JP3030862B2 - Display control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display control device for controlling color display on a color bit map display.

[0002]

2. Description of the Related Art Conventionally, in this type of apparatus, when displaying color characters on a color bit map display, the following two methods have been used.

1: For each character, a color bit pattern developed into a color expression bit number based on a character color and a background color is held in advance, and when displaying a character, a color bit pattern corresponding to a designated character code is stored. , From a group of color bit patterns stored in advance, and transfers the image to a color display frame buffer.

2: A character font image is stored as a monochrome font image, that is, one bit per pixel, and at the time of displaying a character, each bit data of the monochrome font image is converted into a color bit based on a character color and a background color for each pixel. Develop into a pattern and transfer this to the color display frame buffer.

[0005] Color characters are displayed on a color bit map display based on the color bit pattern transferred to the color display frame buffer in this manner.

[0006]

However, in the above conventional display control device, in the above method 1, color character display can be performed at a high speed, but the font image is stored as a color font image for each character. And required a lot of storage space. In particular, when the number of characters is enormous, such as in a multi-font or Japanese language, an extremely large storage area is required. Furthermore, since a color font image must be held for each combination of a character color and a background color, a large storage area is required. In order to perform color character display in this manner, a large amount of storage area is required, and memory resources cannot be used effectively.

On the other hand, in the above method 2, in order to hold a font image as a monochrome font image,
Although there is an advantage that a smaller storage area is required as compared with the above method 1, every time a character display request is generated, a monochrome bit pattern is developed into a color bit pattern for each pixel based on a character color and a background color. And the processing speed is slow.

The present invention has been made in view of the above circumstances, and has as its object to provide a display control device capable of improving the effective use of memory resources and improving the processing speed.

[0009]

In order to achieve the above object, the present invention relates to a display control device for controlling color display on a display means, wherein a bit pattern of a predetermined plurality of pixels represented by one bit per pixel is provided. Creating means for creating a color bit pattern group corresponding to all possible combinations and indicating a pattern reflecting the color information of the foreground color and the color information of the background color, and the color bit pattern created by the creating means Storage means for storing groups; read means for reading binary pattern data in units of the plurality of pixels; and color bit patterns corresponding to the bit patterns of the plurality of pixels read by the read means. And selecting means for selecting from among the following.

[0010]

According to the display control device of the present invention, color information of a foreground color and color information of a background color correspond to all possible combinations of bit patterns of a plurality of predetermined pixels represented by one bit per pixel. Is stored in the storage means.

When the binary pattern data is developed into a color bit pattern corresponding to the color information of the foreground color and the color information of the background color, the binary pattern data is converted into a predetermined pixel unit. And selects a color bit pattern corresponding to the read bit pattern of each of the plurality of pixels from the color bit pattern group. Thereby, the binary pattern data can be developed into a color bit pattern in units of a plurality of pixels.

[0012]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a block diagram showing one embodiment of a display control device according to the present invention.

In FIG. 1, the display control device includes a monochrome bit pattern processing section 1, a color bit pattern processing section 2, a color display frame buffer memory 3, a color video signal generation section 4, a color lookup table 5, and a color CRT 6. ing.

In the monochrome bit pattern processing section 1, when the character code determination section 11 specifies a character code corresponding to a character, the monochrome font image selection section 12
Determines address information indicating an area in which a binary character font (monochrome font image) corresponding to the character code is stored, and notifies the monochrome font image reading unit 13 of the address information.

Then, in the monochrome font image reading section 13 which functions as the above-described reading means, the monochrome font image holding section 14 outputs the monochrome font image (2 bits) represented by 1 bit per pixel based on the notified address information. (Value pattern data) is read out in a predetermined bit unit.

In the color bit pattern processing unit 2, when the foreground / background color designating unit 21 designates foreground color information and background color information, the cache validity judging unit 22
Determines whether the color information of the designated foreground and background colors matches the color information of the previously designated foreground and background colors, and notifies the cache pattern creation unit 23.

Then, in the cache pattern creating section 23 which performs the function of the creating means described above, if the notified determination result indicates that the information does not match, one pixel per pixel
A color bit pattern group corresponding to all possible combinations of bit patterns of a predetermined plurality of pixels represented by bits and indicating a pattern reflecting the color information of the foreground color and the color information of the background color (details will be described later). Create). On the other hand, if the information indicates that they match, the color bit pattern group is not created.

The created color bit pattern group is stored in a color line cache pattern holding unit 24 which functions as the above-mentioned storage means constituted by a cache memory.
Is held.

Color line cache pattern holding unit 2
The access to 4 is performed by regarding the monochrome bit pattern read in a predetermined bit unit as a positive number and using the positive value as an offset.

That is, when a bit pattern (monochrome bit pattern) corresponding to a plurality of pixels is read by the monochrome font image reading unit 13, the color line cache pattern selecting unit 25 which functions as the above-described selecting means is used by the bit pattern. The indicated bit data is regarded as a positive number, and this value is notified to the color line pattern transfer unit 26. This means that a color bit pattern corresponding to a monochrome bit pattern corresponding to a plurality of pixels is selected from a color bit pattern group.

The color line pattern transfer unit 26 accesses the color line cache pattern holding unit 24 using the notified positive value as an offset, and transfers the corresponding color bit pattern to the color display frame buffer memory 3.

When the color bit pattern is transferred to the color display frame buffer memory 3 as described above, the color video signal generator 4 periodically reads out pixel data from the color display With reference to the look-up table 5, a color video signal corresponding to the pixel data is generated. This color video signal is used as color information.
Color CRT6 which is a color bitmap display
Will be displayed.

Next, the above-described color bit pattern group will be described. In this embodiment, when the reading unit of the monochrome font image reading unit 13 is, for example, 4 bits, the color line cache pattern holding unit 24 is provided with 2 to the fourth power (16) entries. A result obtained by developing a monochrome 4-bit pattern (a 4-bit bit pattern corresponding to 4 pixels) into an 8-bit color bit pattern per pixel is held. FIG. 2 shows an example of the developed color bit pattern group.

In FIG. 2, reference numeral 241 denotes a monochrome bit pattern group consisting of monochrome bit patterns MP0 to MP15 indicating all combinations of monochrome bit patterns expressed by the read unit 4 bits of the monochrome font image reading unit 13; Is 8 bits per pixel, corresponding to each of the monochrome bit patterns MP0 to MP15 when the foreground color (10110101) and the background color (10100010) are 8 bits as color information, and 4 × 8 = 32
A color bit pattern group including bit color bit patterns (32-bit color line patterns) CP0 to CP15 is shown. Note that the color bit pattern C
P0 to CP15 are stored in areas corresponding to indexes 0 to 15, respectively.

In FIG. 2, the monochrome bit pattern group 241 and the color bit pattern group 242
A rectangle corresponds to bit data, and a filled rectangle (a rectangle with left diagonal lines, right diagonal lines, and horizontal lines) corresponds to bit data whose bit is ON, that is, “1”, and the other rectangles are “0”. "Bit data.

Here, at the time of creating a color bit pattern by the cache pattern creating unit 23, when developing from a monochrome bit pattern to a color bit pattern, as shown in FIG. , “0” is 8-bit “10100010” (background color), while “1” is 8 bits
As the bit “10110101” (foreground color), a 4-bit monochrome bit pattern is developed into a 4-bit × 8-bit = 32-bit color bit pattern (32-bit color line pattern).

For example, since the monochrome bit pattern MP1 shown in FIG. 2 is a bit pattern of "0001",
Color bit pattern CP1 corresponding to the pattern
Is expanded to “10100010” (background color) for the third pixel from the left of the monochrome bit pattern, and “10100010” for the rightmost pixel of the monochrome bit pattern.
110101 "(foreground color). Similar development is performed for other monochrome bit patterns.

The color bit pattern group thus developed is stored in the color line cache pattern holding unit 2.
4, the color information of the foreground and background colors and the color information specified by the foreground / background color specifying unit 21 are held in the color line cache pattern holding unit 24 during the same period.

Next, basic expansion processing of the display control device in the above configuration will be described with reference to the flowchart of FIG.

Here, the pattern to be displayed is character information, and the processing unit of the character display (character code, character color, background color) is 4 bits, for example, the character "R" expressed by 1 bit per pixel. A description will be given of a developing process in which a monochrome font image of "" is developed into a color display frame buffer memory 3 expressed by 8 bits per pixel.

The foreground color is the color of the character, the background color is the color of the background of the character, and the monochrome font image of the character "R" is, for example, as shown in FIG. It is assumed that the content is held in the memory. In FIG. 4, rectangles correspond to bit data, and rectangles filled with oblique lines on the left correspond to bit data whose bits are ON, that is, “1”, and other rectangles correspond to bit data of “0”. It corresponds to bit data.

First, when the color character "R" is displayed, the character code "82" of the character "R" is designated from the character code determination unit 11 to the monochrome font image selection unit 12, and at the same time, the cache validity is determined. The color information of the character color and the background color is designated from the foreground / background color designation unit 21 to the judgment unit 22. Here, text color (10110101), background color (101000
Suppose that 10) is specified.

Then, as shown in FIG. 3, the cache validity determination unit 22 to which the color information has been specified is transferred to the color line cache pattern holding unit 24 by the color information which is specified this time.
It is determined whether the color information is valid for the color information of the character color and the background color held in (step 101).

Here, when the designated character color and background color are the same as the character color and background color (color at the time of creating the cache) shown in FIG. 2, that is, the cached color information is valid. If there is (step 101: YES), the monochrome font image selection unit 12 stores the monochrome font image corresponding to this code based on the character code “82” specified by the character code determination unit 11. The address information indicating the area is determined and notified to the monochrome font image reading unit 13 (step 102).

Monochrome font image reading section 13
Reads the monochrome font image shown in FIG. 4 based on the notified address information from the monochrome font image holding unit 14, for example, in units of 4 bits (step 103).

Now, as shown in FIG. 5, when the pattern 51 of the monochrome font image is read, the color line cache pattern selecting section 25 reads out the data of the read 4-bit unit, that is, the monochrome bit pattern 51. The content ("0111") is regarded as a positive number, and the value is stored in ColorCash [INDEX] in the color line cache pattern holding unit 24 (step 1).
04).

Then, the color line pattern transfer section 26
The color line cache pattern holding unit 24 uses the value of the ColorCash [INDEX] as an offset.
And reads out the corresponding color bit pattern (32-bit color line pattern) and transfers it to the color display frame buffer 3 (step 105).

In this example, the positive value of “0111” is “7”, so that ColorCash [INDEX] is Color
Cash [7]. Therefore, in the color bit pattern group shown in FIG.
The color bit pattern CP7 stored in the area corresponding to the index 7 corresponding to [7] is read,
The data is transferred from the color line cache pattern holding unit 24 to a predetermined position in the color display frame buffer memory 3. Incidentally, the color bit pattern CP7 is (10100010101101011011010110110101101).

Next, after the end of step 105, the monochrome font image reading section 13 determines whether or not the reading process of the entire font pattern has been completed (step 106).

Here, if the processing has not been completed, the process returns to the step 103 and the steps after this step are executed.
When the processing is completed, the expansion processing for one character is completed. For example, when the development process of the character “R” is completed, a color font image of the character “R” to be displayed can be obtained. FIG. 6 shows the color font image.
In the figure, the color bit pattern surrounded by a bold frame (the area including the rectangle in which the horizontal line is painted) corresponds to the color bit pattern of the character color, and the portion other than that (the shaded area in the right diagonal line is painted). The area including the rectangle that is shown) corresponds to the color bit pattern of the background color.

Next, if the designation of the character color and the background color is not the same as the color at the time of creating the cache in step 101, that is, if the cached color information is invalid (step 101: NO), the cache pattern creating unit 23 is
A new color bit pattern group is created according to the color specification from the foreground / background color specification unit 21 and stored in the color line cache pattern holding unit 24.

That is, the cache pattern creation unit 23
Defines “CNT = 0” (step 107), and then determines whether or not the expression “CNT> 15” holds (step 108).

Here, if the above equation is not satisfied, the CNT
Is expressed in a binary system, and from the pattern expressed in the binary system, as shown in a color bit pattern group shown in FIG.
A color bit pattern (32-bit color line pattern) represented by a character color pattern at "1" and a background color pattern at "0" is created, and this pattern corresponds to ColorCash [CNT]. The data is stored in the area corresponding to the index (step 109), and then 1 is added to the CNT (step 110).

When storing the created color bit pattern, for example, when CNT = 1, Color
Since it is Cash [1], the index 1 corresponding to that value
In a region corresponding to the binary bit pattern (for example, the color bit pattern CP in FIG. 2) corresponding to the monochrome bit pattern of “0001” (for example, the monochrome bit pattern MP1 in FIG. 2) expressed in a binary system.
1) will be stored. By similar processing, C
A color bit pattern for the case where NT is 0, 2 to 15 is stored.

That is, the specification of the current color information is the character color (10110101), the background color (10100010), and the previous color information (ie, the color line cache pattern holding unit 2).
4 is different from the color information of the character color and the background color stored in the monochrome font image reading unit 13, the cache pattern creation unit 23 outputs the monochrome bit pattern represented by 4 bits, which is the reading unit of the monochrome font image reading unit 13. All combinations, ie, “0000”, “0001”,
.., For the 16 monochrome bit patterns represented by “1111”, the character color (10110101) corresponding to the bit data of “1”, and the background color (10100010) corresponding to the bit data of “0” ) Is developed to create a 4 × 8 = 32-bit color line pattern and further stored in the color line cache pattern holding unit 24.

In step 108, "CNT> 1
If the expression of “5” is satisfied, the process proceeds to step 102. At this time, the color line cache pattern holding unit 24 holds a color bit pattern group corresponding to a new combination of the character color and the background color. The color bit pattern (32-bit color line pattern) group is processed in the same manner as when the cached color information is valid, and the color display of the character “R” is performed.

In the above embodiment, when processing is performed in units of 4 bits, for example, the color character development and display of "R" can be performed 16 times, so that the character development reflecting the character color and the background color can be performed at high speed. Can be done.

According to the above embodiment, the cache validity determining unit 22 determines whether or not the cached color bit pattern group is valid.
From the group of color bit patterns cached in the color line cache pattern holding unit 24, a corresponding color bit pattern is selected. On the other hand, if the color bit pattern is invalid, it is created by the cache pattern creation unit 23.
From the new color bit pattern group cached in the color line cache pattern holding unit 24, the corresponding color bit pattern is selected, and the cached color bit pattern group can be used.

As described above, according to the present embodiment, no matter what combination of character color and background color is specified, it is only necessary to hold one monochrome font image for one character font. Can be used effectively. In addition, since the designation of the character color and the background color is often the same combination in succession, the cached color bit pattern group can be used as long as the same character color and the background color are designated. , High-speed color character display can be performed.

In the above embodiment, the display processing in the case of displaying a monochrome image of a character in color has been described. However, the present invention can be applied to the case of displaying a monochrome image of a figure in color.

In this case, the monochrome bit pattern processing section 1 shown in FIG. 1 is changed to a configuration in which a monochrome image of a figure is read in units of a plurality of bits corresponding to a plurality of predetermined pixels. The processing can be realized by performing the same processing as in the case of displaying characters.

[0052]

As described above, according to the present invention, a color bit pattern group corresponding to a designated foreground color and background color is created in advance, and the current foreground color and background color and the previous foreground color and background color are prepared. When the colors match, the corresponding specific color bit pattern is selected from the color bit pattern group, so that the development process from binary pattern data to the color bit pattern can be performed quickly. it can.

Further, since the pattern to be displayed can be stored as binary pattern data, it is possible to effectively use memory resources.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of a display control device according to the present invention.

FIG. 2 is a diagram showing an example of a color bit pattern group held in a color line cache pattern holding unit.

FIG. 3 is a flowchart showing an operation of developing a monochrome font image into a color bit pattern.

FIG. 4 is a diagram illustrating an example of a monochrome font image held in a monochrome font image holding unit.

FIG. 5 is an explanatory diagram for explaining a monochrome font image reading process.

FIG. 6 is a diagram showing an example of a color bit pattern stored in a color display frame buffer memory.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Monochrome bit pattern processing part 2 ... Color bit pattern processing part 3 ... Color display frame buffer memory 4 ... Color video signal generation part 5 ... Color lookup table 6 ... Color CRT 11 ... Character code judgment part 12 ... Monochrome font image selection Unit 13: Monochrome font image reading unit 14: Monochrome font image holding unit 21: Foreground background color designation unit 22 ... Cache validity judgment unit 23 ... Cache pattern creation unit 24 ... Color line cache pattern holding unit 25 ... Color line cache pattern Selection unit 26 ... Color line pattern transfer unit

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI G09G 5/36 G06F 15/68 (72) Inventor Manabu Fukushima 100-1 Sakado, Takatsu-ku, Kawasaki-shi, Kanagawa KSP R & D Business Park Building Fuji Xerox (72) Inventor Osamu Nakamura 100-1 Sakado, Takatsu-ku, Kawasaki, Kanagawa Prefecture KSP R & D Business Park Building Fuji Xerox Co., Ltd. (72) Inventor Masaki Yabu 100-1, Sakado, Takatsu-ku, Kawasaki, Kanagawa KSP R & D Business Park Building Fuji Xerox Co., Ltd. (56) References JP-A-61-283970 (JP, A) JP-A-61-283968 (JP, A) JP-A-61-284799 (JP, A) JP-A-62 123492 (JP, A) JP-A-62-215996 (JP, A) JP-A-62-255996 (JP, A) JP-A-63-21 694 (JP, A) JP-A-64-53271 (JP, A) JP-A-1-106281 (JP, A) JP-B 64-3273 (JP, B2) (58) Fields investigated (Int. Cl. ^7, DB name) G09G 1/00 G09G 3/00 G09G 5/00 G06F 3/00 G06T 5/00

Claims (1)

(57) [Claims] 1. A display control device for controlling a color display on a display means, wherein the foreground color corresponds to all possible combinations of bit patterns of a predetermined plurality of pixels expressed by one bit per pixel. Creating means for creating a color bit pattern group indicating a pattern reflecting the information and the color information of the background color; storing means for storing the color bit pattern group created by the creating means; Reading means for reading in units of a plurality of pixels; and selecting means for selecting a color bit pattern corresponding to the bit pattern of the plurality of pixels read by the reading means from the color bit pattern group. Display control device.