JPH0580016B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a computer image display device called computer graphics, and particularly to a technique for selecting colors of images.

[Conventional technology]

In computer graphics, a particular problem is how to color the screen. In particular, for example, when capturing a video signal from a VTR or video disc player into memory and making it a still image, and trying to draw the same picture as this still image on a computer, conventionally, colors that can be used for display are prepared. A color palette as a means is fixedly defined in advance, and coloring is performed using the defined colors, for example, 16 colors. In other words, most of the conventional color graphics devices are
The 16 colors used for display are often fixed.

In addition, it has been proposed that the color used to display this image can be selected from a large number of separately prepared colors, but in this case, the user can select the color from the still image displayed on the monitor receiver. I used to look at the original picture and set the colors to be used for displaying it.

[Problem that the invention seeks to solve]

For images created on a computer as shown above,
When trying to create colors that are almost the same as the original, it is difficult to achieve color reproduction by simply using 16 fixed, pre-prepared colors.

On the other hand, if the user selects and specifies 16 colors, an image with colors relatively close to the original image can be obtained by redefining the color palette several times. The disadvantage is that it takes a lot of time and effort to define it.

[Means for solving problems]

The present invention includes a digitizer 31 that converts analog video signal information into a digital signal, a memory 32 that stores an arbitrary screen worth of digital video signals from the digitizer 31, and a still image read out from the memory 32. The microcomputer 1 is equipped with a monitor receiver 6 for displaying images, and a microcomputer 1 to which the readout output of the memory 32 is transferred, and the microcomputer 1 creates a color image corresponding to the still image stored in the memory 32. A part of the screen of the digital video signal read out from the memory 32 displayed on the monitor receiver 6 is specified by a user's instruction. means 11 for displaying the part of the area, means for counting the appearance frequency of each color for a plurality of pixels included in the designated area, and the designated area being a plurality of areas. At this time, means for accumulating the appearance frequency of each color in each area, and N used for displaying a color image created by the microcomputer 1 based on the accumulated appearance frequency.
A means for specifying a color is provided.

[Effect]

When a part of the screen to be emphasized is specified by the means 11 for specifying a partial area of the screen, and multiple areas are specified by the means 11 for specifying the appearance frequency of each color information in this partial area. , are counted cumulatively, and N colors of the color palette are automatically defined in order from the one with the highest cumulative frequency.

〔Example〕

FIG. 2 is a diagram showing the overall outline of the device of this invention, and 1 is a microcomputer. This microcomputer 1 is equipped with a graphics function, and a color palette board can be attached via the I/O port or built-in, allowing you to select any of 4096 colors. There are 16 colors to choose from.

Reference numeral 2 denotes a video signal generation source such as a VTR or a video disk player, and these analog video signals are supplied to a video processing circuit 3. This video processing circuit 3 has a one-field memory 32 having a capacity to store one field of the digital video signal of a digitizer 31 that converts an input analog signal into a digital video signal, and is connected to the microcomputer 1 by a bus line. connected through. The video processing circuit 3 also includes a switch 33 that switches between the digital video signal from the digitizer 31 and the digital video signal created by this from the microcomputer 1 in response to a command generated by the keyboard operation of the microcomputer 1. , this switch 3
A D/A converter 34 is provided for converting the output of No. 3 back into an analog signal.

Further, 4 is a monitor receiver to which a video signal from the D/A converter 34 of the video processing circuit 3 is supplied.

Furthermore, 5 is a floppy disk drive device, which is also connected to the bus line of the microcomputer 1, and the floppy disk functions as a video RAM.

In this device, a reproduced signal from a video signal generation source 2, such as a VTR, is supplied to a video processing circuit 3, and a digitizer 31 converts a portion of one pixel (hereinafter referred to as pixel) into an 8-bit signal, which is then sent to a switch. The signal is supplied to the D/A converter 34 through 33, converted back into an analog signal, and supplied to the monitor receiver 4, and the original image of the reproduced color image is displayed on the monitor receiver 4.

The output signal of the digitizer 31 is also supplied to the input terminal of the 1-field memory 32, and according to the command from the microcomputer 1, the output signal of the reproduced color image displayed on the monitor receiver 4 is displayed at a predetermined point in time. The signal of one screen of
In this case, the video signal of one field is stored in memory 3.
Written to 2.

Then, the captured video signal of one field is converted into 16-color image data determined by a color palette created as described later based on instructions from the microcomputer 1, and transferred to the floppy disk 5. Stored on disk 5.

The image data is held in the memory 32 until it is rewritten by the next command from the microcomputer 1.

The image created by the microcomputer 1 is then displayed on the monitor receiver 4 via the switch 33 of the video processing circuit 3, with the image being switched with the original image processed by the digitizer 31.

Note that the image created by the microcomputer 1 may of course be always displayed on another monitor receiver.

Here, the original image on the screen of the monitor receiver 4 based on the digital video signal created by the digitizer 31 is divided into 8 pixels as shown in FIG.
It is composed of bit data and the horizontal direction of the screen is
The image consists of 448 pixels and 242 pixels in the vertical direction. On the other hand, the image created by the microcomputer 1 has 4 bits per pixel, 320 pixels in the horizontal direction, and 200 pixels in the vertical direction, as shown in Figure 4.
This becomes a pixel image, which is rough compared to the original image produced by the digitizer 31.

In this case, as mentioned above, the microcomputer 1 is equipped with a function that allows you to select and use 16 colors of your choice from 4096 colors, which allows you to select colors according to the original image. It is possible to express the reproduction of. In addition, this invention automatically sets the definition of a color palette consisting of 16 colors used to create a color image so that delicate colors can be reproduced, focusing on the colors of the parts of the original image that are particularly important. It has been taken into consideration that it can be done.

That is, FIG. 1 is a diagram for explaining the method of defining this color palette, and FIG. 7 is a flowchart within the microcomputer 1 for defining this color palette.
How to define this color palette will be explained below with reference to FIGS. 1 and 7 as well as FIGS. 5 and 6.

As shown in FIG. 7, when this color palette definition program is started, the original image converted into a digital signal by the digitizer 31 is converted back to an analog signal and displayed on the screen of the monitor receiver 4. As mentioned above, this is a finer image with a larger number of pixels than the image produced by the computer, as shown in FIG. 3 (step [101]).

Next, a cursor 11 is displayed on the original image on the monitor receiver 4 as shown in FIGS. 1A, B, and C (step [102]). Cursor 1 on this image
The position of 1 can be specified at any location by keyboard operation on the microcomputer 1. This is actually equivalent to specifying a plurality of addresses in the field memory 32 within the area surrounded by the cursor on the screen.

Therefore, the cursor 11 is brought to a position where the user wants to focus on color image creation by operating the keyboard. This is done in steps [103] and [104].
That is, in step [103] it is determined whether there is a designation to move the cursor 11, and if the desired position is different from the current position of the cursor 11, the display coordinates of the cursor 11 are changed in step [104]. , if the position of the cursor 11 is not the desired position, the process advances to the next step [105].

In this step [105], the cursor 1
The color data of each pixel of a plurality of pixels, for example 400 pixels, included in the area surrounded by 1 is stored. In this case, this color data is represented by three primary color data R, G, B of red, green and blue, and the fifth
As shown in the figure, 8 bits of data per pixel
For example, red data R is 3-bit data D ₁ -D ₃ , green data G is 3 _- bit data D ₄ -D ₆ , and _blue data B is 2-bit data.
They are expressed as D ₇ and D ₈ .

When this 400-pixel color data is written into the memory, the number of pixels in which the same color data appears is calculated (step [106]). In other words, the appearance frequency of each color is calculated. FIG. 6 diagrammatically shows the appearance frequency of each color information.

Then, this appearance frequency is cumulatively added to the appearance frequency of these colors up to that point (step [107]),
The 16 desired display colors are selected in descending order of the cumulative number of colors (step [108]). In this case, the initial value of the appearance frequency is 0, and each time the cursor 11 is moved and the specified area is changed, the appearance frequency is sequentially accumulated.

You can accumulate all 256 colors here, or you can accumulate the 16 colors you defined previously and the 16 colors you defined next.
It is also possible to calculate the frequency of appearance for a total of 32 colors (less than 32 if they overlap), and select 16 colors from the ones with the most occurrences.

If you think that it is still not possible to obtain a color image close to the original with the selected colors,
The user further operates the keyboard to move the cursor 11 to a desired position. Then, in step [109], it is detected that movement of the cursor 11 is specified, the display coordinates of the cursor 11 are changed again, and the cursor 11 is moved to the specified position.
For example, the cursor 11 is moved from the hair position in FIG. 1A to the cheek area of the human face as shown in FIG. 1B. Then, the steps from step [102] to step [107] described above are executed, the cumulative number for each color is calculated again, and the 16 colors are reselected in descending order of the cumulative number.

In the case of Figure 1 A, B, and C, 16 colors were first selected based on hair color, then reselected based on skin color, and then 16 additional colors were selected by incorporating eye color. This is if it is fixed.

Note that the step "Cursor movement specified?", which is similar to step [109], is changed to step [107].
and [108], instead of selecting 16 colors at each position of the cursor 11, the frequency of each color is determined first based on information from multiple areas that you want to focus on, and from this point the frequency of each color is determined at once. There are now 16 colors to choose from.

In this way, once 16 colors have been selected, centering on the colors of the areas of emphasis, the next step is to select the 16 colors (8
256 (8 bits) → 4096 (12 bits) from the 4096 colors (12 bits data) on the color palette board prepared in advance (bit data)
A corresponding one is selected according to the conversion table, and a color palette is defined thereby (step [110]).

In other words, in the above steps, 16 colors are first selected from 256 colors represented by 8 bits, and then
The 16 colors are selected in correspondence with the closest color among the 4096 colors expressed in 12 bits, and these 16 colors are defined as a color palette. These 16 defined colors are stored on the floppy disk.

Once the color palette is defined in this way, the process moves to step [111] for creating a computer image.

In this step [111], first, the correspondence between the colors of the image in the memory 32 and the selected 16 colors is calculated. When the selection of colors for all dots of the image in the memory 32 is completed, a command is executed to transfer the image in the memory 32 to the computer 1, and each pixel of the image to be displayed by the computer 1 is converted according to the conversion table. color is assigned as one of the 16 colors with 4 bits,
This 4-bit data is written to the floppy disk.

Then, the switch 33 is switched by operating the keyboard of the computer 1, and the color image produced by the computer 1 is displayed on the monitor receiver 4 as shown in FIG. 1D (step [112]).

Of course, at this time, depending on the conversion table, 4
The bit color selection data is converted to 12-bit color data, and each dot is colored. This projected computer image is then compared with the original image by switching the switch 33 by operating the keyboard of the computer 1, and if the selected color is not satisfactory, the color palette is redefined. That is, steps [101] to [110] are repeated, and the computer image is displayed on the monitor receiver 4 in steps [111] and [112]. Once the user has selected a color that satisfies him, the flow of defining the color palette ends.

〔Effect of the invention〕

As described above, according to the present invention, when obtaining an image with colors similar to the original image, it is possible to define a color palette centering on the colors of the parts of the original image that are desired to be emphasized. More faithful computer images can be easily obtained.

Furthermore, the user does not have to select the color palette one by one, but only by specifying the part of the image to be emphasized with a cursor, so there is an advantage that the color palette can be defined very easily.

[Brief explanation of the drawing]

FIG. 1 is a diagram for explaining the outline of the main parts of this invention, FIG. 2 is a diagram showing the outline configuration of the apparatus of this invention, FIGS. 3 and 4 are diagrams showing the configuration of a color image, FIG. 5 is a diagram for explaining color information of one pixel, FIG. 6 is a diagram used for explaining color selection, and FIG. 7 is a diagram showing an example of a flowchart for defining a color palette according to the present invention. 1 is a microcomputer, 31 is a digitizer, 32 is one field memory, and 4 is a monitor receiver.

Claims (1)

[Scope of Claims] 1. A digitizer that converts analog video signal information into a digital signal, a memory that stores one arbitrary screen worth of digital video signals from this digitizer, and a still image that is read out from this memory. The microcomputer has a monitor receiver to which the readout output of the memory is transferred, and the microcomputer creates a color image corresponding to the still image stored in the memory, and monitors the created image. A means for specifying a part of the screen of the digital video signal read from the memory and displayed on the monitor receiver according to a user's instruction; display means for displaying an area; means for calculating the appearance frequency of each color for a plurality of pixels included in the specified area; and when the specified area is a plurality of areas, each color in each area; A computer image display device comprising: means for accumulating the frequency of appearance of , and means for specifying N colors to be used for displaying a color image created by the microcomputer based on the accumulated frequency of appearance.