JPH0299989A - Color map rewriting system - Google Patents

Abstract

PURPOSE:To easily rewrite a color map over a look at a display screen without exerting any influence upon a current display color by switching and using two color map tables. CONSTITUTION:A variation quantity DELTARGB is added to color data (current value) to be requested to change among color map data in a color map table memory 12 specified by a color map address register 25 every time a specific button switch at a switch part 13 is operated once, and when the sum value exceeds a maximum value, the value is changed into a value 0. Further, when a request to exert no influence upon the current display color is made, color map data on a color to be displayed next is taken out the color map table differently from color map data on other colors and used. Thus, the color map is easily rewritten and even if the color map is rewritten for the color to be displayed next as to the color map table 12-0, there is no influence upon the current display.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a display device equipped with a color map table that determines display colors, and particularly relates to a color map rewriting device suitable for rewriting a color map table. Regarding the method.

(Prior Art) In a display device equipped with a color map table, such as a graphic display device, the color map table is rewritten by inputting a color map rewriting command from the host computer or keyboard, and then executing R (red) according to the parameters of the command. ), G (green), B(
This was generally done by setting the intensity of blue) in a color map table. The setting result, ie, the color map rewriting result, is output to the monitor.

At this time, the colors currently displayed on the monitor will be affected.
It will change.

(Problems to be Solved by the Invention) In the conventional color map rewriting method, there was a problem in that when a color map rewriting command was input, the colors that had been used up until then were also affected.

Therefore, the problem to be solved by the present invention is to make it possible to rewrite a color map without affecting the currently used colors.

[Structure of the Invention] (Means for Solving the Problems) The present invention provides a first color map table for determining display colors, and a second color map table having the same contents as the first color map table in an initial state. and a table specification bit for specifying either the first or second color map table, and a table address for specifying the address of the first or second color map table specified by this table specification bit. A frame memory for storing a frame memory pattern consisting of a frame memory pattern, and a frame memory pattern to which a table specification bit for specifying a first color map table is added to the pattern corresponding to the table address specific to the next color to be displayed, and a frame. A pattern match detection means that sequentially compares all frame memory patterns stored in the memory to detect whether or not there is a pattern match; and a color map table switching means for changing the table designation bit in the memory pattern to a second color map table designation state, and accessing the first color map table using the pattern specific to the next color to be displayed. The feature is that the color map is rewritten.

(Function) According to the above configuration, the table address part of the frame memory pattern for each pixel of the frame memory matches a pattern specific to the next color to be displayed, and the table designation bit matches the pattern specific to the first color. For any frame memory pattern that specifies a map table, its table designation bit is changed to the second color map table designation state. As a result, when the frame memory is scanned and the frame memory patterns are sequentially read out, and the screen is displayed by referring to the first or second color map table based on the readout pattern, the pixels for which the pattern matching is detected will be displayed in the second color map table. Color display is performed based on the data in the color map table, and other pixels are displayed in color based on the data in the first color map table. At this time, since the contents of the first and second color map tables are the same, there is no difference in color from the case where the screen display is performed by referring only to the first color map table. Therefore, in this state, by accessing the first color map table and rewriting the color map using a pattern specific to the next color to be displayed, it becomes possible to rewrite the color map without affecting the colors being displayed.

(Embodiment) FIG. 1 is a block diagram showing an embodiment of a color map rewriting mechanism to which the present invention is applied, and 11 is a frame memory for storing images to be displayed on a color display monitor (not shown). be. The image data (frame memory pattern) for each pixel of the image stored in the frame memory 1 has a 5-bit structure, which is 1 bit more than the conventional one. Reference numeral 12 denotes a color map table memory 2 which is accessed using a frame memory pattern read from the frame memory 1 as an address and outputs color data (color map data indicating the intensities of R, G, and B) corresponding to the same pattern. be.

The color map table memory 2 stores two color map tables 12-0.1 of the same size as shown in FIG.
2-1. Color map tables 12-1 and 12-2 can be specified by the most significant bit (MSB) of a 5-bit address (address of color map table memory 12) as shown in FIG. Map table 12-0 is MS
When B=1, each color map table 12-1 is designated. The color map tables 12-0.12-0 have the same contents in the initial state. On the other hand, the frame memory 11 has five bitmap memory planes 110.
~11-4, each memory plane 11-0~11
-4 concatenated data of bit data at the same pixel position (the bit data of memory plane 11-o is BSB), that is, the frame memory pattern is color map table memory 1
Specify address 2. The MSB of this frame memory pattern specifies either the color map table 12-o or 12-1. Also, the remaining 4
The bit is a pattern specific to the display color and indicates a relative address within the color map table 12-j (i=1.2). As is clear, when the MSB of the frame memory pattern is "0", by rewriting the MSB of the same pattern to "1", the color map used for color display can be changed from the color map table 12-0 to the color map table 12-0. -1.

Referring again to FIG. 1, reference numeral 13 denotes a switch section 1 having several button switches (not shown) that are operated by the user to give instructions necessary for rewriting the color map.
Reference numeral 4 denotes a control section that performs color map rewriting control in accordance with instructions from the switch section 13.

Hereinafter, color map rewriting under the control of the control section 14 will be explained with reference to the flowchart of FIG. 3 as appropriate.

In this embodiment, the switch unit 13 stores R and G information for the color map of the currently used colors.

A button switch for specifying whether or not to change the intensity of B (that is, rewrite the color map), its R and G.

A button switch for specifying a change between changes in B, and a button switch for specifying whether or not to have an effect on the colors displayed on the display monitor by rewriting the color map (none of them are shown). is available.

When the user intends to rewrite the color map, he first operates a specific button switch on the switch unit 13 to instruct whether or not the rewriting is to affect the colors currently displayed on the display monitor. As a result, the control unit 14
If the determination in step S1 in FIG. 3 is made and the color map rewriting that does not affect the currently displayed color is instructed, the next display color input field shown in FIG. 15, and input a 4-bit frame memory pattern PAT (NXT
) is generated using the frame memory pattern generator 16 (4 bits) (step S2).

Next, the control unit 14 controls the frame memory address counter 1.
7 is set to an initial value of 0 as a counter value (frame memory address value) TMP (step S3). Then, the control unit 14 checks whether the TMP indicated by the frame memory address counter 7 is less than or equal to the final address of the frame memory 1 (step S4). If the determination in step S4 is YES, the control unit 14 selects TMP indicated by the counter 17 using the selector 18 and sets it in the frame memory address register 19, so that the TMP indicated by the counter 17 is set in the frame memory read register 20 from the frame memory 11.
Then, the 5-bit frame memory pattern PAT (TMP) at the pixel position indicated by TMP is read out (step S5).

Frame memory pattern FA read into register 20
T (TMP) is supplied to one input of comparator 2. The other input of this comparator 21 is a frame memory pattern PAT (NXT) unique to the next display color generated by the frame memory pattern generator 16, or 1-bit data with a value of "0" is added to its upper part. Supplied as is. The comparator 21 compares both the patterns PAT (NX
T) Compare PAT (TMP) and output a logic “1” signal if they match, and a logic “0” signal if they do not match.
Outputs the signal. The signal of the comparator 21 (coincidence/mismatch detection signal) is replaced with the MSB of FAT (TMP) and supplied to the frame memory write register 22.

When a pattern match is detected by the comparator 21, the control unit 14 transfers the frame memory pattern (5 bits) in which the MSB is replaced with the output signal of the comparator 21 to the TMP position indicated by the frame memory address register 19 (i.e., (original position) via the frame memory write register 22 (steps S6 to S7). That is, when a pattern match is detected by the comparator 21, the MSB of the frame memory pattern FAT (TMP) in the frame memory 11 specified by TMP (i.e., the memory plane 11-
The bit corresponding to 0) is rewritten from “O” to “1”.

After completing step S7, the control unit 14 counts up the frame memory address counter 17 and sets the TMP.
is incremented by 1 (step S8), and the process returns to step S4. Further, if a mismatch is detected by the comparator 21,
The control unit 14 skips step S7 and proceeds to step S8.
Perform the +1 operation and return to step S4. And TM
The loop of steps 84 to S8 is repeated until P exceeds the final address (maximum address) of the frame memory 11.

As described above, according to this embodiment, if it is determined in step S1 that color map rewriting that does not affect the color being displayed is instructed, the frame memory pattern FAT (NXT) of the next display color and the frame memory pattern FAT (NXT) of the next display color are memory 11
All frame memory pattern FAT (TMP) or 1
They are sequentially compared pixel by pixel, and if the patterns match, the MSB of the FAT (TMP) is rewritten to "1". As a result, the TP whose MSB is rewritten to “1”
The color map referenced by the pattern FAT (TMP) at the M position is from table 12-0 to table 12-
It will be switched to 1. In this case, table 12
-0.12-1 has the same content, so there is no change in the displayed color.

On the other hand, if there is an instruction to rewrite the color map that may affect the colors being displayed, the control unit 14 performs step S1.
Proceeding to step S9, the target of color matsubu rewriting,
That is, it is determined whether the color to be changed is the currently displayed color (the next displayed color). This determination is based on the switch unit 1
This is done based on the state of the specific button switch No. 3.

First, when there is an instruction to change the displayed color, the control unit 14 displays on the screen a cursor that can be moved on the display screen to indicate the position of the color map rewriting target color in response to the user's operation. The user performs the above-mentioned movement operation of the cursor, and when the cursor is moved to the display position of the color to be changed, the user operates the specific button switch of the switch section 13. When the control unit 14 detects the above operation, the control unit 14 inputs the X and Y coordinate values of the display position of the cuffle at that time to the coordinate input unit 23.
The address of the frame memory 11 corresponding to the same coordinate value is generated using the frame memory address generator 24 (step S11).
.

After completing step Sll, the control unit 14 reads the corresponding frame memory pattern from the frame memory 11 using the frame memory address generated by the frame memory address generator 24, and uses this pattern to read the corresponding color from the table memory 12. Read the map data (step S L2).

The specific operation of step SL2 is as follows.

First, the control unit 14 controls the frame memory address generator 24
By selecting the frame memory address generated by the selector 18 and setting it in the frame memory address register 19, the frame memory pattern of the display position of the color to be changed is transferred from the frame memory 11 to the frame memory read register 20. Read out. Next, the control unit 14 sets the frame memory pattern read in the frame memory read register 20 in the color map address register 25, thereby transferring the frame memory pattern from the color map table memory 12 to the color map read/write register 25.
In step 6, color map data (data indicating the color to be changed) specific to the frame memory pattern is read out.

Next, if the color map for the currently displayed color is not to be rewritten, the control unit 14 reads out the color map data of the corresponding next display color from the color maptable memory 12 using a 7-frame memory pattern specific to the next display color. (Step 513). This step SL3 is also performed when color map rewriting that does not affect the colors being displayed is specified and the process is extracted from the loop of steps 84 to S8.

When the control unit 14 executes step SL2 or step SI3, the amount of change ΔRGB for changing the color map is
(initial setting amount) is input using the ΔRGB input section 27 (step 514). Next, the control unit 14 controls the switch unit 1
Based on the state of step 3, it is checked whether R, G, or B color map change is requested, and whether the end of color map change is instructed (steps 815 to 18).
If the color map change is not completed, the requested color element (
Preparation processing for changing the color map for R, G, or B) is performed as follows (steps SL9 to SL521).

That is, the control unit 14 performs step SL2 or step Si.
Among the color map data read out to the color map read/write register 26 in step 3, color data (color intensity) corresponding to the requested color element is taken out to one input of the adder 28. The change amount ΔRGB inputted from the ΔRGB input section 27 is led to the other input of the adder 28, and ΔRGB is thereby added to (the current value of) the color data to be changed from the register 26.

When the control unit 14 finishes the preparation process for changing the color map described above, the color element to be changed remains unchanged.
If the color map change is instructed by operating the predetermined button switch of the switch unit 13 twice (step S22.323), first, the addition result of the adder 28 is changed to the predetermined maximum value of color intensity (here Then 100)
It is checked whether it exceeds (step 524). If the addition result of the adder 28 does not exceed the maximum value, the control unit 14 selects this addition result using the selector 29 and writes it back into the original color data field of the register 26.
Thereafter, the contents of the original address of the color map table memory 12 are rewritten with the contents of the register 26 (color map data) (step 525). On the other hand, if the addition result of the adder 28 exceeds the maximum value, the control unit 14 selects a predetermined value 0 by the selector 29 and writes it back to the original color data field of the register 26, and then The contents of the original address of the color map table memory 12 are rewritten with the contents of 26 (step 826).
). When step S25 or step 82B ends, the process returns to step S15.

As described above, in this embodiment, in a state where R, G, or B color data change is requested, the switch part I3
Every time a predetermined button switch is operated once, the color data (current value) of the color map data in the color map table memory 12 specified by the color map address register 25 changes to (the current value of) ■ΔRG.
If B is added and the added value exceeds the maximum value, the value is 0
will be changed to That is, in this embodiment, the color map can be easily rewritten to a desired amount of change by repeating switch operations. In addition, if it is requested that the color being displayed is not affected, the color map data for the next color to be displayed, which is different from the color map data for other colors, is extracted from the color map table 12-1 and displayed on the screen. Therefore, even if the color map of the color map table 12-0 is rewritten for the next color to be displayed, the color being displayed will not be affected.

[Effects of the Invention] As detailed above, according to the present invention, by switching and using two color map tables, it is possible to easily rewrite the color map while looking at the display screen without affecting the currently displayed color. It can be carried out.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a diagram showing the correspondence between the frame memory 11 and color map table memory 12 shown in FIG. 1, and FIG. 3 explains the operation. This is a flowchart for 11... Frame memory, 11-0 to 11-4... Bit map memory plane, 12... Color map table memory, 12-0.12-1... Color map table, 13... Switch section, 14...control unit, 2
1... Comparator, 28... Adder.

Claims (1)

[Claims] a first color map table for determining display colors;
In the initial state, a second color map table with the same contents as the first color map table, a table specification bit for specifying either the first or second color map table, and a table specification bit specified by this table specification bit. a frame memory for storing a frame memory pattern consisting of a table address for specifying the address of the first or second color map table; pattern matching detection means for sequentially comparing the frame memory pattern to which the table designating bit for specifying one color map table is added with all the frame memory patterns stored in the frame memory to detect whether or not there is a pattern match; and color map table switching means for changing the table designation bit in the corresponding frame memory pattern of the frame memory to the second color map table designation state each time a match is detected by the pattern match detection means. . A color map rewriting method, characterized in that the first color map table is accessed using a pattern corresponding to the table address specific to the color to be displayed next, and the color map is rewritten.