JP3184166B2 - Image processing apparatus and image processing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing apparatus and an image processing method, and more particularly, to an image processing apparatus and an image processing method for performing an image display process using character data and a palette table.

[0002]

2. Description of the Related Art Conventionally, this type of image processing apparatus has been widely used in portable games, pachinko liquid crystal display units, and the like, as disclosed in, for example, Japanese Patent Application Laid-Open No. Hei 5-317498.

FIG. 5 is a block diagram showing a configuration example of this conventional image processing apparatus. This conventional image processing apparatus
Palette RAM 1, character ROM 2, drawing means 3,
It comprises a CPU 4, an image buffer 5, a display controller 6, and a display 7.

The pallet RAM 1 stores in advance a pallet table in which RGB data of only display colors used for each pixel of a display image are set and registered as pallet data in correspondence with pallet codes.

A character ROM 2 stores character data obtained by converting RGB data of each pixel of a display image using a pallet code.

The drawing means 3 calculates the address of the character ROM 2 based on the setting data of the display image from the CPU 4, outputs a character ROM address signal to the character ROM 2, extracts each pixel data of the character data, and An address signal of the pallet RAM 1 is generated based on the pallet code and the setting data, output to the pallet RAM 1, pallet table conversion is performed, the pallet data is taken out, written and stored in the image buffer 5 as display RGB data of each pixel of the display image. Performs drawing control.

The CPU 4 outputs display image setting data to the drawing means 3, the image buffer 5 writes and stores display RGB data under the control of the drawing means 3, and the display controller 6 controls the image buffer. Display control is performed to sequentially retrieve the display RGB data stored in the display 5 and output it to the display 7, and the display 7 displays an image.

FIG. 6 is a flowchart showing a procedure for creating setting data, character data, and a pallet table used in the conventional image processing apparatus.

First, in step 51, in order to reduce the number of display colors used for each pixel of a display image, an allowable error range of RGB data to be the same color is set.

In step 52, RG of each pixel of the display image
The B data is fetched, and in step 53, it is determined whether pallet data is registered in the pallet table.

If pallet data is registered, step 5
In step 4, pallet data is extracted from the pallet table, and in step 56, the RGB data of each of the fetched pixels is compared with the pallet data to determine the inside and outside of the allowable error range.

If the error is out of the allowable error range, at step 58,
It is determined whether it is the last pallet data, and if it is not the last pallet data, the process returns to step S54.

If no pallet data is registered in step 53 or if it is the last pallet data in step 58, in step 59 the RGB data of the captured pixel is newly set as pallet data in the pallet table corresponding to the pallet code. register.

At steps 60 and 61, the pallet code set at step 59 is used, or at step 56
In this case, character data is created by converting the captured RGB data of each pixel using a pallet code corresponding to pallet data that falls within the allowable error range.

Further, the setting data of the display image is simultaneously created corresponding to the pallet table and the character data.

FIG. 7 shows the pallet RA created at this time.
FIG. 3 is a configuration diagram illustrating a configuration example of a pallet table stored in M1. Each of the RGB data of the pallet data is a pallet RAM address PA0-P corresponding to the pallet code.
An is set and registered.

FIG. 8 is an explanatory diagram for explaining the relationship among a display image, character data, and a pallet code in the conventional image processing apparatus.

Referring to FIG. 8, each pixel data of the character data at the center of FIG. 8 is created by the pallet code at the top of FIG. 8 corresponding to each pixel of the display image at the bottom of FIG.

FIG. 9 is a flowchart showing the operation of the conventional image processing apparatus. The operation will be briefly described with reference to FIGS.

First, in step 10, the CPU 4 outputs setting data of a display image to the drawing means 3.

At step 21, the drawing means 3 extracts each pixel data of the character data from the character ROM 2 based on the setting data. At step 26, the pallet code of each pixel data is stored in the palette based on the palette table of the palette RAM 1 and the setting data. Table conversion into data respectively to generate RGB data for display,
In step 28, the image data is written and stored in the image buffer 5 and drawn.

In step 30, the display controller 6 sequentially retrieves the display RGB data stored in the image buffer 5 and displays the image on the display 7.

In this conventional image processing apparatus, since the RGB data of each pixel of each character data corresponding to the display image is converted into a short word-length pallet code, the capacity of the character ROM for storing each character data in advance. Can be reduced.

[0024]

Problems with the conventional image processing apparatus include the following two points. 1. Since only the number of colors that can be displayed on the same screen can be displayed in the palette RAM, the expressive power is poor. 2. Since the same color, such as the sea and the mountain, having different shades must be registered as separate colors in the area of the palette RAM, the number of colors that can be registered decreases. At this time, when increasing the number of colors, the already registered pallet code is used instead, but there is a trade-off with expression power. The reason is that the character data constituted in the character ROM is constituted by one palette code per pixel, and only the number of colors of the number of palette data registered in the palette table of the palette RAM corresponding to the palette code is displayed. This is because they cannot.

Accordingly, it is an object of the present invention to improve the expressive power of a display image which differs only in shading or light and dark without increasing the capacity of the character ROM and the palette RAM.

[0026]

[0027]

[0028]

Therefore SUMMARY OF THE INVENTION An image processing apparatus of the present invention, one of RG to be used for each pixel on the display screen
The display color used for each pixel of the display image is based on the coefficient table in which each coefficient value indicating the correlation of each display color based on the B data is discretely set and registered corresponding to the coefficient code. Pallet table, which is set and registered corresponding to a pallet code, using one RGB data of each group as pallet data.
M and character data obtained by converting RGB data of each pixel of the display image using the pallet code and the coefficient code.
Each pixel data of the character data is stored in advance in the OM, and is extracted from the character ROM based on the setting data of the display image from the CPU, and the pixel data is separated into the pallet code and the coefficient code. Based on the coefficient table and the setting data, the pallet data and the coefficient value are respectively converted into tables and operated to generate display RGB data, which are written and stored in an image buffer for drawing.

Further , according to the image processing method of the present invention, each coefficient value indicating a correlation of each display color based on one RGB data used for each pixel on a display screen is discretely associated with a coefficient code. A coefficient table registered and set in advance is created in advance, an allowable error range of RGB data to be set to the same color is set, and the number of display colors used for each pixel of the display image is reduced based on the allowable error range, group to the coefficient table
Hazuki said classified into each group of each of the display colors are correlated, and the pallet table set registered in correspondence to the palette encodes one RGB data of each group as the pallet data, the pallet code and the coefficient code And character data obtained by converting the RGB data of each pixel of the display image.

A setting step of setting an allowable error range of RGB data to be the same color and storing the coefficient table; fetching RGB data of each pixel of the display image to determine whether palette data is registered in the palette table; A registration judging step of judging, and, if pallet data is registered, fetching pallet data from the pallet table, sequentially reading out each coefficient value from the coefficient table, calculating pallet data, and calculating the calculated data and RGB data of the fetched pixel. A comparison determination step to determine whether the pallet data is inside or outside the allowable error range.
A pallet table registration step of newly setting and registering the data as pallet data in the pallet table corresponding to the pallet code; and using the pallet code and the reference coefficient code set in the pallet table registration step, or If the step is within the permissible error range, a step of converting the RGB data of the captured pixel using the pallet code and the coefficient code corresponding to the pallet data and the coefficient value falling within the permissible error range, respectively, to create character data. And

[0031]

Next, the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the image processing apparatus of the present invention. The image processing apparatus of this embodiment includes a palette RAM 1, a character ROM 2, a drawing unit 3, a CPU 4, an image buffer 5, a display controller 6, and a display 7. In each of these blocks,
The CPU 4, the image buffer 5, the display controller 6, and the display 7 are the same as the respective blocks of the conventional image processing apparatus in FIG.

The palette RAM 1 discretely sets and registers each coefficient value indicating the correlation of each display color based on one RGB data used for each pixel on the display screen in correspondence with the coefficient code. Based on the table, the display colors used for each pixel of the display image are classified into respective groups of display colors having a correlation such as light and dark or light and dark, and one RGB data of each of these groups is paletted as palette data. Stores the pallet table that has been set and registered for each code.

The character ROM 2 stores character data obtained by converting RGB data of each pixel of a display image using a pallet code and a coefficient code.

The drawing means 3 extracts each pixel data of the character data from the character ROM 2 based on the setting data of the display image from the CPU 4, separates each pixel data into a pallet code and a coefficient code, Based on the table and the setting data, the table is converted into pallet data and coefficient values to calculate and generate display RGB data, which is written and stored in an image buffer for drawing.

The drawing means 3 further includes a control unit 31,
It includes a judgment unit 32 and a calculation unit 33.

The control unit 31 performs an address operation of the character ROM 2 based on the setting data of the display image from the CPU 4, outputs a character ROM address signal to the character ROM 2, extracts each pixel data of the character data, and based on the setting data. , Outputs the head address signal of the pallet table, and writes and stores the display RGB data in the image buffer 5 for drawing.

The judging section 32 judges whether or not the coefficient code of the character data is used or not according to the value of the head address signal.
Each pixel data of the character data extracted from the data is separated into a pallet code and a coefficient code, and the coefficient code is converted into a coefficient value based on the coefficient table and the start address signal, and is output. The reference coefficient value is converted and output as a numerical value.
1 is generated and output to the palette RAM1.

The calculating section 33 calculates palette data and coefficient values converted and output from the pallet RAM 1 and the judging section 32 corresponding to each pixel data of the character data, generates RGB data for display, and stores the image buffer. 5 is output.

FIG. 2 is a flowchart showing a procedure for creating setting data, character data, and a pallet table used in the image processing apparatus of this embodiment.

Here, 1 is used for each pixel on the display screen.
A coefficient table in which each coefficient value indicating the correlation of each display color based on one of the RGB data is discretely set and registered corresponding to the coefficient code is created in advance.

First, in step 51, the number of display colors used for each pixel of the display image is reduced and the same color is used to classify the display colors into the respective groups of display colors having a correlation in the coefficient table. An allowable error range of RGB data is set, and a coefficient table is stored.

In step 52, RG of each pixel of the display image
The B data is fetched, and in step 53, it is determined whether pallet data is registered in the pallet table.

If pallet data is registered, step 5
In step 4, pallet data is extracted from the pallet table. In step 55, each coefficient value is sequentially read from the coefficient table and calculated with pallet data. In step 56, the calculated data is compared with the RGB data of the fetched pixel and allowed. Judge inside and outside the error range.

If it is out of the allowable error range, in step 57,
It is determined whether it is the last coefficient value registered in the coefficient table, and if it is not the last coefficient value, the process returns to step 55. If it is the last coefficient value, it is further determined in step 58 whether it is the last pallet data. If it is not the pallet data, the process returns to step 54.

If no pallet data is registered in step 53 or if it is the last pallet data in step 58, in step 59 the RGB data of the captured pixel is newly set as pallet data in the pallet table corresponding to the pallet code. register.

In steps 60 and 61, the pallet code set in step 59 and the reference coefficient code are used.
Character data is created by converting the captured RGB data of each pixel using a palette code and a coefficient code corresponding to the palette data and the coefficient value within the allowable error range.

Further, the setting data of the display image is simultaneously created corresponding to the pallet table and the character data.

The configuration of the pallet table created at this time and stored in the pallet RAM 1 is the same as that of the conventional example shown in FIG.

FIG. 3 is an explanatory diagram for explaining the relationship between a display image, character data, and a pallet code in the image processing apparatus of this embodiment.

Referring to FIG. 3, each pixel data of the character data in the center of FIG. 3 is created by a pallet code and a coefficient code in the upper part of FIG. 3 corresponding to each pixel of the display image in the lower part of FIG. .

FIG. 4 is a flowchart showing the operation of the image processing apparatus of this embodiment. The operation will be described with reference to FIGS.

First, in step 10, the CPU 4 outputs setting data of a display image to the control unit 31 of the drawing means 3.

In step 21, the control section 31 extracts each pixel data of the character data from the character ROM 2 based on the setting data, and outputs a head address signal of a pallet table based on the setting data.
The determining unit 32 determines whether to use or not use the coefficient code of the character data based on the value of the head address signal.

If the coefficient code is used in step 22, the judging section 32 separates each pixel data of the character data extracted from the character ROM 2 into a pallet code and a coefficient code in step 23.
The determination unit 32 converts the coefficient code into a coefficient value based on the coefficient table and the head address signal, and outputs the result.

If the coefficient code is not used in step 22,
In step 25, the determination unit 32 converts and outputs a reference coefficient value as a coefficient value.

At step 26, the judgment unit 32 determines whether the palette RAM
1 is generated and output to the pallet RAM1.
The pallet RAM 1 converts and outputs pallet data corresponding to the pallet table.

In step 27, the calculating section 33 calculates the coefficient values and pallet data converted and output in steps 22 and 26, respectively, generates RGB data for display and outputs the data to the image buffer 5, and in step 28 The control unit 31 writes and accumulates the image in the image buffer 5 and draws the image.

In step 30, the display controller 6 sequentially retrieves the display RGB data stored in the image buffer 5 and displays the image on the display 7.

In the image processing apparatus of the present embodiment, by setting each coefficient value to a value indicating shading or light / dark based on one piece of RGB data, character data is changed using a pallet code and a coefficient code. If the word length is the same as in the prior art, the character ROM,
Without increasing the capacity of the palette RAM, it is possible to improve the expressive power of a display image that differs only in shading or brightness.
Further, when the number of colors including light and shade or light and dark, which can be displayed on one screen, is the same as that of the related art, the capacity of the palette RAM can be reduced.

For example, when m bits are assigned to a coefficient code in each pixel data of character data corresponding to an image, when the palette RAM capacity is the same as that of the prior art, colors of 2 m times are simultaneously displayed. When the number of colors is the same as in the prior art, the capacity of the palette RAM can be reduced to 1 / m 2.

Since the character data and pallet table corresponding to the coefficient code and the character data and pallet table of the prior art can be distinguished by the value of the head address signal of the pallet table stored in the pallet RAM, the character ROM, Since the display image can be mixed and stored in the palette RAM and the display image can be synthesized from the character data and the palette table respectively created corresponding to the plurality of images based on the setting data, as in the related art, the display image can be expressed. Strength can be improved.

As a modification of the image processing apparatus according to the present embodiment, each coefficient value is set to a magnification value or a difference value based on one RGB data, and the coefficient table is set with the reference coefficient value being 1 or 0. Obviously, an image processing device that creates and performs multiplication or addition / subtraction in the operation unit is realized. Further, each coefficient value is set to a value set and registered for R, G, and B, and the coefficient table is set. Obviously, an image processing device that creates and performs calculations in the calculation unit is realized.

[0063]

As described above, in the image processing apparatus of the present invention, character data is composed of pallet codes and coefficient codes, and pallet data and coefficient values are calculated to generate display RGB data. You can display colors other than those registered in the palette table. Therefore, when the word length of the character data is the same as that of the conventional technology, the capacity of the character ROM and the palette RAM is not increased, and the expressive power of a display image different only in shading or light and dark can be improved. Alternatively, when the number of colors including light and dark is the same as that of the conventional technology, the capacity of the palette RAM can be reduced.

Further, character data and a pallet table corresponding to the coefficient code and the character data and the pallet table of the prior art can be stored in the character ROM and the pallet RAM in a mixed manner. Since the display image can be synthesized from the character data and the pallet table created corresponding to the plurality of images, the expression of the display image is improved.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an embodiment of an image processing apparatus according to the present invention.

FIG. 2 is a flowchart showing a procedure for creating setting data, character data, and a pallet table used in the image processing apparatus of FIG. 1;

FIG. 3 is an explanatory diagram for explaining a relationship among a display image, character data, and a pallet code in the image processing apparatus of FIG. 1;

FIG. 4 is a flowchart showing an operation of the image processing apparatus of FIG. 1;

FIG. 5 is a block diagram illustrating a configuration example of a conventional image processing apparatus.

6 is a flowchart showing a procedure for creating setting data, character data, and a pallet table used in the image processing apparatus of FIG. 5;

FIG. 7 is a configuration diagram showing a configuration example of a pallet table stored in a pallet RAM1.

FIG. 8 is an explanatory diagram for explaining a relationship among a display image, character data, and a pallet code in the image processing apparatus of FIG. 5;

FIG. 9 is a flowchart showing an operation of the image processing apparatus of FIG. 5;

[Explanation of symbols]

 Reference Signs List 1 palette RAM 2 character ROM 3 drawing means 4 CPU 5 image buffer 6 display controller 7 display 10 to 61 steps

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G09G 5/02 G06T 1/00 G09G 5/06

Claims (11)

(57) [Claims] 1. One R used for each pixel on a display screen
A display color used for each pixel of a display image is determined based on a coefficient table in which each coefficient value indicating a correlation of each display color based on GB data is discretely set corresponding to a coefficient code and registered. In each of the groups consisting of the display colors, and one RGB of each of these groups.
A pallet table is created by setting the data as pallet data and registering the pallet table corresponding to the pallet code.
AM, and character data obtained by converting the RGB data of each pixel of the display image using the pallet code and the coefficient code, respectively, is stored in the character ROM in advance, and the display image setting data from the CPU is stored. Each pixel data of the character data is extracted from the character ROM based on the pallet code and the coefficient code, and the pixel data is separated into the pallet code and the coefficient code. An image processing device that converts each table into a numerical value, performs calculation, generates RGB data for display, writes and stores the data in an image buffer, and draws the image. 2. The method according to claim 1, wherein each of the coefficient values is a value indicating light and dark or light and dark based on one piece of RGB data.
The image processing device according to claim 1. 3. The image processing apparatus according to claim 1, wherein each of the coefficient values is a magnification value based on one piece of RGB data, and the reference coefficient value is 1. 4. The image processing apparatus according to claim 1, wherein each of the coefficient values is a difference value based on one piece of RGB data, and the reference coefficient value is 0. 5. The method according to claim 1, wherein each of the coefficient values comprises a value set and registered for each of R, G, and B.
5. The image processing apparatus according to 2, 3, or 4. 6. One R used for each pixel on a display screen
A coefficient table in which each coefficient value indicating the correlation of each display color based on the GB data is discretely set corresponding to the coefficient code is created in advance, and an allowable error range of the RGB data for the same color is set. Then, the number of display colors used for each pixel of the display image is reduced based on the permissible error range, and the display colors are classified into groups each including the display colors having the correlation based on the coefficient table. The RGB data of each pixel of the display image is converted using the pallet table in which one RGB data of each group is set and registered as pallet data corresponding to the pallet code, and the pallet code and the coefficient code. An image processing method for creating character data. 7. A setting step of setting an allowable error range of RGB data to be the same color and storing the coefficient table, fetching RGB data of each pixel of the display image, and determining whether palette data is registered in the palette table. A registration judging step of judging, and, if pallet data is registered, fetching pallet data from the pallet table, sequentially reading out each coefficient value from the coefficient table and calculating pallet data, and calculating the calculated data and the RGB data of the fetched pixel. A comparison judgment step of judging the inside and outside of the permissible error range; and in the registration judgment step or the calculation judgment step, if no pallet data is registered or if the pallet data is out of the permissible error range, the fetched RGB data of the pixel is set as pallet data as pallet data. New pallet table corresponding to code Using a pallet table registration step for setting and registering, and a pallet code and a reference coefficient code set in the pallet table registration step, or
If the calculated error is within the allowable error range, the RGB data of the captured pixel is converted by using the pallet code and the coefficient code corresponding to the pallet data and the coefficient value falling within the allowable error range to convert the character data. 7. The image processing method according to claim 6, further comprising the step of: 8. Each of the coefficient values comprises a value indicating light and dark or light and dark based on one piece of RGB data,
The image processing method according to claim 6. 9. The image processing method according to claim 6, wherein each of the coefficient values is a magnification value based on one piece of RGB data. 10. The method according to claim 6, wherein each of the coefficient values comprises a difference value based on one piece of RGB data.
10. The image processing method according to 8 or 9. 11. The image processing method according to claim 6, wherein each of the coefficient values is a value set and registered for each of R, G, and B.