JPH05307379A - Display control device - Google Patents

Abstract

PURPOSE:To save the capacity of a video memory in a color data display control processing and to coexist, to display and to control multicolor and full color pictures. CONSTITUTION:A video memory 1 stores color data for a display purpose. Color data equivalent to one picture element read from the memory 1 are successively sent to a data selector 2 and at the data selector 2, a bit selection process is executed against the color data equivalent to one picture element. That is to say, the data selector 2 makes a selection against the color data whether to output the data with an 8 bit luminance data (Y component), 4 bit color difference data (B-Y component) and 4 bit color difference data (R-Y component) constitution or to output the data with a 12, 2, 2 bit constitution, respectively under the control of a switch section 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a color facsimile,
The present invention relates to a display control device which is used for an image database, a color printer, etc. and controls display on a display device.

[0002]

2. Description of the Related Art Generally, as color data, multi-color data for the purpose of displaying color for identifying text and graphics, and full color data for displaying a natural image. In the case of multi-color data, it is sufficient to have an information amount of 4 to 8 bits per pixel, but in the case of full color data, it is 2 per pixel.
A 4-bit information amount is often used. in this way,
In the case of performing display control processing for color data, particularly in the case of full color data, the amount of information is large, and in the past, a large amount of memory was required.

[0003]

Therefore, in the display control processing of color data, saving the video memory is one of the problems for those skilled in the art. Also, in the past,
It was difficult to control the display by mixing a multi-color image and a full-color image.

According to the present invention, it is possible to save the video memory in the display control processing of the color data, and it is possible to control the display by mixing the multicolor image and the full color image. The purpose is to provide a device.

[0005]

In order to achieve the above object, according to the invention of claim 1, bit selection processing is performed on the color data for one pixel read from the storage means by mode switching by the switching means. Is performed to control the display of color data of plural types.

According to the second aspect of the invention, the attribute information is assigned to the color data stored in the storage means, and the switching means switches the bit selection mode based on the attribute information. Therefore, color data of different types can be mixed in one video memory.

According to the third aspect of the invention, the storage means stores the luminance / color difference system color data, and the bit selection means changes the bit configuration of the luminance component and the color difference component in the color data for one pixel. This is possible, and when the number of bits of the luminance component is expanded, the number of bits of the color difference component is reduced by the expanded number of bits.

Further, according to the present invention, the color data read from the storage means is subjected to the bit configuration and resolution selection processing for the color difference component by mode switching by the switching means.
Only one storage means, that is, a video memory is required to perform color data display control that emphasizes resolution and display control of color data that emphasizes color difference gradation.

According to the invention of claim 5, attribute information is assigned to the luminance / chrominance color data stored in the storage means, and the switching means sets the bit configuration for the color difference components based on the attribute information. Since resolution selection processing is performed, color data that places importance on resolution and color data that places importance on color difference gradation can be mixed in one video memory.

According to the sixth aspect of the present invention, when attribute information is assigned to the luminance / color-difference color data stored in the storage device, a plurality of pixels are assigned depending on the coarseness of resolution of the color data. One piece of attribute information can be assigned.

According to the invention described in claim 7, attribute information is assigned to the color data stored in the storage means corresponding to the color data, and the conversion matrix corresponding to the attribute information is stored in the coefficient storage means. Is stored, and when the color data for one pixel is read out, a conversion matrix corresponding to the attribute information of the color data is output from the coefficient storage means and joins the calculation means.
This conversion matrix is applied to the color data to convert the color space.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram of a first embodiment of a display control device according to the present invention. This display control device is a color display device.
A video memory (VRAM) 1 for storing data,
A data selector 2 which performs bit selection processing on the color data for one pixel read from the video memory 1.
And a switching unit 3 for switching the mode to the data selector 2, and first, second and third D / A for performing D / A conversion on the data respectively output from the data selector 2. It has A converters 4, 5, and 6.

In this example, the video memory 1 has a total of 16 bits of data D0 as one pixel of color data.
D15, more specifically, 8-bit luminance data (Y component), 4-bit color difference data (BY component), and 4-bit color difference data (RY component) are stored. Or
It is assumed that 12-bit luminance data (Y component), 2-bit color difference data (BY component), and 2-bit color difference data (RY component) are stored. This color
The luminance data (Y component) and the color difference data (B-
Y component), color difference data (RY component) 8,
In the case of 4- and 4-bit data, D8 to D15 are luminance data (Y component), and D4 to D7 are color difference data (BY).
Components), D0 to D3 are assigned as color difference data (RY components). On the other hand, when the luminance data (Y component), the color difference data (BY component), and the color difference data (RY component) are respectively made of 12, 2 and 2 bits, D4 is used.
To D15 are luminance data (Y component), D2 to D3 are color difference data (BY component), and D0 to D1 are color difference data (RY).
It is designed to be assigned as a component).

The data selector 2 is for one pixel read from the video memory 1 (that is, 16 bits).
Under the control of the switching unit 3,
The luminance data (Y component), the color difference data (BY component), and the color difference data (RY component) of 8 bits, 4 bits each are output, or 12 bits each are output. It is designed to select whether to output in a 2-bit or 2-bit configuration.

FIG. 2 is a diagram showing an example of the structure of the data selector 2. In this example, the data selector 2 is composed of three multiplexers 11, 12, and 13. The multiplexer 11 is provided to expand the luminance data (Y component) from 8 bits to 12 bits by 4 bits, and the data D8 of the 16-bit color data D0 to D15 is supplied to all four ports of one side. And the 4-bit data D4 to D7 are input to the other four ports. Further, the multiplexer 12 is designed so that 4-bit data D4 to D7 are input to four ports on one side and data D2 to D3 are input to the other four ports (D3 is input to the upper 1 port). , D2 is input to the lower 3 ports). Further, the multiplexer 13 inputs the data D0 to D3 into one of the four ports,
The data D0 to D1 are input to the other four ports (D1 is input to the upper 1 port and D0 is input to the lower 3 ports). Also, each multiplexer 1
The switching signal SEL from the switching unit 3 is added to 1, 12, and 13, so that the input of four ports on one side is selected and output, or the input of the other four ports is selected and output. Whether to do it is controlled.

The first, second, and third D / A converters 4, 5, and 6 have D / A of 12, 4, and 4 bits, respectively.
An A converter is used. The switching unit 3 is composed of, for example, a flip-flop or a manual switch.

Next, the operation of the display control device of the first embodiment having such a configuration will be described. When displaying color data on a display device (not shown), the display control device sequentially reads the color data of each pixel stored in the video memory 1 pixel by pixel. At this time, as shown in FIG. 3A, each color data in the video memory 1 includes 8-bit luminance data (Y component), 4-bit color difference data (BY component), 4-bit color difference data (RY
Component), the switching unit 3,
For example, the states of flip-flops and manual switches are set beforehand to those corresponding to this bit configuration. In this case, when the color data for one pixel read from the video memory 1 is applied to the data selector 2, the data selector 2 inputs the inputs of the four ports of one of the multiplexers 11, 12, and 13 from the switching unit 3. The signal is selected by the switching signal SEL and given to the first, second, and third D / A converters 4, 5, and 6, respectively. That is, the D / A converter 4,
To 5 and 6, 8-bit luminance data (Y component), 4-bit color difference data (BY component), and 4-bit color difference data (RY component) are added. Each is converted into an analog signal and sent to a display device (not shown). As a result, 8-bit luminance gradation and 4-bit color difference gradation can be displayed on the screen of the display device.

On the other hand, as shown in FIG. 3 (b), the color data in the video memory 1 includes 12-bit luminance data (Y component) and 2-bit color difference data (BY component). , 2
When the bit color difference data (RY component) has a bit configuration, the state of the switching unit 3, for example, a flip-flop or a manual switch is set to a state corresponding to this bit configuration (that is, Set in the opposite state) in advance. In this case, when the color data for one pixel read from the video memory 1 is added to the data selector 2,
In the data selector 2, each multiplexer 11, 12, 1
The inputs of the other four ports of the switch 3 are selected by the switch signal SEL from the switch 3, and are added to the first, second, and third D / A converters 4, 5, and 6, respectively. That is, D /
The A converters 4, 5 and 6 have 8-bit luminance data (Y component), 4-bit color difference data (BY component), 4-bit color difference data (RY component). Are added, and these are converted into analog signals and sent to a display device (not shown). As a result, 12-bit luminance gradation and 2-bit color difference gradation can be displayed on the screen of the display device.

As described above, in the first embodiment, even when a plurality of types of display data corresponding to a plurality of types of display data are displayed, a plurality of video memories are provided for each of the plurality of types of display data. It does not need to be provided, and only one video memory is required. Further, a predetermined bit length (16 bits) for one pixel of the video memory 1 can be shared by a plurality of types of display data. As a result, the amount of memory can be significantly reduced compared to the conventional case.

Further, in the first embodiment, the luminance data is
This can be easily extended from 8 bits to 12 bits for the data (Y component). That is, in this case, as the plurality of types of display data, it is possible to set two types of the luminance data (Y component) having 8 bits and the luminance data (Y component) having 12 bits. it can. However,
When the luminance data (Y component) is expanded to 12 bits, the color difference data (BY component) and (RY component) are reduced to 2 bits, respectively, and the amount of information is reduced. .. However, in general, the human eye is sensitive to brightness but insensitive to color. Therefore, even if the amount of color information is reduced, the viewer of the display screen is not affected by color deterioration and the like, while the amount of luminance information is increased, so that the quality of the color image can be increased.

In Japanese Patent Laid-Open No. 62-28794, each bit length when the color signal to be displayed is divided into a red luminance control signal R, a green control signal G, and a blue control signal B is variable. As a result, an apparatus capable of increasing the allocated bit length for the color component used is disclosed. However, as described above, even if the information amount of the color component is expanded, the effect on the human eye is affected. Is not much. In addition, some data have conventionally had luminance data of 8 bits or more, such as X-ray photographs and photographs from artificial satellites, but these required rounding processing. On the other hand, in the first embodiment, it is possible to easily realize a display having a large luminance range without requiring any complicated processing such as rounding processing.

By the way, in the example of FIG. 1, the switching unit 3 is composed of a flip-flop or a manual switch.
Such a configuration is preferable when the switching frequency of the data selector 2 is not so high. That is, for example, the type of color data stored in the entire video memory 1 is the same, which is suitable when the type of color data is switched in screen units. However, when different types of color data are mixed in one screen, that is, when different types of color data are mixed and stored in the video memory 1, the switching timing may be difficult. .. Therefore, in this case, as shown in FIG. 4, instead of a flip-flop or a manual switch,
A flag FLG for switching control of the data selector 2 is provided as attribute information in the data for one pixel of the video memory 1, and the data selector 2 is switched depending on the value "1" or "0" of this flag FLG. May be. That is, the luminance data (Y component) of one pixel of color data read from the video memory 1 and the color difference data (B-
Y component), color difference data (RY component) is 8,
In the case of 4 and 4 bits, the flag FL is associated with this.
G is set to "0", and in the case of 12, 2, and 2 bits, the flag FLG is set to "1" correspondingly. As a result, even when different types of data are mixedly stored in the video memory 1, the data selector 2 is automatically switched according to the type of data.
It is possible to mix, for example, a portion that emphasizes luminance and a portion that emphasizes color difference information on one screen.

FIG. 5 is a block diagram of a second embodiment of the display control device according to the present invention. In FIG. 4, the same parts as those in FIG. 1 are designated by the same reference numerals. This display control device includes a video memory (VRAM) 1 in which color data for display is stored, and luminance data (Y component) of color data for one pixel read from the video memory 1.
Of the color difference data (BY component) and (RY) of the color data for one pixel.
The first and second selector / latch units 22 and 23 for performing bit selection and latch processing on the
And a switching unit 24 that performs mode switching for the second selector / latch units 22 and 23, the latch unit 21, and the first
And the first, second, and third D / A conversion units 25, 26, and 27 that perform D / A conversion on the data output from the selector / latch unit 22 and the second selector / latch unit 23, respectively. have.

In this example, the video memory 1 has a total of 16 bits of data D0 as color data for one pixel.
D15, more specifically, 8-bit luminance data (Y component), 4-bit color difference data (BY component), and 4-bit color difference data (RY component) are stored. Or
8-bit luminance data (Y component), 8-bit color difference data
Data (B-Y component or R-Y component) is stored. When the luminance data (Y component), the color difference data (BY component), and the color difference data (RY component) of the color data are set to 8, 4 and 4 bits, respectively. , D8 to D15 are luminance data (Y component), D
4 to D7 are assigned as color difference data (BY component), and D0 to D3 are assigned as color difference data (BY component). on the other hand,
When the luminance data (Y component) and the color difference data (BY component or RY component) are 8 and 8 bits respectively, D8 to D15 are luminance data (Y component), D0 to D7
Is assigned as color difference data (BY component or RY component).

The latch section 21 is composed of, for example, an 8-bit latch corresponding to 8-bit luminance data (Y component). The first and second selector / latch sections 22 and 23 are each composed of a 4-bit selector / 8-bit latch. FIG. 6 is a diagram showing a configuration example of the first selector / latch unit 22. As the first selector / latch section, 4-bit data D4 to D7 are used.
Latch circuit 31 for latching the
Input to all one port, 4-bit data D0 to D3
Input to the other four ports and select each of these inputs by the switching signal SEL from the switching unit 24 to output, a latch circuit 33 that latches the output from the multiplexer 32, and the switching unit 24. the switching signal SEL from either a clock for the latch circuits 31 and 33 to the clock CLK ₀ of the fundamental frequency f _0, a frequency f _0/2 1/2 of the fundamental frequency f ₀ clock CLK ₁
It has a multiplexer 34 for selecting whether or not to.

FIG. 7 shows the second selector / latch unit 2
It is a figure which shows the structural example of 3. The second selector / latch unit 23 has a latch circuit 41 for latching 4-bit data D0 to D3 and data D3 input to all four ports, and data D4 to D7 to the other four ports. A multiplexer 42 which inputs, selects each of these inputs by a switching signal SEL from the switching unit 24, and outputs the selected signals.
When a latch circuit 43 for latching an output from the multiplexer 42, the fundamental frequency f ₀ of the clock for the latch circuits 41 and 43 by the switching signal SEL from the switching section 24
If to the clock CLK _0, and a multiplexer 34 for selecting either the clock CLK ₂ 1/2 frequency f _0/2 of the fundamental frequency f _0.

The clock CLK ₁ used in the _first selector / latch section 23 and the clock CLK ₂ used in the second selector / latch section 23 are as shown in FIG.
As shown in (b), the phase is shifted by a half cycle,
Therefore, the first and second selector / latch sections 22 and 23
, When operating at frequency f _0/2 of the clock CLK _1, CLK _2, and is configured to output data alternately.

Next, the operation of the display control device of the second embodiment having such a configuration will be described. When displaying color data on the display device, the display control device sequentially reads the color data of each pixel stored in the video memory 1 pixel by pixel, as in the first embodiment. FIG. 9A shows addresses # 1 and # of the video memory 1.
It is a figure which shows the 1st example of the color data for 1 pixel each memorize | stored in 2, ..., #n. As in the first example, color data at addresses # 1 to #n are all of the same format, and 8-bit luminance data (Y component),
In the case of the bit configuration of 4-bit color difference data (BY component) and 4-bit color difference data (RY component), the clocks CLK ₀ are output from the first and second selector / latch units 22. The state of the switching unit 24, for example, the flip-flop is set so that 4-bit color difference data (BY component) and 4-bit color difference data (RY component) are output in synchronization with each other. At this time, in the first selector / latch section 22, the input of one of the four ports of the multiplexer 32 is selected and added to the latch circuit 33. As a result, in synchronization with the clock CLK ₀ , the first selector /
Inputs D4 to D7 from the latch circuit 31 of the latch unit 22.
The data D4 'to D7' corresponding to are output, and
From the latch circuit 33, data D0 ′ to D3 ′ corresponding to the input (all D4) are output. On the other hand, in the second selector / latch section 23, the input of one of the four ports of the multiplexer 42 is selected and added to the latch circuit 43. As a result, the second clock is synchronized with the clock CLK ₀ .
The data D4 "to D7" corresponding to the inputs (all D3) are output from the latch circuit 43 of the selector / latch unit 23, and the data D0 "to D3" corresponding to the inputs D0 to D3 are output from the latch circuit 41. Is output. Also,
Data corresponding to the inputs D8 to D15 is output from the latch unit 21. In this way, the latch unit 21, the first selector / latch unit 22, and the second selector / latch unit 2
Each data output from the 3rd is the first, second and third D /
The signals are added to the A converters 25, 26 and 27, converted into analog signals and sent to the display device. That is, in the display device, 8-bit luminance data (Y component) D8 to D15 from the first D / A conversion unit 25 and 8-bit data D0 ′ to D7 from the second D / A conversion unit 26. 'And 8-bit data D0 "to D7" from the third D / A converter 27 are sent. However, in this case, of the 8-bit data D0 'to D7' from the second D / A converter 26, only 4-bit D4 'to D7' correspond to 4-bit color difference data (BY component). The remaining 4 bits D0 ′ to D3 ′ are ignored as dummy bits in, for example, a display device. Similarly, the third D /
8-bit data D0 "to D7" from the A converter 27
Among them, only 4-bit data D0 ″ to D3 ″ corresponds to 4-bit color difference data (RY component), and the remaining 4-bit D4 ″ to D7 ″ are dummy bits in the display device. It will be ignored. As a result, from the display control device, as shown in FIG.
In synchronization with the clock CLK ₀ , data from the addresses # 1 to #n of the video memory 1, that is, 8-bit luminance data (Y component), 4-bit color difference data (BY).
Component) and 4-bit color difference data (RY component) are sequentially sent to the display device, and 8-bit luminance gradation and 4-bit color (BY, RY) are displayed on the display screen. Color display with gradation is possible.

On the other hand, FIG. 10A is a diagram showing a second example of color data for one pixel stored at addresses # 1, # 2, ..., #n of the video memory 1. is there.
In the second example, the color data at addresses # 1 to #n are of different formats, and are composed of 8-bit luminance data (Y component) and 8-bit color difference data (BY component). The first type data and the second type data composed of 8-bit luminance data (Y component) and 8-bit color difference data (RY component) are alternately stored. In this case, the clock C from the first selector / latch unit 22
4-bit color difference data (BY component) is output in synchronization with LK ₁ , and the second selector / latch unit 23 is also provided.
The state of the switching unit 24, for example, the flip-flop is set so that 8-bit color difference data (RY component) is output in synchronization with the clock CLK ₂ . At this time, in the first selector / latch unit 22, the multiplexer 32
Of the other four ports of the latch circuit 3 are selected.
Join 3. As a result, the data D4 ′ to D4 corresponding to the inputs D4 to D7 from the latch circuit 31 of the first selector / latch unit 22 are synchronized with the clock CLK _1.
7'is output, and D is input from the latch circuit 33.
Data D0 ′ to D3 ′ corresponding to 0 to D3 are output. On the other hand, in the second selector / latch unit 23 in synchronization with the clock CLK ₂ , the other 4 of the multiplexer 42 is connected.
The input of one port is selected and added to the latch circuit 43. As a result, in synchronization with the clock CLK ₀ , the latch circuit 43 of the second selector / latch unit 23 outputs data D4 ″ to D7 ″ corresponding to the inputs D4 to D7 in synchronization with the clock CLK ₀ , and From the latch circuit 41, data D0 ″ to D0 corresponding to inputs D0 to D3
3 "is output. Also, the input D8 is input from the latch unit 21.
Data corresponding to D15 to D15 are output. In this way, the respective data output from the latch unit 21, the first selector / latch unit 22, and the second selector / latch unit 23 are the first, second, and third D / A conversion units 25, 26. , 27
To the display device after being converted into an analog signal. That is, in the display device, 8-bit luminance data (Y component) D8 to D15 from the first D / A conversion unit 25 and 8-bit data D0 ′ to D7 from the second D / A conversion unit 26. 'And 8-bit data D0 "to D7" from the third D / A converter 27 are sent. As a result, from the display controller, the addresses # 1, # 3, ... Of the video memory 1 are synchronized with the clock CLK _1.
.., that is, 8-bit luminance data (Y component) and 8-bit chrominance data (BY component) are sent to the display device, and are synchronized with the clock CLK ₂ and the video memory 1 From the addresses # 1, # 4, ..., That is, 8-bit luminance data (Y component) and 8-bit chrominance data (RY component) are sent to the display device. At this time, since the clock CLK ₁ and the clock CLK ₂ are out of phase with each other by a half cycle (synchronization amount of the clock CLK ₀ ), as shown in FIG. 10B, 8-bit color difference data (BY component ) And 8-bit color difference data (RY components) are alternately sent to the display device, and 8-bit luminance gradation and 8-bit color (BY, RY) gradation are displayed on the display screen. Color display with is possible.

As described above, in the second embodiment, the gradation of the color difference data can be easily expanded and converted from 4 bits to 8 bits. Thus, for example, when it is desired to display a multi-color image such as text or graphics (when color difference gradation is not required so much), it is displayed in the video memory 1 in the form as shown in FIG. 9A. If it is sufficient to store data, and if it is desired to display a full-color image close to a natural image such as a moving image (when color difference gradation is required), the video memory 1 shown in FIG. The display data may be stored in such a model. However, when the gradation is doubled from 4 bits to 8 bits, 1
Since the display frequency for one color is halved, the resolution for color difference data is halved. However, in a full-color image such as a natural image, the frequency of the color difference component is lower than that of a multi-color image such as text or graphics, so that, for example, like a color CCD actually used in a color television camera, A sufficiently clear image can be obtained even with a resolution of half the luminance.

By the way, as described in the first embodiment, as one use of the video memory 1, when it is desired to display only multi-color images such as text and graphics on the entire display screen, the video memory 1 is used. When it is desired to store only the data of the type shown in FIG. 9A as a whole and to display a full-color image such as a moving image on the entire display screen, the data of the type shown in FIG. 9B is stored. It is possible to remember only. In this case, a flip-flop or a manual switch may be used as the switching unit 24, and the type of image may be switched in screen units by operating the switch or the like according to the type of data stored in the video memory 1. it can.

On the other hand, when it is desired to display a multi-color image such as text or graphics on a part of one display screen and a full-color image such as a moving image on another part (that is, one display screen). When you want to mix a multi-color image and a full-color image),
Data of the kind shown in FIG. 9 (a) is stored in a part of the video memory 1, and data of the kind shown in FIG. 9 (b) is stored in the other part. Can be considered. In this case, instead of a flip-flop, a manual switch, etc., as shown in FIG. 11, a switching control flag FLG is provided as attribute information in the data for one pixel of the video memory 1, and this flag FLG is set. The switching control may be performed depending on the value "1" or "0". For example, as shown in FIG. 12, when the data of a certain address in the video memory 1 is as shown in FIG. 9A, the flag FLG is set to "0" correspondingly. If the data of another address is as shown in FIG. 10A, the flag is set to "1" in correspondence with this. In this way, by setting the attribute information according to the type of display data and storing it in the video memory 1 together with the display data, the resolution in the video memory 1 is improved. Even when the multi-color data that emphasizes and the full-color data that emphasizes gradation are stored together, automatic switching control is performed according to the type of data, and a multi-color image is displayed on one screen. Full color images can be mixed.

In the example of FIG. 12, the attribute information, that is, the flag FLG is set for each pixel, but the attribute information may be set according to the coarseness of resolution of color difference data. .. That is, when the kind of pixel data is, for example, as shown in FIG. 10A, one attribute information is set in units of two pixels as shown in FIG. 13 (effective for adjacent pixels). It can also be set. In this case, 1
The amount of memory required to store the attribute information can be reduced as compared with the case where the attribute information is set for each pixel.

FIG. 14 shows a third example of the display control device according to the present invention.
It is a block diagram of the Example of. The display control device of the third embodiment has a video memory 61 in which display color data and attribute information are stored, and a coefficient table 62 in which a conversion matrix for color space conversion is stored. And a matrix multiplication unit 63 for performing a color space conversion on the display data read from the video memory 61 by applying a predetermined conversion matrix to the display data.
When one display data is read from the video memory 61, the attribute information corresponding to this display data is also read at the same time, and the predetermined conversion matrix is a coefficient based on this attribute information. It is adapted to be given from the table 62 to the matrix multiplication unit 63.

In the third display control device having such a configuration, the data for one pixel stored in the video memory 61 is stored.
24-bit display data and 4-bit attribute information D
It is assumed to be composed of 0 to D3. The following table shows an example of attribute information.

[0036]

[Table 1]

Further, a predetermined conversion matrix is stored in the coefficient table 62 in association with this attribute information. Now, the 24-bit display data stored in the video memory 61 includes 8-bit Y component (luminance component), 8-bit (RY) component (color difference component), and 8-bit (B component). -Y) component (color difference component), the attribute information (D
(0,0,0,1) is assigned as 3, D2, D1, D0). In this case, when this display data is read out from the video memory 61, its attribute information (0, 0, 0, 1) is also read out, and the coefficient table 62 converts it accordingly. The matrix is output. As a result, the matrix multiplication unit 63 causes the conversion matrix from the coefficient table 62 to act on the display data read from the video memory 61, for example, as shown in the following equation, and Y of 8 bits is used. , (RY), (BY) component display data can be converted into 8-bit R, G, B component display data.

[0038]

[Equation 1]

The 24-bit display data stored in the video memory 61 includes 8-bit Y component (luminance component), 8-bit I component (color difference component), 8-bit Q component ( (0, 0, 1, 0) is assigned to this display data as attribute information (D3, D2, D1, D0) when it is composed of color difference components). In this case, when this display data is read out from the video memory 61, its attribute information (0, 0, 1, 0) is also read out, and the coefficient table 62 converts it accordingly. The matrix is output. As a result, in the matrix multiplication unit 63, the coefficient table 6 is added to the display data read from the video memory 61, for example, as shown in the following equation.
By applying the conversion matrix from 2, the display data of each 8-bit Y, I, Q component is converted into 8-bit R, G,
It can be converted into B component display data.

[0040]

[Equation 2]

As described above, in the third embodiment, the color data is
By assigning attribute information to the data, the luminance / color difference system can be converted into the RGB system. Therefore, for example, data in different color spaces (for example, luminance / color difference system data in the video memory 61). RGB data) can be mixed, and even if they are stored in the video memory 61 in a mixed state, they are all stored in the color space (eg, RGB system) of the display device immediately before output to the display device. Data can be converted.

In each of the above-described embodiments, the case where the display control device is used for screen control of a CRT or the like has been described, but this can be applied to an output device such as a color printer in the same manner. Therefore, the display control device of the present invention is applied to a display device (including a printer and the like) in a broad sense, and it is understood that “display” includes output to a printer and the like. Should be. Further, it should be understood that the “screen” includes the meaning of the output unit to the printer and the like.

[0043]

As described above, according to the first aspect of the invention, the bit selection processing is performed on the color data for one pixel read from the storage means by mode switching by the switching means. Therefore, only one storage means, that is, the video memory is required to control the display of plural types of color data, and the video memory can be saved.

According to the second aspect of the invention, attribute information is assigned to the color data stored in the storage means, and the switching means selects the bit based on the attribute information. Since mode switching is performed, color data of different types can be mixed in one video memory, and one screen can be divided into, for example, a portion where brightness is important and a portion where color difference information is important. Can be included.

According to the third aspect of the invention, the storage means stores the luminance / color-difference color data, and the bit selection means configures the bit configuration of the luminance component and the color-difference component in the color data for one pixel. Can be changed, and when the number of bits of the luminance component is expanded, the number of bits of the color difference component is reduced by the expanded number of bits, so a simple control can produce a large luminance gradation. Display can be realized.

According to the fourth aspect of the present invention, the color data read out from the storage means is subjected to mode selection by the switching means to perform bit configuration and resolution selection processing for the color difference components. Therefore, it is necessary to perform the color data display control that emphasizes resolution and the color data display control that emphasizes color difference gradation.
Only one storage means, namely the video memory, is needed, and the video memory can be saved.

According to the invention of claim 5, the luminance / chrominance element color data stored in the storage means is
Attribute information is assigned, and the switching means performs bit configuration and resolution selection processing for color difference components based on the attribute information. Therefore, a resolution-oriented color data is stored in one video memory. Data and color data that emphasizes color difference gradation can be mixed, and a multi-color image and a full-color image can be mixed and displayed on one screen.

According to the invention of claim 6, the luminance / color difference system color data stored in the storage device is
When attribute information is assigned, one attribute information can be assigned to a plurality of pixels according to the coarseness of resolution of color data, so that the memory amount required to store the attribute information can be reduced. it can.

According to the seventh aspect of the present invention, the color data stored in the storage means is assigned attribute information corresponding to the color data, and the coefficient storage means is associated with the attribute information. When the conversion matrix is stored and the color data for one pixel is read out, the conversion matrix corresponding to the attribute information of the color data is output from the coefficient storage means and added to the operation means. Is applied to the color data to convert the color space, so even when data having different color spaces are mixed in the storage means, just before outputting them to the output device, By using the attribute information, the data can be converted into data that matches the color space of the output device.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a first embodiment of a display control device according to the present invention.

FIG. 2 is a diagram showing a configuration example of a data selector of FIG.

3 (a) and 3 (b) are diagrams showing examples of color data types, respectively.

FIG. 4 is a diagram showing a modification of the display control device of FIG.

FIG. 5 is a configuration diagram of a second embodiment of the display control device according to the present invention.

FIG. 6 is a diagram showing a configuration example of a first selector / latch unit.

FIG. 7 is a diagram showing a configuration example of a second selector / latch unit.

8A and 8B are a clock CLK and a clock C.
Is a diagram showing the relationship between the phase of the LK _2.

9A and 9B are diagrams for explaining the operation of the display control device of FIG.

10A and 10B are diagrams for explaining the operation of the display control device of FIG.

11 is a diagram showing a modification of the display control device of FIG.

12 is a diagram showing an example of flag setting in the display control device of FIG.

13 is a diagram showing an example of flag setting in the display control device of FIG.

FIG. 14 is a configuration diagram of a third embodiment of the display control device according to the present invention.

[Explanation of symbols]

 1 Video Memory 2 Data Selector 3 Switching Unit 4, 5, 6 D / A Conversion Unit 11, 12, 13 Multiplexer 21 Latch Unit 22, 23 Selector / Latch Unit 24 Switching Unit 25, 26, 27 D / A Conversion Unit 31 , 33 Latch circuit 32, 34 Multiplexer 41, 43 Latch circuit 42, 44 Multiplexer 61 Video memory 62 Coefficient table 63 Matrix multiplication unit

Claims (7)

[Claims] 1. Storage means for storing color data,
It is characterized in that it is provided with a bit selection means for performing bit selection processing on color data for one pixel read from the storage means, and a switching means for switching modes of bit selection in the bit selection means. Display controller. 2. The display control device according to claim 1,
Attribute information is assigned to the color data stored in the storage means, and the switching means performs bit selection mode switching based on the attribute information. Display control device. 3. The display control device according to claim 1,
Luminance / color difference system color data is stored in the storage means, and the bit selection means can change the bit configuration of the luminance component and the color difference component in the color data for one pixel by the control of the switching means. When the number of bits of the luminance component is expanded, the number of bits of the color difference component is reduced by the expanded number of bits. 4. Storage means for storing color data of luminance / color difference system, and color difference component control means for performing selection processing of bit configuration and resolution for the color difference component of the color data read from the storage means. A display control device comprising: a bit configuration in color difference component control means and a switching device for switching modes for resolution selection. 5. The display control device according to claim 4,
Attribute information is assigned to the color data of the luminance / color difference system stored in the storage means,
The display control device is characterized in that the switching means performs selection processing of a bit configuration and resolution for a color difference component of luminance / color difference type color data based on the attribute information. 6. The display control device according to claim 5,
When assigning attribute information to the luminance / color difference type color data stored in the storage means, it is possible to assign one attribute information to a plurality of pixels according to the coarseness of resolution of the color data. A display control device characterized by: 7. Storage means for storing color data,
The storage means includes a coefficient storage means for storing a color space conversion matrix, and an operation means for applying a predetermined conversion matrix to the color data read from the storage means to convert the color space. Attribute information is assigned to the color data stored in the memory, and the conversion matrix is stored in the coefficient storage means in association with the attribute information, and the color data for one pixel is read out. In some cases, the coefficient storage means outputs a conversion matrix corresponding to the attribute information of the color data, and the conversion matrix is added to the calculation means.