JPH05204351A - Color image display method - Google Patents

Abstract

PURPOSE:To execute image effect such as fade-in/out, cross fade and glow for plural images without increasing bitmap capacity and display circuit scale. CONSTITUTION:A color lookup table (CLUT X) 221 is synthesized from a 201 and a 211 with arithmetic process. A bitmap X 222 is similarly synthesized from a 202 and a 212 with arithmetic process. A synthetic image is displayed by using the CLUT X 221 and the bitmap X 222. Image effect switching in displayed synthetic image with high quality is executed by changing color data in the 221 synthesized by arithmetic process with a time function.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to display of a color image using a color look-up table (hereinafter abbreviated as CLUT), and more particularly, to a color image display method for switching and displaying a plurality of images. Regarding

[0002]

2. Description of the Related Art In a digital color image display method, the brightness level of each of the three primary colors of R (red), G (green) and B (blue) is used as n-bit color data to express 2 3nth power. .. A method of holding color data for each pixel of a display image and performing color display requires a display memory of 3n bits per pixel.

On the other hand, the amount of information per pixel is m
As a bit color code, the color display method using the CLUT is a method of converting the color code into R, G, and B luminance levels by a CLUT and expressing the m-th power of 2 colors. In this display method, a display image is configured from a CLUT and a bitmap that is a set of color codes corresponding to each pixel. Of these, the information amount of the bitmap is proportional to m. The color code is reduced, and the color codes are R, G,
By changing the CLUT for converting to the B brightness level, there is an advantage that the display color can be easily changed even with the same bitmap data.

In order to display a plurality of images simultaneously by a display method in which the number of colors that can be displayed is limited, the color code data is divided into a plurality of blocks, one image is assigned to each block, and a CLUT is set in block units. There has been an attempt to simultaneously display a plurality of images by operating them. An example of such a display method is disclosed in Japanese Patent Laid-Open No. 3-61.
There is one described in Japanese Patent Publication No. 995.

[0005]

In the above-mentioned display method of the prior art, the color code data is divided into a plurality of blocks in the depth direction, one image is assigned to each block, and the CLUT is switched to thereby change the bitmap. Part of the area is shown in a different image.

However, in order to superimpose and display a plurality of images to be displayed, one of the CLUT numbers must be transparent. Further, since the color code is assigned to each image in the depth direction, the number of colors that can be used is limited to the factorial of 2. Moreover, since a plurality of images are always displayed in an overlapping manner, there is a problem that image effects such as fade-in, fade-out, crossfade, and glow cannot be performed. In addition, a special display circuit is required to synthesize the bitmap on the display memory.

The present invention has been made in view of the above problems of the prior art. Therefore, the object of the present invention is not to increase the bit map capacity and the display circuit scale. An object of the present invention is to provide a color image display method capable of displaying image effects such as fade-in, fade-out, cross-fade, and glow on a plurality of images.

[0008]

In the present invention, independent n
N (n is a natural number) original image data is used to independently create n combinations of bitmaps and CLUTs, and a composite bitmap is created by combining color codes for each pixel at the same display position of the n bitmaps. A composite CLUT is created by combining the above n CLUTs, and the above composite bitmap is combined into a composite CLUT.
The above object was achieved by displaying using a LUT.

Here, the composite CLUT is composed of an n-dimensional color code array and has an i-th dimension (i is a natural number of n or less).
A color code array in which the number of color codes, which is the number of elements of the eye, is greater than or equal to the number of color codes in the i-th CLUT, and the product of the number of color codes in each dimension of the color code array is less than or equal to the CLUT limited color number To do.

Alternatively, the independent n original image data are regarded as one original image data having 3n-dimensional color data, and a representative color having 3n color data is determined for one color code. A bitmap corresponding to that is created, and at the time of display, the bitmap is displayed by a CLUT created by extracting three color data from each color code of the representative color.

In addition, c created from the first original image data
A first bitmap and a first CLUT each of which has a color code of c (where c is a natural number equal to or less than the CLUT limited color number)
And a second original image data is prepared, and a second original image data histogram is created for each color code of the first bitmap at the same display position as the second original image data. A CLUT is created, and a second bitmap is created using this second CLUT.
First CLUT and second CLU for the bitmap of
The mixed color data of T is used.

Further, in order to enhance the visual effect, a period for displaying a bitmap and a CLUT created from one original image data is provided before and after the image effect.

[0013]

By efficiently selecting the CLUT corresponding to a plurality of images and assigning the closest color as the color code to generate the bitmap, the deterioration of the quality of the displayed image can be suppressed as much as possible. By assigning arbitrary color data of one image as color data corresponding to this color code, the bitmap displays the one image.

Further, by allocating color data of a plurality of images mixed at a constant ratio as the color data of the CLUT, the image display in which the bitmaps overlap each other is displayed. Further, by continuously switching the CLUTs generated by setting the mixing ratio of the color data stepwise, it is possible to perform crossfade switching in which two images are switched while overlapping each other.

In addition, R (red), G (green), B (blue) 3
In a display device including planes, each having a CLUT, a bitmap synthesized from a plurality of images is stored for each plane, and the CLUT is switched to display an arbitrary one image or an overlapping image of a plurality of images. ..

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a principle diagram showing how a composite image is created from two independent types of images by a color image display method as an embodiment of the present invention.

In FIG. 1, an original image A100 is a monochrome bitmap area 101 composed of pixels of a color code Aa.
And a monochromatic bitmap area 102 composed of pixels of the color code Ab, and the original image B110 is composed of monochromatic bitmap areas 111 composed of pixels of the color code Ba and monochromatic bits composed of pixels of the color code Bb. Map area 11
It consists of two.

Further, in the figure, a composite image X120 is an image obtained by combining the original image A100 and the original image B110, and the monochrome image bitmap areas 121, 122, 12 are shown.
It is composed of four monochrome color bitmap areas 3,124.

The monochromatic bitmap area 121 is a combination of the intersections of the monochromatic bitmap area 101 and the monochromatic bitmap area 111, and is composed of pixels of a color code ABa in which a color code Aa and a color code Ba are combined. ..

The monochromatic bitmap area 122 is a combination of the intersections of the monochromatic bitmap area 101 and the monochromatic bitmap area 112, and is composed of pixels of a color code ABb which is a combination of the color code Aa and the color code Bb. ..

The monochrome bitmap area 123 is a combination of the intersections of the monochrome bitmap area 102 and the monochrome bitmap area 111, and is composed of pixels of a color code ABc, which is a combination of the color code Ab and the color code Ba. ..

The monochrome bitmap area 124 is a combination of the intersections of the monochrome bitmap area 102 and the monochrome bitmap area 112, and is composed of pixels of a color code ABd, which is a combination of the color code Ab and the color code Bb. ..

As described above, the color code forming each single-color bitmap area of the composite image X120 is created by combining the two color codes forming each single-color bitmap area of the original two images. Therefore, if the color data corresponding to the color code of the original image A100 is used as the CLUT for converting the color code forming each single-color bitmap area of the composite image X120 into the actual color data, the composite image X120 is obtained.
It is possible to display each single-color bitmap area of the same color as the same area of the original image A100, and vice versa.
If the color data corresponding to the 10 color codes is used, the original image B
It is possible to display the same color as the same area of 110.

A method for performing crossfade switching between two independent original images A100 and B110 using one combined image X120 based on the image data shown in FIG. 1 will be described below. For crossfade switching,
An example will be described in which the transition from the original image A100 to the original image B110 is made in accordance with a time lapse t (0 ≦ t ≦ 8) in eight steps.

The crossfade switching is a display system in which two images are displayed in an overlapped manner, during which one image component is attenuated and the other image component is increased and gradually switched. The image component referred to here is color data represented by the R, G, and B luminance levels of each pixel of the image.

When a certain brightness level x linearly changes from the brightness level x1 to the brightness level x2 in n steps according to the time t (0≤t≤n), the brightness level x (t) is described as in equation 1. can do. x (t) = {(x2-x1) ÷ n} × t + x1 (Equation 1)

Here, the color codes ABa and A forming the bitmap of the composite image X120 during the crossfade switching.
The color data corresponding to Bb, ABc, and ABd are represented by Xa (t), Xb (t), Xc (t), and Xd (t) (not shown), respectively. That is, the composite image X12
0 monochrome color bitmap areas 121, 122, 1
23 and 124 are Xa (t), Xb (t), and Xc, respectively.
It is displayed as color data of (t) and Xd (t).

Further, the original image A100 and the original image B11
Color codes Aa, Ab, B that compose a 0 bitmap
Specific values of color data corresponding to a and Bb are shown in FIG. 2 as an example.

In the figure, color codes Aa and Ab are parts of the CLUT of the original image A100, and (R, G, B) = (128, 32, 0), (R,
G, B) = (16,128,64). B
The same definitions apply to a and Bb, and a description thereof will be omitted.

Therefore, during the crossfade switching, the color data Xa of the color code ABa in the composite image X120.
(T) is the color data of the color code Aa (R, G, B) =
When the color data (R, G, B) = (64, 0, 16) of the color code Ba is gradually changed from (128, 32, 0), the R, G, and B of the color data Xa (t) are changed. The brightness levels are XaR (t), XaG (t), and XaB (t), respectively.
In the case of the expression (1), each of them is expressed by the expression (2) to the expression (4), and the specific value of the color data Xa (t) is as shown in FIG.

XaR (t) =-8t + 128 (Equation 2) XaG (t) =-4t + 32 (Equation 3) XaB (t) = 2t (Equation 4)

Similarly, color data Xb (t), Xc of color codes ABb, ABc, ABd in the composite image X120.
(T) and Xd (t) are also gradually changed. Then, the composite image X120 is changed from the original image A100 to the original image B.
It seems to switch gradually while overlapping to 100. In this way, different images can be displayed by crossfade switching by gradually changing the image components as time elapses t.

FIG. 4 shows original images A100 to B11.
Synthetic image X120 that changes to 0 over time t
It is a transition diagram showing the state of. In FIG. 4, 130 is the state at the crossfade start time (0th stage) of the composite image X120 shown in FIG. 1, 131 is the state at the second stage after the start of the crossfade, and 132 is the state after the start of the crossfade. The state of four stages, 133 is the state of the sixth stage after the start of the crossfade, and 134 is the state of the end point of the crossfade (the eighth stage). First,
Illustrations are omitted for the third, fifth, and seventh stages.

At the time of starting the crossfade (the 0th stage), as is clear from the equations 2 to 4 and FIGS. 2 and 3, the color data Xa (0) to Xd (0) are all original image A1.
Since the display image 130 is represented by only the color component of 00, the display image 130 looks like the original image A100 itself.

Similarly, in the second step after the start of the crossfade, the color data Xa (2) to Xd (2) are the original image A1.
00 R, G, and B luminance components of 75% and the original image B110
Since each of the R, G, and B luminance components of 25% is added, the state 131 of the composite image X120 looks like the original image B110 and the original image B110 overlap lightly.

At the fourth stage after the start of the crossfade, the color data Xa (4) to Xd (4) are R, R of the original image A100.
50% of each luminance component of G and B and R, G, of the original image B110
Since each luminance component of B is added by 50%, the state 132 of the composite image X120 is the original image A100 and the original image B1.
It looks like 10 overlaps.

At the sixth stage after the start of the crossfade, the color data Xa (6) to Xd (6) correspond to R, R of the original image A100.
25% of each luminance component of G and B and R, G, of the original image B110
Since 75% of each luminance component of B is added, the state 132 of the composite image X120 looks like the original image A100 is lightly overlapped with the original image B110.

At the end of the crossfade (8th step), all the color data Xa (8) to Xd (8) are the original image B1.
Since it is represented by only the 10 color components, the state 134 of the composite image X120 looks like the image B110 itself.

By thus changing the color data with the lapse of time t, the composite image X120 can be cross-fade switched. Also, the original image A100
When the crossfade is switched from the original image B110 to the original image B110, the image can be switched instantaneously by making a transition in one step. In this case, the color codes ABa, A
The color data of Bb, ABc, and ABd are converted from the color data of color codes Aa, Aa, Ab, and Ab to color code Ba,
The color data of Bb, Ba, Bb may be rewritten.

If the entire original image A100 has one color code (that is, a monochrome bitmap), cross-fading between the original image A100 and the original image B110 will result in the original image B110. Is displayed as a fade-in display. Therefore, if Aa = Ab (that is, a single color) is set as the color code at the start of the crossfade, the composite image X120 is used to change the original image B1 from the Aa single color.
A fade-in display to 10 can be made. Similar to the case of fading in, the fading out can be realized if it is considered that the entire original image B110 has one color code.

The resolutions of the two types of images do not necessarily have to be the same size. For example, the original image A1
When the resolution of the original image B110 is smaller than that of the original image B00 in the horizontal and vertical directions, the original image A100 and the original image B110 are included in the color code of the bitmap area where the two images do not overlap.
If each color data is set and the color code of the bitmap area in which the two images overlap is subjected to crossfade switching, image switching, etc. using the above composite image, 2
CLU is also applied to a part of the display image where the images overlap.
It is possible to display two images only by changing T.

FIG. 5 is a conceptual diagram showing a process of creating a composite image from two independent types of images by the color image display method as one embodiment of the present invention. In FIG. 5, the original image A100 has image information of 8 bits for each color of R, G, and B (24 bits in total), and the original image B11
0 has 8 bits of image information for each color of R, G, B (24 bits in total), and is 1 when displaying each original image.
Display is performed by using a combination of a bitmap corresponding to one color code per pixel and a CLUT for converting the color code into color data. Here, a case where the CLUT has a color code of 256 colors (8-bit color code) will be described as an example.

The display image of the original image A100 is CLUTA.
201 and a bitmap A202, and each pixel of the bitmap A202 is composed of 16 colors from color code 0 to color code 15. Similarly, the display image of the original image B110 is composed of a CLUT B211 and a bitmap B212, and each pixel of the bitmap B212 is composed of 16 colors from color code 0 to color code 15. Each CL
The UT uses only 16 of the 256 color codes.

The composite image X120 is displayed using the CLUTX 221 and the bitmap X222. CLUTX2
Reference numeral 21 is a combination of CLUTA 201 and CLUTB 211 by arithmetic processing according to the principle diagram shown in FIG.
202 and the bitmap B212 are combined by arithmetic processing.

When each of the above image information is created, the CLUT and the bitmap data of 16 colors are derived from the original image. As this method, for example, the color appearance distribution of the original image is analyzed to determine the frequency. 16 colors CLU with high colors as representative colors
Next, there is a method in which each pixel of the original image is replaced with the closest representative color in the CLUT to form a bitmap. In addition, in the original image such as computer graphics,
If the number of colors that appear is 16 or less, this derivation process is unnecessary.

Also, CLUTX 221 of 256 colors is created from two CLUTs of 16 colors. This is a CLUT.
CL the upper 4 bits of the 8 bits of the X221 color code
The color code of UTA201 is assigned and the lower 4 bits are C
It is created by assigning the color code of LUTB211. Similarly, each pixel of the bitmap X222 is a bitmap A2.
02 and the color code of the pixel of the bitmap B212 are converted into the color codes assigned to the upper 4 bits and the lower 4 bits, respectively.

By doing this, the bitmap X222
Each pixel inside is a color code of CLUTA201 and CL
It is possible to easily identify which color code of the UTB 211 is the color code synthesized.

FIGS. 6 and 7 are explanatory views for explaining the contents of the CLUT in FIG. 5, respectively. In the following description of FIGS. 6 and 7, color codes and color data are all represented by hexadecimal numbers.

In FIGS. 6 and 7, CLUTA 20
1 and CLUTB211 each have a color code of 16 colors (4 bits), and CLUTX221 is a bitmap A
This is a CLUT in which 202 and the bitmap B212 are combined according to the principle diagram shown in FIG. 1, and has a color code of 256 colors (8 bits).

Now, a method of switching images by changing the CLUT in this embodiment will be described with reference to FIGS. 6 and 7. Among the 8 bits of the color code of CLUTX 221, the upper 4 bits are assigned the color code of CLUTA 201, and the lower 4 bits are assigned the color code of CLUTB 211. For example, referring to FIGS. 6 and 7, CLUTX22
1 color code = 00 is CLUT 201 color code = 0
And the color code 0 of CLUTB211 are combined, and the color code of CLUTX221 = 10 is CLUTA2.
The color code of 01 = 1 and the color code of CLUTB211 are combined.

CLUTX2 synthesized by such a rule
If the actual color data is set for 21, the composite image X
Although the display of 120 changes, when displaying the original image A100, as shown in FIG. 6, the CLUTX 221 is displayed.
In each color code of, the upper 4 bits of the color code of 0 is the color data of the color code 0 of the CLUTA 201, and the upper 4 bits of 1 is the color data of the color code of 1 of the CLUTA 201. For the color code whose upper 4 bits are F, the color data of the color code F of the CLUTA 201 is set.

In this way, each pixel of the bitmap X222 of the composite image X120 has four color codes of two images.
Even if each bit is provided, the color data is determined only by the upper 4-bit color code regardless of the lower 4-bit color code. As a result, the bitmap X222 of the composite image X120 must display the original image A100 itself. become.

On the contrary, when the original image B110 is displayed, as shown in FIG. 7, among the color codes of the CLUTX 221, the color code whose lower 4 bits are 0 is CLUTB.
The color data of color code 0 of 211, the color code of lower 4 bits of which is 1, the color data of color code 1 of CLUTB 211 is,
If the color data of the color code F of the CLUTB 211 is set, the bitmap X222 of the composite image X120 will display the original image B110 itself as in the case of FIG.

The instantaneous image switching between the two images has been described above, but the crossfading can be easily performed by setting the CLUTX 221 by weighting the color data of the original two images according to the principle described with reference to FIG. ,Fade-in,
Fade out can be realized. In addition, since 4 bits of the color code are assigned to different images, it is easy to generate a composite image from the original image for each bit, and the effect is 4 bits if the original image is assigned in bit units. It is the same regardless of.

Further, for example, when performing switching display with two images having 10 color codes (that is, an image capable of displaying 10 colors), the color code numbers are arranged in a 10 × 10 array and If the dimension is assigned to two images, the two images can be switched in the same manner as in the present embodiment. In this case, it is not possible to generate a composite image from the original image bit by bit,
It is possible to determine which image dimension the color code number belongs to and generate a composite image.
Of the 6-color CLUT, 156 colors (= 256 colors-10 ×
It is also possible to use 10 colors) for images other than 2 images.

FIG. 8 is a block diagram showing a means for creating a composite image from two independent images by the color image display method as an embodiment of the present invention. In the figure, 300 is a VRAM (display memory) for storing the bitmap X shown in FIG.
Represents the color code of each pixel of the bitmap X stored in the VRAM 300 according to CLUTX 221 as R,
Color information conversion means for converting to G and B color data, which is 3
A display device 02 displays a composite image in accordance with the R, G, and B color data.

Further, A0 to A in CLUTA 201
15, B0 to B15 in CLUTB211 and CLU
X0 to X255 in the TX221 are shown in FIGS.
Represents the color code indicated by.

With reference to FIG. 8, a display method of crossfading switching between two images will be described by taking an example of crossfading switching from the original image A100 to the original image B110. Since the original image A100 is displayed at the start of display, C
Color code A0 of CLUTA201 in LUTX221
CL in which color data of color code A0 is set in the color code synthesized from, and color codes A1 to A15 are also used
The color data of the color codes A1 to A15 are also set in the color code of the UTX 221. At this time, which color code of CLUTA 221 is used by each color code of CLUTX 221 is defined based on FIGS. 6 and 7 at the time of creating the bitmap described in FIG. 5, and which color code of CLUTB 211 is also used. Similarly, it is defined when the bitmap is created.

During the crossfade, the CLUTX 221
Is the color code of CLUTA201 and CLU
Depending on which color code of the TB 211 is used for the combination, for example, as shown in FIG. 1, the color data of the CLUTX 221 is calculated by weighting the color data of each of the CLUTA 201 and the CLUTB 211 using the elapsed time t as a variable. To set.

Since the original image B110 is displayed at the end of display, the color data of the color code B0 is set in the color code synthesized from the color code B0 of the CLUTB 211 in the CLUTX 221, and the color codes B1 to B15 are used in the same manner. The color codes of the CLUTX 221 that are also color codes B1 to B
Set 15 color data.

The CLUTX 221 which is these color information is input to the color information converting means 301, and the 8-bit color code of each pixel of the bitmap X stored in the VRAM 300 is converted into the 8-bit R, G and B bits of the original image. Corresponding and converting, it outputs to the display device 302. In this way, the crossfades of two independent images can be displayed with one color code data.

FIGS. 9 and 10 are principle diagrams showing a process of creating a glow composite image from two independent original images by the color image display method as one embodiment of the present invention. 9 and 10 together form one principle diagram.

The glow described here is a method used when a part of a display image is emphasized, and is an image effect display system in which the surroundings of an object are illuminated so that back light is reflected. Also, in the following examples, 1 is used to represent the color code.
Hexadecimal notation is used.

In these figures, 400 is a pattern in which a red apple is on a blue background, 8 bits for each of R, G, and B.
It is the original image Pa represented by. An original image Pc 401 represents a gradation that changes from black to white from the outside toward the center of the apple. Reference numeral 402 is a CLUT Tc for displaying the original image Pc 401 in four colors.

Reference numeral 403 is a bitmap Mc in which the original image Pc 401 is replaced with a color code. 404 is
It is a histogram Hg showing the appearance frequency distribution of the color code of the bitmap Mc. 405 is the original image Pa 400
Is a CLUT Ga for displaying in 42 colors.

Reference numeral 406 is a bitmap Gm obtained by replacing the original image Pa 400 with a color code. 407 is
It is a CLUT Gc for displaying a glow image of the original image Pa 400 and the original image Pc 401 in 42 colors.

A method for creating a glow composite image will be described with reference to FIGS. 9 and 10. First, the original image Pc 401 is displayed with only four limited colors (that is, color-compressed). For example, in the three-dimensional color space, the original image Pc 401
, The darkest color (black) and the brightest color (white) are selected in the color distribution area, and the remaining two colors are in the color distribution area. , 4 colors as limited colors are determined by selecting colors (gray, dark) that are at even positions as much as possible (perform color compression).

Next, color data of four colors selected (black is color code 00, gray is color code 01, and dark is color code 0).
2 and white as the color code 03) are arranged in the order of luminance to form a CLU.
Let TTc 402 be the color of each pixel of the original image Pc 401 is C
The bit map Mc 403 is created by replacing the code with the closest color in the LUT Tc 402. For example, if a pixel in the original image Pc 401 has a color close to black, it is replaced with the color code 00. At this time, an error diffusion method or a dither method may be used to improve the image quality.

Here, the original image Pc 401 is color-compressed with 4 colors and the CLUT Tc 402 is described as 4 colors, but the number of colors to be used is free within the range of the CLUT limited number of colors. Also, the method of color compression is not limited.

Next, the original image Pa 400 is color-compressed with 42 colors. Upon color compression, it is determined how many kinds of colors are to be assigned to the area corresponding to each color code area of the bitmap Mc 403 at the same display position as the original image Pa 400. Regarding the method of determining the number of colors to be assigned, for example, a histogram Hg 404 of the number of pixels of the bitmap Mc 403 is created for each color code area, and the number of colors to be assigned to each color code area is determined by the ratio.

In FIGS. 9 and 10, CLUT Ga is
As shown in 405, in the area of the color code 00, 14 colors,
The color code 01 area is assigned 10 colors, the color code 02 area is assigned 6 colors, and the color code 03 area is assigned 12 colors.

The distribution state of the color data of the original image Pa 400 is obtained for each color code area, and the bit map Gm 406 is created by color compression with the number of colors shown in the CLUT Ga 405, as shown in FIG. For example, in the area of the color code 00, the representative color is 14
An original image Pa 4 corresponding to the area of the color code 00 is selected by selecting colors and using the color data of the color codes 00 to 0D of the CLUT Ga 405.
The color of each pixel of 00 is color code 00 of CLUT Ga405
Replace with the code of the closest color in the ~ 0D color data. At this time, an error diffusion method or a dither method may be used.

Finally, a CLUT for glow is created.
To create CLUTGc407 which is a CLUT for glow, for each color data of CLUT Ga405, C
It is obtained by adding the color data of LUT Tc402.

For example, color code 0 of CLUT Ga405
If it is in the range from 0 to 0D, add it with the color data (black) of color code 00 of CLUT Tc402, and use the CLU for glow.
Color data of color codes 00 to 0D of TGc407 is used.
The same applies to other ranges.

At this time, there may be an overflow of values that can be taken by the color data of the CLUT. However, at this time, a method of setting an upper limit on the data and a method of setting the upper limit at the time of real-time calculation during the display of the CLUT described later are described. There is a method of setting. The glow CLUT may be created during real-time calculation.

Furthermore, in order to create the CLUT Gc 407, for each color data of the CLUT Ga 405, C
Although the color data of the LUT Tc 402 is added, it may be subtracted to perform the glow of the effect of sinking the color, or addition and subtraction may be used in combination. The glow composite image is obtained by the CLUT Gc407, which is a CLUT for glow.

11 and 12 are principle diagrams showing a process of creating a composite image in which the number of colors of the display image changes stepwise by the color image display method as one embodiment of the present invention. FIG. 11 and FIG. 12 are combined to form one principle diagram.

In these figures, 500 is the original image P.
It is a CLUT Ta for displaying a 400 in four colors.
Reference numeral 501 is a bitmap Ma in which the original image Pa 400 is replaced with a color code.

Reference numeral 502 is a histogram Hd representing the appearance frequency distribution of the color code of the bitmap Ma. Fifty
3 is a CL for displaying the original image Pa 400 in 42 colors
This is UT Gah.

Reference numeral 504 is a bitmap Gma obtained by replacing the original image Pa 400 with a color code. 505 is
CLUT Ga for displaying the original image Pa 400 in four colors
l. A method of creating a composite image in which the number of colors of a display image is changed stepwise will be described with reference to FIGS. 11 and 12.

First, the original image Pa 400 is color-compressed with four colors. For example, in the three-dimensional color space, the original image Pa 400
The state of color distribution is calculated, and four colors (blue, bright red, red, dark blue) that are frequently used are selected within the color distribution area.

Next, color data of four colors selected (blue is 0
0, bright red 01, red 02, dark blue 03) CLUT
The color data of Ta500 is used, and the color of each pixel of the original image Pa400 is replaced with the color code of the closest color in the CLUT Ta500 to create a bitmap Ma501.

For example, if a pixel in the original image Pa 400 has a color close to red, the code 02 is replaced. At this time, an error diffusion method or a dither method may be used to improve the image quality. Here, the original image Pa 400 is compressed with four colors,
Although the CLUT Ta500 has been described as having four colors, the number of colors to be used is free within the range of the CLUT limited number of colors. Also, the method of color compression is not limited.

Next, the original image Pa 400 is color-compressed with 42 colors. In the color compression, it is determined how many kinds of colors are to be assigned to the area corresponding to each color code area of the bitmap Ma 501 at the same display position as the original image Pa 400. Regarding the method of determining the number of colors to be assigned, for example, a histogram Hd 502 of the number of pixels of the bitmap Ma 501 is created for each area of each color code, and the number of colors to be assigned to the area of each color code is determined by the ratio.

In FIG. 11 and FIG. 12, CLUT Ga
As shown in h 503, the color code 00 area has 14
The color / color code 01 area is assigned 10 colors, the color code 02 area is assigned 6 colors, and the color code 03 area is assigned 12 colors.

Then, this time, the state of the color distribution in the original image Pa 400 is obtained in the three-dimensional color space for each color code area, and the bit map Gma 504 is compressed by the number of colors shown in the CLUT Gah 503. create.

For example, in the case of the area of color code 00, 14 representative colors are selected centering on the blue color (background color), and C
The color data of the color code 00-0D of the LUT Gah 503 is used, and the color of each pixel of the original image Pa 400 corresponding to the area of the color code 00 is color code 00-0D of the CLUT Gah 503.
Replace with the code of the closest color in the color data of.
At this time, an error diffusion method or a dither method may be used to improve the image quality.

Finally, a CLUT for 4-color display is created. CLUT Gal 505 which is a CLUT for four-color display
Can be obtained by fitting the color data of the corresponding CLUT Ta500 into each color code of the CLUT Gah 503. For example, CLUT Gah 5
If it is in the range from 03 color code 00 to 0D, CLUT
All of the color data of Ta500 color code 00 (red) is replaced with the color data of color code 00-0D of CLUT Gal505 for color number reduction. The same applies to other ranges.

Next, in FIGS. 13 and 14, when the two figures are combined at the positions of the respective broken lines into one figure, two independent figures are displayed by the color image display method as one embodiment of the present invention. It is a principle diagram showing a process of creating a composite image for crossfade from images of various types.

In these figures, reference numeral 600 is an original image Pb in which a cherry picture is represented by R, G, and B for each 8 bits.
Is. Reference numeral 601 denotes the original image Pa 400 and the original image Pb.
This is a quantizing means for quantizing 600.

Reference numeral 602 denotes quantized data Qa obtained by quantizing the original image Pa 400. 603 is the original image Pb 600
Is quantized data Qb obtained by quantizing. A histogram Hq 604 represents an appearance frequency distribution of the values of the quantized data Qa 602 and the quantized data Qb 603.

Reference numeral 605 is a conversion means for converting the value of the quantized data into a color gradation. That is, if the quantized data is 0, the color gradation is 00, if the quantized data is 1, the color gradation is 55; if the quantized data is 2, the color gradation is AA; Is a means of converting into.

Reference numeral 606 denotes the original image Pa 400 and the original image Pb.
It is a merged CLUT Xab corresponding to 600. 607
Is a bitmap Xm in which the original image Pa 400 and the original image Pb 600 are simultaneously replaced by color codes.

Reference numeral 608 denotes the CL of the portion of the merged CLUT Xab 606 used to display the original image Pa 400.
It is UT Xa. 609 is a merged CLUT Xab 606
Of the part C used to display the original image Pb 600
LUT Xb.

With reference to FIGS. 13 and 14, a method of creating a cross-fading composite image will be described. First, preparations are made to select a representative color. As shown by the quantizing means 601, the original image Pa 400 and the original image Pb 600 are quantized to generate quantized data Qa 602 and quantized data Qb 603.

Here, as the quantization method, simply, R,
Original image Pa 400 and original image Pb of 8 bits each for G and B
Quantized data is obtained by shifting 600 to the right by 6 bits, but the quantization may be performed freely. The quantized data Qa 602 and the quantized data Qb 6
Histogram Hg 6
Create 04.

Next, the representative color is selected. In the histogram Hg 604, 256 colors are extracted as a merged CLUT Xab 606 in order of increasing color appearance frequency. At that time,
The conversion means 6 is associated with the color information conversion means 301 described later.
As indicated by 05, the quantized data is converted into color data. Here, the representative color is extracted according to the color appearance frequency, but the representative color may be extracted arbitrarily.

Finally, the bitmap Xm 607 is created. The color of each pixel of the original image Pa 400 and the original image Pb 600 is replaced with a color code that is as close as possible to each other in the color data of the merged CLUT Xab 606 to create a bitmap Xm 607. At this time, an error diffusion method or a dither method may be used to improve the image quality.

FIG. 15 is an explanatory diagram showing a method for reproducing an image using the color compressed image data created in FIGS. 9 to 14. In FIG. 15, reference numeral 700 is a calculation means for calculating the CLUT in real time.

A method of performing an image effect using the image data created in FIGS. 9 to 14 will be described with reference to FIG. First, the crossfade will be described.

In order to perform the crossfade, the bitmap Xm 607 created in FIGS. 13 and 14 is read into the VRAM 300 of FIG. 15 and the CLUT of FIG.
15 for Xa608 and CLUT Xb609.
The calculation shown in the calculation means 700 is performed and the value is transferred to the color information conversion means 301.

In the calculation means 700, Rout, Gout,
Bout is the value of the color data written in the color information conversion means 301. Ra, Ga, and Ba are values of color data in each code of CLUT Xa608. Rb, Gb, Bb are CL
It is a value of color data in each code of UT Xb609. k
(T) is a time function that gradually increases from 0 to 1 over time. Thus, the cross-faded image is reproduced on the display device 302.

Next, the glow will be described. To perform the glow, the bitmap G created in FIG. 9 and FIG.
m 406 is loaded into the VRAM 300 of FIG. 15 and CL
CLUT Ga405 is used instead of UTXa608, and CLUT Gc4 is used instead of CLUT Xb609.
07, the calculation shown in the calculation unit 700 is performed, and the value is transferred to the color information conversion unit 301.

At this time, if the values of Rout, Gout, and Bout overflow, the limiter is applied with the maximum value of the color data that the color information conversion means 301 can take. Ra, Ga, and Ba at this time are the values of the color data in each code of the CLUT Ga405. Rb, Gb, Bb are CLUT Gc40
It is the value of the color data in each code of 7. k (t) gradually increases from 0 to 1 over time, and then 1 to 0
Is a time function that gradually decreases to. In this way, the image on which the glow effect has been applied is reproduced on the display device 302.

Finally, the stepwise change in the number of colors will be described. In order to change the number of colors in steps, the bitmap Gma504 created in FIGS. 11 and 12 is changed to VR in FIG.
Read into AM300, use CLUT Gah 503 instead of CLUT Xa608, and use CLUT Xb609
CLUT Gal 505 is used instead of the above, and the calculation shown by the calculation means 700 is performed, and the value is converted into the color information conversion means 30.
Transfer to 1.

Ra, Ga, and Ba at this time are CLUT Ga.
It is the value of the color data in each code of h503. Rb, G
b and Bb are values of color data in each code of CLUT Gal505. k (t) is a time function that gradually increases from 0 to 1 or gradually decreases from 1 to 0 over time. In this way, an image in which the number of colors changes step by step is reproduced on the display device 302.

FIG. 16 is an explanatory diagram showing a method of performing high-quality glow display using a composite image created according to the principle shown in FIGS.

In FIG. 16, reference numeral 800 is a display image at the stage when the change in the number of colors is started or ended. 8
01 is a display image at the stage of entering or ending the glow. Reference numeral 802 is a display image during the glowing period.

First, image data for glow is created by the method shown in FIGS. Next, FIG. 11 and FIG.
Image data for changing the number of colors is created by the method shown in, but as CLUT Ta500, CLUT Ga405
All the colors used in (Fig. 9) are used. However, CLU
Since the same color is registered in multiple color codes in TGa405, the number of color codes in CLUT Ta500 is CLU.
Use less than the number of T Ga405 color codes.

The display image displayed by the combination of the CLUT Ga 405 and the bitmap Gm 406 and the CLU
The color code in the bitmap Ma 501 is selected so that the display images displayed by the combination of T Ta 500 and the bitmap Ma 501 are exactly the same. Below, Figure 1
1 and as described in FIG.

Finally, control of image data will be described. To adjust the image quality by gradually reducing the number of colors, the bitmap Gma 504 in FIG.
Read to 0, CL instead of CLUT Xa608
UT Gah 503 is used and CLUT Gal 505 is used instead of CLUT Xb609. Time function k
The calculation means 7 while gradually changing (t) from 0 to 1
00, and the value is converted into the color information conversion means 30.
Continuous transfer to 1.

When the time function k (t) reaches 1, the contents of the VRAM 300 are instantly switched to the bitmap Gm 406 to perform the glow, the CLUT Ga 405 is used instead of the CLUT Xa 608, and the CLUT Xb is used.
CLUT Gc 407 is used instead of 609.

The calculating means 70 while gradually changing the time function k (t) from 0 to 1 and again from 1 to 0
The calculation indicated by 0 is performed, and the value is converted into the color information conversion unit 301.
Continuous transfer to. At this time, if the values of Rout, Gout, and Bout have overflowed, the color information conversion unit 301
The limiter is applied with the maximum value of the color data that can be taken.

When the time function k (t) returns to 0, the VRAM 3 is used to adjust the image quality by gradually increasing the number of colors.
The contents of 00 are instantly switched to the bitmap Gma 504, and CLUT Gah is used instead of CLUT Xa 608.
503, CL instead of CLUTXb609
UT Gal 505 and time function k (t) from 1 to 0
The calculation shown in the calculation unit 700 is performed while gradually changing to, and the value is continuously transferred to the color information conversion unit 301.

By performing the above control, high quality and smooth glow display can be performed as shown in display images 801, 802 and 803 in FIG.

FIG. 17 is a schematic diagram of FIG.
It is explanatory drawing shown about the method of performing a high quality cross fade display using the synthetic image produced according to the principle shown in FIG.

In FIG. 17, 900 is the original image Pa 40.
It is a bitmap Xma for displaying a 0 symbol. This corresponds to the bitmap Gma504 (FIG. 12). 901
Is a CLUT Xal configured in the same color as the CLUT Xa 608 (FIG. 14). CLUT Gal 505 (Fig. 1
It corresponds to 2).

Reference numeral 902 is a CLUT Xah composed of a larger number of colors than the CLUT Xal 901. CLUT Gah
It corresponds to 503. Reference numeral 903 is a bitmap Xmb for displaying the design of the original image Pb 600. This corresponds to the bitmap Gma504.

Reference numeral 904 is a CLUT Xbl constructed in the same color as the CLUT Xb609. CLUT Gal 505
Equivalent to. Reference numeral 905 denotes a CLUT Xbh composed of a larger number of colors than the CLUT Xbl 901. CLUT Gah
It corresponds to 503.

Reference numeral 906 is a display image at the stage when the number of colors has started to change. Reference numeral 907 is a display image at the stage of entering the crossfade. Reference numeral 908 denotes a display image during the crossfade period. Reference numeral 909 is a display image at the stage when the cross fade ends. Reference numeral 910 is a display image at the stage when the change in the number of colors ends.

First, image data for crossfading is created by the method shown in FIGS. Next, FIG.
And image data for changing the number of colors is created by the method shown in FIG. 12, but in the case of the original image Pa 400, CLUT Ta is used.
As 500, all the colors used in CLUTXa 608 are used. However, since the same color is registered in a plurality of color codes in CLUT Xa608, CLUT Ta50
The number of color codes of 0 is smaller than that of CLUT Xa608.

Then, the display image displayed by the combination of the CLUT Xa 608 and the bitmap Xm 507, and the CLUT
The bit map M should be set so that the display images displayed by the combination of Ta500 and the bit map Ma501 become exactly the same.
a Select the color code in 501. This is as described in FIGS. 11 and 12 below.

Similarly, in the case of the original image Pb 600, CL
As UT Ta500, all colors used in CLUTXb 609 are used. Then, a display image displayed by combining the CLUT Xb609 and the bitmap Xm507,
The color code in the bitmap Ma 501 is selected so that the display images displayed by the combination of the CLUT Ta 500 and the bitmap Ma 501 are exactly the same. Less than,
This is as described in FIGS. 11 and 12.

Finally, the control of image data will be described. To adjust the image quality by gradually reducing the number of colors, the bitmap Gma 504 in FIG.
Read in, CLU as an alternative to CLUT Xa608
T Xah 902 is used and CLUT Xal 901 is used instead of CLUT Xb 609.

While the time function k (t) is gradually changed from 0 to 1, the calculation shown in the calculation means 700 is performed, and the value is continuously transferred to the color information conversion means 301. When the time function k (t) reaches 1, the contents of the VRAM 300 are changed to the bitmap Xm 507 for crossfading.
Switch to CLUT Xa608 and CLUTXb
Using 609, the calculation shown by the calculation unit 700 is performed while gradually changing the time function k (t) from 0 to 1, and the value is continuously transferred to the color information conversion unit 301.

When the time function k (t) reaches 1, the VRAM 3 is used to adjust the image quality by gradually increasing the number of colors.
The contents of 00 are instantly switched to the bitmap Xmb903, and CLUT Xbh is used instead of CLUT Xa608.
905, CL instead of CLUTXb609
UT Xbl 904 and time function k (t) from 1 to 0
The calculation shown in the calculation unit 700 is performed while gradually changing to, and the value is continuously transferred to the color information conversion unit 301.

By performing the above control, high quality and smooth crossfade display can be performed as shown in the display images 906 to 910 in FIG.

In the above embodiments, the CLU
It is clear that the present invention can be applied to any number of colors by limiting the number of colors of T data, and it has been explained as a composite image of two images, but it is not necessary to limit the number of images to two. , The number of colors assigned to one type of image is 1 or more,
Moreover, if the product of the number of colors assigned to each image is less than or equal to the number of colors in the CLUT, the effect of the present invention remains unchanged.

Furthermore, as explained in the principle diagram of FIG.
It is not said that the present invention is effective only for the entire display image, and for example, image effects such as crossfade, fade-in, fade-out, and glow can be performed even for a partial window of multi-window display.

In the above description, the display device using one CLUT has been described.
Even for a display device that uses a CLUT independently for G and B three colors, a composite image of a plurality of images according to the present invention is created for each R, G, B display plane, and each CLU for R, G, B is created.
If a composite CLUT according to the present invention is created and used for each T, the effect that a plurality of images can be displayed only by changing each RLUT for G, B, and B remains unchanged.

[0131]

As described above, according to the present invention, cross-fade switching, fade-in, fade-out, and fade-out can be performed with the number of images that can be stored in the VRAM or more without increasing the display memory capacity and the circuit scale. There is an advantage that image effects such as glow are possible.

[Brief description of drawings]

FIG. 1 is a principle diagram showing how a composite image is created from two independent types of images by a color image display method as an embodiment of the present invention.

2 is an original image A100 and an original image B1 in FIG.
Color codes Aa, Ab, B that compose 10 bitmaps
It is explanatory drawing which shows the specific value of the color data corresponding to a and Bb as an example.

3 is a color code AB in the composite image X120 of FIG.
It is explanatory drawing which shows the transition during the crossfade change of the color data Xa (t) corresponding to a.

FIG. 4 is a transition diagram showing a state of a composite image X120 that transitions from an original image A100 to an original image B110 with a lapse of time t.

FIG. 5 is a conceptual diagram showing a process of creating a composite image from two independent images by the color image display method as one embodiment of the present invention.

FIG. 6 is an explanatory diagram for explaining the contents of the CLUT in FIG.

FIG. 7 is an explanatory diagram for explaining the contents of the CLUT in FIG.

FIG. 8 is a block diagram showing means for creating a composite image from two independent types of images by the color image display method according to the embodiment of the present invention.

FIG. 9 is a principle diagram showing a first half of a process of creating a composite image from two independent types of images by a color image display method as one embodiment of the present invention.

FIG. 10 is a principle diagram showing the latter half of the process of creating the composite image shown in FIG. 9;

FIG. 11 is a principle diagram showing the first half of the process of creating a composite image in which the number of colors of the display image changes stepwise by the color image display method as one embodiment of the present invention.

FIG. 12 is a principle diagram showing the latter half of the synthetic image creating process shown in FIG. 11;

FIG. 13 is a principle diagram showing the upper half of the process of creating a composite image for crossfade from two independent images by the color image display method as one embodiment of the present invention.

FIG. 14 is a principle diagram showing the lower half of the process of creating a composite image for crossfade from two independent images by the color image display method according to the embodiment of the present invention.

FIG. 15 is an explanatory diagram showing a method of reproducing an image using the color compressed image data created in FIGS. 9 to 14;

FIG. 16 is an explanatory diagram showing a method of performing high-quality glow display using a composite image created according to the principle shown in FIGS. 9 to 12.

FIG. 17 is an explanatory diagram showing a method of performing high-quality crossfade display using a composite image created based on the principle shown in FIGS. 13, 14 and 11 and 12.

[Explanation of symbols]

Reference numeral 100 ... Original image A, 101 ... Monochromatic bitmap area of color code Aa, 102 ... Monochromatic bitmap area of color code Ab, 110 ... Original image B, 111 ... Monochromatic bitmap area of color code Ba, 112 ... Color code Bb Bit map area of 120, ... Synthetic image X, 121 ... Color code A
Monochromatic bitmap area of Ba, 122 ... Color code ABb
, Monochrome color bitmap area of color code ABc, 124 ... monochrome color bitmap area of color code ABd, 201 ... CLUTA, 202 ... bitmap A, 211 ... CLUTB, 212 ... bitmap B, 221 ... CLUTX, 222 ... Bitmap X, 3
00 ... VRAM, 301 ... Color information converting means, 302 ... Display device, 400 ... Original image Pa, 401 ... Original image Pc, 40
2 ... CLUT Tc, 403 ... Bitmap Mc, 404
… Histogram Hg, 405… CLUT Ga, 406…
Bit map Gm, 407 ... CLUTGc, 500 ... CL
UT Ta, 501 ... Bitmap Ma, 502 ... Histogram Hd, 503 ... CLUT Gah, 504 ... Bitmap Gma, 505 ... CLUT Gal, 600 ... Original image P
b, 601 ... Quantization means, 602 ... Quantized data Qa, 6
03 ... Quantized data Qb, 604 ... Histogram Hq, 6
05 ... conversion means for converting the value of the quantized data into color gradation,
606 ... Merged CLUT Xab, 607 ... Bitmap X
m, 608 ... CLUT Xa, 609 ... CLUT Xb,
700 ... Calculation means for performing CLUT calculation in real time, 800 ... Display image at the stage of starting or ending the change in the number of colors, 801 ... Display image at the stage of entering or ending the glow, 802 ... Glow Displayed image during the current period, 900 ... Bitmap Xma, 901 ... CLU
T Xal, 902 ... CLUT Xah, 903 ... Bitmap Xmb, 904 ... CLUT Xbl, 905 ... CLUT X
bh, 906 ... Display image at the stage when the number of colors starts to change, 9
07 ... Display image at the stage of entering the crossfade, 908
... Display image during crossfade period, 909 ...
Display image at the end of crossfade, 910 ... Display image at the end of color number change

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Koji Kawakami 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Incorporated Hitachi Image Information Systems Co., Ltd.

Claims (13)

[Claims] 1. An image using a bitmap that is a set of color codes corresponding to each pixel of the image and a color lookup table that associates color data with each color code that is an element of the bitmap. In the color image display method of displaying as a plurality of images, the bitmap and the color look-up table are prepared for a plurality of images, and a color code (hereinafter, referred to as a composite color code) corresponding to each pixel of the composite image is prepared. Created by synthesizing color codes corresponding to pixels at the same position as the pixel, each obtained from a plurality of the bitmaps,
A composite bitmap that is a set of the composite color codes is obtained, and color data (hereinafter referred to as composite color data) that is associated with each composite color code that is an element of the composite bitmap is provided in each of the plurality of prepared color data. Created on the basis of the color data associated with the color code combined to create the composite color code, each obtained from a color look-up table, and each composite color code that is an element of the composite bitmap is created. A color image display method, characterized in that a composite color lookup table that associates the composite color data with each other is obtained, and the composite image is displayed using the composite bitmap and the composite color lookup table. . 2. The color image display method according to claim 1, wherein among the prepared bitmaps and color lookup tables for a plurality of images, a bitmap and a color look used for displaying a first image. The up table is a first bitmap and a first color lookup table, and the bitmap and color lookup table used to display the second image are a second bitmap and a second color lookup table. In this case, the composite color data created based on the color data obtained from each of the plurality of color look-up tables is converted into the second color data from the color data obtained from the first color look-up table.
Color image display method, wherein the composite image to be displayed can be switched from the first image to the second image by instantaneously switching to the color data obtained from the color lookup table of . 3. The color image display method according to claim 1, wherein among the prepared bitmaps and color lookup tables for a plurality of images, a bitmap and a color look used for displaying a first image. The up table is a first bitmap and a first color lookup table, and the bitmap and color lookup table used to display the second image are a second bitmap and a second color lookup table. In this case, the composite color data created based on the color data respectively obtained from the plurality of color look-up tables is used as the color data and the second color obtained from the first color look-up table. Combine with the color data obtained from the look-up table at a predetermined ratio. A color image display method, wherein the synthesized image to be displayed can be an overlap image of the first image and the second image by using the generated data. 4. The color image display method according to claim 1, wherein among the prepared bitmaps and color look-up tables for a plurality of images, a bitmap and a color look used for displaying a first image. The up table is a first bitmap and a first color lookup table, and the bitmap and color lookup table used to display the second image are a second bitmap and a second color lookup table. In this case, the composite color data created based on the color data obtained from each of the plurality of color look-up tables is used as the color data and the second color obtained from the first color look-up table. A predetermined ratio with the color data obtained from the lookup table In addition to the generated data, the ratio is changed stepwise over time so that the displayed composite image can be switched from the first image to the second image by crossfade. A color image display method characterized by the following. 5. The color image display method according to claim 1, wherein the color look-up table (201) used for displaying the first image (100) is a first color look-up table, and a second color look-up table is used. A color lookup table (21 used to display the image (110).
1) as the second color lookup table, the composite color data created based on the color data obtained from each of the plurality of color lookup tables is converted into the first color lookup table ( 201)
The color data obtained from the second color lookup table (211) is added to the color data obtained from (211) at a predetermined ratio to obtain (221), and the ratio is changed stepwise with the passage of time. The image displayed by the composite bitmap (222) created based on the first color lookup table (201) and the second color lookup table (211) is converted into the first image (100). From the first image (1
00) and the second image (110) are gradually changed to a composite image, which is a color image display method. 6. The color image display method according to claim 1, wherein among the prepared bitmaps and color lookup tables for a plurality of images, a bitmap and a color look used to display a first image. The up table is a first bitmap and a first color lookup table, and the bitmap and color lookup table used to display the second image are a second bitmap and a second color lookup table. , The first image (400 in FIG. 11) and the second image (FIG. 1).
400 of No. 1) is the same as the original image, but the first color lookup table (50)
The number of colors is different between the first color data used in 3) and the second color data used in the second color lookup table (505 in FIG. 12), so that the first image and the second image are different. Are displayed in different color states, and are obtained from the first color lookup table (503) as composite color data created based on the color data obtained from each of the plurality of color lookup tables. By combining the first color data and the second color data obtained from the second color look-up table (505) at a predetermined ratio, and changing the ratio stepwise over time, From the first color data, through the mixed data of both color data, to the second color data,
Color image display characterized by obtaining composite color data that changes with time and gradually changing the displayed image from the first image to the second image whose color state is different from that of the first image. Method. 7. The color image display method according to any one of claims 1 to 6, wherein the number of color codes associated with color data in the color lookup table is a factorial of 2. At the same time, the number of composite color codes associated with the composite color data in the composite color lookup table is a factorial of 2. 8. The color image display method according to claim 2, 3 or 4, wherein a plurality of image data (40 in FIG.
0,600), a composite color lookup table (60 in FIG. 14) having color dimensions corresponding to the plurality of images.
6) is prepared, and a color code (hereinafter, referred to as a composite color code) corresponding to each pixel of the composite image is generated in the plurality of image data (4
00, 600), the color code closest to the color of the pixel at the same position is assigned to the composite color lookup table (60).
By selecting from the color codes of 6), a composite bitmap (607) that is a set of the composite color codes is obtained, and the composite image is displayed with the composite bitmap (607) and the composite color lookup table ( 606) and a color image display method. 9. The color image display method according to claim 5, wherein the second color lookup table (402) and the second bitmap (403) corresponding to the second image (401 in FIG. 9) are , The second image data (401) is created with c colors (where c is a natural number less than or equal to the limited number of colors in the color lookup table), and the first image data (400) is created with the second bitmap (4
03), it is divided into c areas, representative colors are obtained in the respective areas, a first color lookup table (405) composed of the representative colors is created, and the first color lookup table (405) is created. ) Is used to create a first bitmap (406) from the first image data (400), and as the composite bitmap used for image display,
A color image display method using the bitmap (406) of FIG. 10. The color image display method according to claim 6, wherein the second color lookup table (500) and the second bitmap (501) corresponding to the second image (400 in FIG. 11) are , The second image data (40
0) to c colors (where c is a natural number less than or equal to the limited number of colors in the color lookup table), and the first image data (400) is converted into the second bitmap (5).
01) is divided into c areas, representative colors are obtained in the respective areas, a first color lookup table (503) composed of the representative colors is created, and the first color lookup table (503) is created. ) Is used to create a first bitmap (504) from the first image data (400), and as the composite bitmap used for image display,
A color image display method using the bitmap (504) of FIG. 11. A color image display method characterized by performing cross-fade switching display using the color image display method according to claim 6 or 10 before and after the color image display method according to claim 4 or 8. . 12. The color image display method according to claim 6 or 10 before and after the color image display method according to claim 5 or 9 is used to convert the first image and the second image from the first image. A color image display method characterized by gradually changing to a sum of images. 13. The color image display method according to any one of claims 1 to 12, wherein the composite bitmap and the composite color lookup table used for displaying the composite image are composited in red. Red composite bitmap and red composite color look-up table used to display images, green composite bitmap and green composite color lookup table used to display green composite images, and blue composite A color image display method comprising: a blue color combination bitmap used for displaying an image; and a blue color combination color lookup table.