewability of display.

FIG. 4 is a block diagram showing a general configuration for performing gradation conversion in an information processing apparatus, for example.

In the figure, 1 is a CPU, 2 is a CPU bus, 3 is a display controller, 5 is a display memory for storing display contents, 7 is a pallet circuit for converting logical color data 9 into physical color data 10, and 8 is a physical circuit. A gradation conversion circuit for converting the color data 10 into gradation data 11, and 12 is a panel display.

FIG. 5 shows a configuration example of the pallet circuit 7.

In FIG. 1, a pallet circuit 7 is a kind of RAM that receives logical color data 9 as output data of a display memory 5 as an address input and physical color data 10 as a data output. In the example of FIG. 5, the display memory 5 has a four-plane configuration of planes 0 to 3, and the logical color data 9 can distinguish up to 16 colors. The internal RAM of the pallet circuit 7 is, as in this example,
If RGB (Red, Green, Blue), which are the three primary colors of light, have 6-bit luminance information as data, ²⁶ × ²⁶ × ²⁶ = 262,144 colors are output as physical color data 10 it can. At this time,
The logical color data equivalent to the address input of the pallet circuit 7 is 4 bits and can represent 16 colors. Therefore, the pallet circuit 7 in this figure is a circuit for converting 16 colors to 262,144 colors or 16 of 262,144 colors. In other words, a circuit that displays By using the pallet circuit 7, the display color can be changed without rewriting the contents of the display memory 5, so that the speed can be increased.

The palette function is also called a color look-up table, and is described in detail in Japanese Patent Publication No. 54-37943.

By the way, in CRT, since subtle color expression is possible,
Such information having a large number of colors can be displayed as it is. However, the panel display has a limit of about 4 to 16 gradations, and it is technically difficult to increase the gradation further, and there is a restriction that it is difficult for a user to distinguish the gradation.

FIG. 6 shows an example of the gradation conversion circuit 8 for converting the information of 262,144 colors obtained above into eight gradations.

In this example, each of the 6 bits of RGB is divided into two bits by an OR circuit 8.
By ORing with 1 to 83, 3-bit gradation data 11 is created.

An example of a technique relating to color assignment when such color display data is displayed on a monochrome display is described in Japanese Patent Application Laid-Open No. 59-105684. Also,
One of the methods of performing gradation display on a panel display is as follows.
It is described in JP-B-58-57192.

Incidentally, there is a dual-port memory as a memory element suitable for use in the display memory 5. FIG. 7 shows a block diagram of the dual port memory.

In the figure, 25 is an address buffer, 26 is a parallel data input / output buffer, 27 is a row decoder, 28 is a column decoder, 29 is a memory cell, 30 is a data register, 31 is a data selector, 32 is a serial data input / output buffer, 33 is an address pointer.

Data access from the parallel port 35 is a general DR
Same as AM (Dynamic Ram). That is, the row address first input from the address port 34 is input to the row decoder 27 after passing through the address buffer 25, and is used to select one row of the memory cells 29 and read the data. The second column address input from the address port 34 passes through the address buffer 25, and then the column decoder
It is used to select 1-bit parallel data representing one pixel from one row of data input to the memory cell 28 and read from the memory cell 29. The 1-bit parallel data is output from the parallel port 35 after passing through the parallel data input / output buffer 26.

On the other hand, data access from the serial port 36 is performed as described below. First, a row address is input from the addressed port 34, and one row of the memory cells 29 is selected. At this time, by activating the transfer control signal 37, one row of data read from the memory cell 29 is transferred to the data register 30 and stored. The address pointer 33 counts up the address pointer value 39 every time one pulse of the clock signal 38 is input. The data selector 31 sequentially selects one bit at a time from the data in the data register 30 in accordance with the address pointer value 39, and outputs the data to the serial data port 36 through the serial data buffer 32.

In the above-described dual port memory, for example, if data of one line of the display screen is stored in one row of the memory cell 29, row data is transferred to the data register 30 once before displaying each line, and thereafter, Can output display data in sequence only by inputting the clock signal 38. For such dual port memory,
This is discussed in detail in JP-A-59-131979.

[Problems to be Solved by the Invention] In other words, the above-described gradation conversion compresses, for example, color data of 260,000 colors into only 8 to 16 gradations. May have the same gradation even if the color is the same, and the user may not be able to recognize the difference in color on the screen. This will be described using the gradation conversion circuit 8 in FIG.

For example, among the physical color data 10, in R2 ⁰ ~R2 ⁵ are all "1", when the G2 ⁰ ~G2 ⁵ and B2 ⁰ ~ B2 ⁵ are all "0" and,
B2 ⁰ ~ B2 in ⁵ the case of all "1" in the G2 ⁰ ～G2 ⁵ and R2 ⁰ ～R2 ⁵ are all "0", both 2 ^{0-2 2} becomes "1" of the gray scale data 11, The display luminance on the panel display 12 becomes the same. However, the former is a case in which R is to be displayed, that is, red, while the latter is a case in which B, that is, blue is to be displayed, so the colors are actually completely different. As described above, the problem of converting different colors into the same gradation always occurs depending on the combination of colors even if another conversion circuit is used.

If the pallet circuit 7 is removed and the logical color data 9 is directly connected to the gradation data 11, even if the software attempts to change the display color and writes to the pallet circuit 7, it is ignored. Thus, the display screen does not change. Therefore, there arises a problem that the compatibility of software appearance is impaired. Therefore, the pallet circuit 7 is necessary in the configuration, and the gradation data 11 must be created from the physical color data 10.

The dual port memory is excellent in that display data on a display screen can be easily obtained, but cannot obtain display data of another line simultaneously with a line to be displayed. For this reason, in order to compare and process the display data of the line to be displayed and the display data of another line, there is a problem that a means for storing the data of one line must be provided separately.

SUMMARY OF THE INVENTION An object of the present invention is to solve such a problem and to provide a gradation conversion method capable of visually recognizing a color boundary even when different colors are converted into the same gradation.

Another object of the present invention is to provide an information processing apparatus that realizes such gradation conversion.

Still another object of the present invention is to provide a memory device capable of obtaining display data of another line simultaneously with a line to be displayed.

Means for Solving the Problems In order to achieve the above object, the present invention is a gradation conversion method for converting color display data into gradation display data, wherein different colors are the same or close in adjacent display areas. A means for detecting that the color is associated with the gradation of the luminance; and a means for setting a boundary line of the color to gradation data having a luminance different from the gradation by one or more steps according to the detection result. And

More specifically, the present invention relates to a gradation conversion method for converting color display data into gradation display data, wherein the means for performing gradation conversion of the color display data for a target area, Means for converting color display data into gradation data for an area adjacent to the area, and comparing the two color display data for the target area and the area adjacent thereto, and comparing both gradations,
Means for detecting a state in which the two display colors are different, but the gradation is converted to the same or similar luminance, and when the state is detected, the boundary between the two areas is defined as the two areas. Means for changing to gradation data of identifiable luminance.

Furthermore, the present invention is a gradation conversion method for converting color display data into gradation display data, wherein the display data is included in a display line different from a display line including the point together with logical color data of a point to be displayed. A display memory for simultaneously outputting logical color data of a point adjacent to the point, a pallet circuit for converting two points of logical color data output from the display memory into physical color data, and a point for performing the display. Means for converting physical color data into gradation data, means for converting physical color data into gradation data for an adjacent point on the same display line as the point at which the display is performed, and Means for converting physical color data into gradation data for a point adjacent to the point to be displayed; and for a point adjacent to the point to be displayed on a line adjacent to the point to be displayed. And comparing the physical color data with respect to the point adjacent to the point on which the display is performed on the same line, and comparing the gradations of the physical color data. At least one of the display point and the two adjacent points is Means for detecting a state in which the gradation is converted to the same or similar luminance despite different display colors; and when the state is detected, a boundary line of a display area including each point is defined by the boundary. It is characterized by comprising means for changing the area between the lines to gray-scale data of luminance that can be identified.

The present invention is a gradation conversion method that not only converts color display data into gradation data but also reduces display data of n gradations into display data of m gradations (n> m). Means for detecting that different gray scales are associated with the same or similar gray scales in the region, and setting a gray scale boundary line in the display data of n gray scales to a gray scale different from the gray scale of the association. The present invention provides a gradation conversion method characterized by comprising means for performing a gradation conversion.

In addition, the present invention converts display data of n colors into m colors (n> m).
Means for detecting that different colors are associated with the same or similar colors in adjacent display areas, and a color boundary line in n-color display data. There is provided a color conversion method characterized by comprising means for making a color different from the color of association.

Further, the present invention provides a memory element having two serial access ports in addition to a parallel access port as a display memory suitably used for implementing the above-described gradation conversion method.

Further, the present invention also provides an information processing apparatus using the gradation conversion method or the color conversion method, particularly a laptop computer.

[Operation] The means for detecting that different colors have been converted into the same gradation in the adjacent display areas includes the display color and gradation data of a point to be displayed on the display, and the one above or one above the point. The display color and the gradation data at the next lower point and the one left or one right point are compared, and it is determined whether or not different colors have been converted into the same gradation. As a result of the determination, if it is found that different colors have been converted to the same gradation, the gradation of the display point is converted to a gradation different from the gradation and displayed on the display panel. . As a result of the display, even when different colors are converted into the same gradation in the adjacent display areas, it is possible to easily visually recognize the boundary of the color on the display panel.

The data register, data selector, serial data input / output buffer, and serial data port added to the conventional dual port memory store data of a display line different from the display line and sequentially output one bit at a time. Thereby, simultaneously with the data of the display line, the data of the display line different from the display line can be easily obtained.

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

FIG. 1 is a block diagram showing a configuration of an embodiment of a gradation conversion method according to the present invention.

This embodiment is inserted and connected between the pallet circuit 7 and the panel display 12 in FIG. The information processing apparatus, for example, replaces the gradation conversion circuit 8 shown in FIG.
It is configured by incorporating the gradation conversion method of the present embodiment.

Preferred examples of the information processing method to which the present embodiment is applied include a laptop personal computer and a word processor. That is, the present invention is suitable for a computer having a display device that performs display using a plurality of gradations.

In FIG. 1, reference numeral 14 denotes a one-dot storage circuit which stores and outputs physical color data of a point one dot left of a point to be displayed on a display screen. The one-dot storage circuit 14 can be easily realized by a D latch or the like.

Reference numeral 15 denotes a one-line storage circuit which stores and outputs physical color data of a point on one line of a point to be displayed on a display screen. The one-line storage circuit 15 can be easily realized by using a line memory element. A line memory element is a FIFO (Fast In Fast Out) with a serial input terminal and a serial output terminal
Memory. For example, there is HM63210 manufactured by Hitachi, Ltd.

16a, 16b, 16c, 16d are comparison circuits, and two inputs A, B
And outputs a logical value “1” if they match.

 18a, 18b and 18c are AND circuits, and 19 is an OR circuit.

Reference numeral 17 denotes a gradation changing circuit which changes and outputs the gradation data 11 output from the gradation conversion circuit 8a.

Reference numeral 20 denotes a line count circuit which outputs a logical value "0" during a period in which the topmost line and the leftmost dot on the display screen are displayed.

Reference numeral 12 denotes a panel display capable of displaying eight gradations of a single color.

8a, 8b and 8c are gradation conversion circuits. The gradation conversion circuit 8a performs gradation conversion of the physical color data 10a of the palette circuit 7. The gradation conversion is performed on the physical color data 10b from the one-dot storage circuit 14. Further, the gradation conversion circuit 8c performs gradation conversion of the physical color data from the one-line storage circuit 15.

The one-dot storage circuit 14 and the comparison circuit 16b detect a difference in color display data between a point to be displayed in a target area and a point one dot to the left of the same display line, and a gradation conversion circuit 8b and a comparison circuit 16c. The point to be displayed and the point one dot to the left thereof, including the AND circuit 18a which detects the presence or absence of a gradation difference between these points and the AND of these detection results, A means for detecting whether or not the display data is different but the gradation is converted to the same (including the case of approximation; the same applies hereinafter) is configured.

Similarly, the one-line storage circuit 15 and the comparator 16, the gradation conversion circuit 8c and the comparison circuit 16d, and the AND circuit 18b have different color display data between the point where display is performed and the point on one line. It constitutes means for detecting whether or not the state in which the gradation is converted to the same level.

Then, an OR circuit 19 that takes the logical sum of these detection means
And means for detecting that different colors are associated with the same or similar luminance gradation in adjacent display areas.

The line count circuit 20, the AND circuit 18c, and the gradation changing circuit 17 constitute means for setting a color boundary line to gradation data having a luminance that is at least one step different from the gradation in accordance with the detection result. I have.

 Next, the operation of the present embodiment will be described.

The physical color data 10a output from the palette circuit 7 is
The data is converted into gradation data 11a by the gradation conversion circuit 8a. The physical color data 10a is stored in the one-dot storage circuits 14 and
It is stored in the line storage circuit 15.

The one-dot left physical color data 10b output from the one-dot storage circuit 14 is converted into gradation data 11b by the gradation conversion circuit 8b and compared with the physical color data 10a by the comparison circuit 16a. On the other hand, the gradation data 11b at the point one dot left is compared with the gradation data 11a at the point to be displayed by the comparison circuit 16c. The outputs of the comparison circuits 16a and 16c are
Entered in a. When the logical value of the output of the comparing circuit 16a is "0" and the logical value of the output of the comparing circuit 16c is "1", that is, the physical color data is different from the dot one dot left, and the gradation data is the same. At this time, a logical value “1” is output.

Similarly, for the physical color data 10c of a point on one dot output from the one-line storage circuit 15, the comparison circuit 16
b, 16d, and a point to be displayed by the gradation conversion circuit 8c, and when the physical color data is different and the gradation data is the same, a logical value "1" is output from the AND circuit 18b.

Further, the OR of the outputs of the two AND circuits 18a and 18b is calculated by the OR circuit 19, so that a point to be displayed and one of the points are displayed.
When the physical color data of the dot on the left or on one dot is different and the gradation data is the same, a gradation change request signal 21 having a logical value "1" is obtained.

By the way, when displaying the topmost line or the leftmost point on the display screen, there is no point one dot to the left or above the point to be displayed, so the tone change request signal obtained as described above is obtained. 21 is invalid. Therefore, the logical product of the mask signal 22 from the line count circuit 20 and the gradation change request signal 21 from the line count circuit 20, which becomes the logical value "0" during the period in which the uppermost line and the leftmost dot on the display screen are displayed, is ANDed. The gradation change signal 23 is generated by the circuit 18c.
The reason that the gradation change signal 23 has the logical value “1” is that the gradation change request signal 21 has the logical value “1” during a period other than the period in which the uppermost line or the leftmost dot on the display screen is displayed. ".

When the gradation change signal 23 has the logical value "1", the gradation change circuit 17 changes the 3-bit gradation data 11a as shown in Table 1 below, and outputs the corrected gradation data 24. Gradation change signal 23
Is a logical value "0", the gradation data 11a is output as it is as the corrected gradation data 24 without being changed.

By using the above-described corrected gradation data 24, when different colors are associated with the same gradation in the adjacent display areas, the color boundary line is set to a gradation that is different from the gradation by one step luminance. It can be displayed on a display panel.

 Next, another embodiment of the present invention will be described.

 FIG. 2 is a block diagram showing the configuration of this embodiment.

The gradation conversion device of this embodiment shown in FIG. 2 is applied to, for example, the display memory 5, the pallet circuit 7, and the gradation conversion circuit 8 in FIG. The part corresponding to the gradation conversion circuit 8 has basically the same configuration as that of the first embodiment. Therefore, the description here will focus on the differences.

 FIG. 2 is a block diagram showing the configuration of this embodiment.

The feature of the present embodiment is that the use of the display memory 5a capable of simultaneously outputting two lines of display data eliminates the need for the one-line storage circuit 15 in the first embodiment.

7a and 7b are the same palette circuit, and the same value is set.

 Next, the operation of the present embodiment will be described.

The display memory 5a simultaneously outputs the logical color data 9b of a point one dot above the point together with the logical color data 9a of the point to be displayed. The logical color data 9b is converted into physical color data 10c by the palette circuit 7b.

The physical color data 10c thus obtained is exactly the same as the physical color data 10c output from the one-line storage circuit 15 in the first embodiment. Therefore, similarly to the first embodiment, when different colors are associated with the same gradation in the adjacent display areas, the color boundary line is set to a gradation having a one-step luminance different from the gradation. It can be displayed on a display panel.

FIG. 3 is a block diagram showing an example of a video memory element for realizing a display memory 5a for simultaneously outputting two lines of display data.

25 is an address buffer, 26 is a parallel data input / output buffer, 27 is a row decoder, 28 is a column decoder, 29 is a memory cell, 30a and 30b are data registers, 31a and 31b are data selectors, and 32a and 32b are serial data input and output. The buffer 33 is an address pointer.

The feature of the present embodiment is that a serial port is added to a conventional dual port memory to form a triple port memory.

Hereinafter, the operation of reading data from the serial ports 36a and 36b will be described.

First, a row address in which data of a line to be displayed is stored is input from the address port 34. At this time, the transfer control signal 37a is activated and the transfer control signal 3
7b transfers the data of the display line read from the memory cell 29 to the data register 30a by keeping it inactive. Next, a row address in which data of a line different from the line to be displayed is stored is input from the address port 34. At this time, by setting the transfer control signal 37b to be active and the transfer control signal 37a to be inactive, data on a line different from the display line read from the memory cell 29 is transferred to the data register 30b. After the transfer, by inputting the clock signal 38, the data selectors 31a, 31b
Selects one bit at a time from the data in the data registers 30a, 30b,
Output to 32b respectively. The data input to the serial data input / output buffers 32a and 32b are transmitted to the serial ports 36a and 3b.
6b.

In this way, display data of another line can be obtained simultaneously with the line to be displayed.

Although two serial ports are provided in the present embodiment, the outputs of the data selectors 31a and 31b may be time-divided and input to the serial data input / output buffer 32a so that one serial port is provided. Further, two sets of serial data may be extracted from one row of data of the memory cell 29 by providing one set of the data register 30 and providing two sets of the data selector 31, the serial data buffer 32, and the address pointer 38.

The display memory is not limited to a case where color display data is converted into gray scale display data, but in other cases, for example, a gray scale for reducing display data of n gray scales to display data of m gray scales (n> m). The present invention can also be used for a conversion method, a color conversion method for reducing display data of n colors to display data of m colors (n> m), and the like.

In the above embodiment, when different colors are associated with the same gradation in adjacent display areas, a color boundary line is displayed on the display panel at a gradation different from the gradation by one step luminance. Although an example has been shown, the gradation may be different from one step to two or more steps in luminance. Further, even when different colors are associated with different gradations in adjacent display areas, the present invention may be applied to the purpose of clarifying the difference in gradation.

Further, the present invention can also be applied to a case where multi-gradation data is converted into display data having a smaller number of gradations.

In this case, the gradation conversion circuits 8a, 8b, 8c do not convert physical color data into gradation data, but convert multi-gradation data into low-gradation data. Then, it is detected whether or not the gradations of the adjacent areas are the same or similar. If so, the boundary line of the adjacent area is changed to a gradation of a luminance that can be distinguished from those areas.

Further, in the above embodiment, the case where color display data is converted into the corrected gradation data 14 has been described, but the present invention may be applied to conversion into color data having a smaller number of colors. Hereinafter, an embodiment in this case will be described with reference to FIG.

The basic configuration of this embodiment is based on the same concept as that of the first embodiment. Therefore, the description of the same components will be omitted, and the description will focus on the differences.

That is, in this embodiment, a color number reduction circuit is used instead of the gradation conversion circuits 8a, 8b, 8c in the first embodiment shown in FIG.
40a, 40b and 40c are used, and a color changing circuit 45 is used instead of the gradation changing circuit 17. 46 is a color display capable of displaying eight colors.

The number-of-colors reduction circuits 40a, 40b, and 40c provide 64 physical color data 10
This is a circuit for converting a, 10b, and 10c into eight physical color reduction data 41a, 41b, and 41c. Table 2 configures the 64 physical color data 10
The correspondence of colors in a method of taking the logical sum of each 2 bits of RGB and creating the physical color reduction data 41 of 8 colors consisting of 1 bit of each RGB is shown. Of course, the number of colors may be reduced by another method.

The physical color data 10a output from the palette circuit 7 is
The color number reduction circuit 40a converts the data into physical color reduction data 41a. The physical color data 10a is stored in the one-dot storage circuit 14 and the one-line storage circuit 15.

The one-dot left physical color data 10b output from the one-dot storage circuit 14 is converted into physical color reduction data 41b by the color number reduction circuit 40b, and is compared with the physical color data 10a by the comparison circuit 16a. On the other hand, the physical color reduction data 41b at the point one dot left is compared with the physical color reduction data 41a at the point to be displayed by the comparison circuit 16c. Comparison circuits 16a and 1
The output of 6c is input to the AND circuit 18a. AND circuit 18a
Means that when the logical value of the output of the comparison circuit 16a is "0" and the logical value of the output of the comparison circuit 16c is "1", that is, when the physical color data differs from the one dot left point and the physical color reduction data is the same, Outputs logical value "1".

Similarly, for the physical color data 10c of a point on one dot output from the one-line storage circuit 15, the comparison circuit 16
b, 16d, and the point to be displayed by the number-of-colors reduction circuit 40c are compared. When the physical color data is different and the physical color reduction data is the same, the logical value "1" is output from the AND circuit 18b.

Further, the OR of the outputs of the two AND circuits 18a and 18b is calculated by the OR circuit 19, so that a point to be displayed and one of the points are displayed.
When the physical color data of the dot on the left or on one dot is different and the physical color reduction data is the same, a color change request signal 42 having a logical value "1" is obtained.

By the way, when displaying the topmost line or the leftmost point on the display screen, there is no point one dot to the left or above the point to be displayed, so the color change request signal 42 obtained as described above is obtained. Is invalid. Therefore, a line count circuit that has a logical value “0” during the period in which the topmost line and the leftmost dot on the display screen are displayed
The logical product of the mask signal 22 from 20 and the color change request signal 42 is taken by an AND circuit 18c to create a color change signal 43. The reason that the color change signal 43 becomes the logical value “1” is that the color change request signal 21 becomes the logical value “1” during a period other than a period during which the uppermost line or the leftmost dot on the display screen is displayed. This is the case.

When the color change signal 43 has the logical value “1”, the color change circuit 45
The B3 bit physical color reduction data 41a is changed as shown in Table 3, and corrected physical color reduction data 44 is output. Of course, the corrected physical color reduction data 44 is the physical color reduction data 41a.
If the color is different from the color shown in the table, a color based on a correspondence other than that shown in the table may be used.

When the correction data color change signal 43 has the logical value “0”, the correction data color change data 43a is output as it is without changing the physical color reduction data 41a.

By using the corrected physical color reduction data 44 described above,
In a case where a different color in the adjacent display area before the color number reduction is associated with the same color after the color number reduction, a color boundary line is displayed on the display panel in a color different from the color. Can be. In this case, the color changing circuit 45 functions as a boundary line color changing unit, and executes the boundary line color change in response to the correction data color change signal.

It is preferable that the gradation (color) conversion method in each of the embodiments of the present invention described above is configured by integrating its components and forming an IC. In this case, an LSI may be used together with other circuits.

[Effects of the Invention] As described above, in the gradation conversion method of the present invention, when converting multi-color display data to gradation data, different colors are converted to the same gradation in adjacent display areas. If
Since the boundary of the color can be displayed in a gradation different from the above gradation, there is an effect that the boundary of the color can be easily recognized visually.

In addition, by using the triple port memory of the present invention, there is an effect that a one-line storage circuit such as a line memory can be deleted from the circuit of the gradation conversion method.

Further, in a line-top type information processing device using a display device corresponding to the present invention, since it is not difficult to see even when a conventional color application for a color CRT is operated, software compatibility can be maintained,
There is an effect that the user can use it with peace of mind.

[Brief description of the drawings]

1 and 2 are block diagrams showing a configuration of an embodiment of a gradation conversion system of the present invention, FIG. 3 is a block diagram of a triple port memory of the present invention, and FIG. FIG. 5 is a block diagram showing one configuration example of a pallet circuit 7, FIG. 6 is a logic circuit diagram showing one configuration example of a gradation conversion circuit 8, and FIG. 7 is a conventional dual-port memory. FIG. 8 is a block diagram showing an embodiment of the color conversion system of the present invention. 5: display memory, 7: palette circuit, 8: gradation conversion circuit, 9: logical color data, 10: physical color data, 11
…… Gradation data, 12 …… Panel display, 14 …… 1
Dot storage circuit, 15: 1 line storage circuit, 16: comparator, 17: gradation changing circuit, 20: line count circuit,
24: Corrected gradation data.

Claims (9)

(57) [Claims] 1. A gradation conversion method for converting color display data into gradation display data, comprising means for detecting that different colors are associated with gradations of the same or similar luminance in adjacent display areas. And a step of associating the gradation data having a luminance different from the gradation by one or more steps with a boundary of an adjacent display area detected to be correlated with a gradation having the same or close luminance by the detecting means. A means for forming a boundary line. 2. A gradation conversion method for converting color display data into gradation display data, comprising: means for gradation-converting color display data for a target region; and color conversion for a region adjacent to the target region. Means for converting display data into gradation data; comparing the target region and the region adjacent thereto with both color display data and comparing both gradations so that both display colors are different. And a means for detecting a state in which the gradation is converted to the same or similar luminance, and the detecting means converts the two display colors to different luminances with the same or similar gradation. A means for forming a boundary line of grayscale data of luminance identifiable with both regions at a boundary between adjacent regions in which a state has been detected. 3. A gradation conversion system for converting color display data into gradation display data, wherein the display data is included in a display line different from a display line including the point, together with logical color data of a point to be displayed. A display memory for simultaneously outputting logical color data of a point adjacent to the point, a pallet circuit for converting each of the two points of logical color data output from the display memory into physical color data, Means for converting color data into gradation data, means for converting physical color data into gradation data at an adjacent point on the same display line as the point at which the display is performed, and Means for converting physical color data into gradation data for points adjacent to the point to be displayed, and for points adjacent to the point to be displayed on a line adjacent to the point to be displayed. In addition, physical color data is compared for each point adjacent to the point on which the display is performed on the same line, and gradations are compared for these points, so that the display point and at least one of the two adjacent points are displayed. Means for detecting a state where the gradation is converted to the same or similar luminance despite different colors; and means for detecting the state, wherein at least one of a display point and two adjacent points is displayed. When a state is detected in which the gradation is converted to the same or similar luminance despite the different display colors, the luminance which can be distinguished from the region sandwiching the boundary is located at the boundary of the display region including each point. Means for forming a boundary line of the gradation data of the above. 4. A gradation conversion method for reducing display data of n gradations to display data of m gradations (n> m), wherein different gradations in the adjacent display areas are the same or close. Means for detecting the correspondence, and the boundary of the gradation in the n-gradation display data which is detected by the detection means to be correlated with the gradation of the same or similar luminance. Means for forming a boundary line of a gradation different from the attached gradation. 5. A color conversion method for reducing display data of n colors to display data of m colors (n> m), wherein different colors are associated with the same or similar colors in adjacent display areas. Detecting means for detecting that different colors have been associated with the same or similar colors in adjacent display areas by the detecting means. A color conversion method comprising: means for forming a boundary line of a color different from the color of the color. 6. A memory device, comprising two serial access ports capable of both reading data in addition to a parallel access port. 7. A gradation conversion system according to claim 3, wherein said display memory includes a memory element having two serial access ports capable of both reading data in addition to a parallel access port. 8. An information processing apparatus using the gradation conversion method according to claim 1, 2, 3, 4, or 7. 9. An information processing apparatus using the color conversion method according to claim 5.