JPH10214077A - Method for generating synthetic plotting data and synthetic plotting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the generating method for synthetic plotting data which generates α data used to put a color plotting image together with a video signal with high quality at a high speed, and the synthetic plotting device. SOLUTION: A CPU 101 expands the plotting image to be put together with necessary precision and plats it in an enlargement area formed on a RAM 103 as a black-and-white bit map. Consequently, a plotting image which is plotted to one dot of the plotting image of the original size is plotted in a unit area formed of more than one dots in the enlargement area. Black dots are counted by unit area and α data by the unit areas are generated according to the number of black dots. The α data are stored in a VRAM 15. The αdata are supplied to a digital video mixer 21 together with luminance information and color difference information to put the plotting image of high quality after anti-aliasing at a high speed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for generating and drawing synthetic drawing data used for generating a drawing image such as a character, a figure, a symbol, etc., which is synthesized with a display image based on a television signal or the like. The present invention relates to a composite drawing apparatus.

[0002]

2. Description of the Related Art For example, when a drawn image such as a character or a figure is combined with a moving image such as a title displayed on a display screen of a television program or a subtitle of a movie, a so-called video terrorist or titler is used. A device for generating combined drawing data is used.

In such an apparatus for generating composite drawing data, for example, FIG.
As shown in FIG. 1, a drawn image (FIG. 1) such as a character or a figure to be synthesized with a moving image (FIG.
OA). The drawn image is generated using, for example, a font included in the synthetic drawing data generating device.

[0004] The drawing image generated by this font is
Even if it has a high resolution, when it is displayed by being synthesized with a video signal, a drawn image is formed by a finite number of dots (pixels) constituting a screen. The edge portion may be “jagged,” and the drawn image may have a strange feeling.

[0005] Therefore, a so-called anti-aliasing technique is used to generate a drawn image in order to smooth the edges of the drawn image to be synthesized and to generate a high-quality drawn image. This method is to increase the apparent resolution by using an intermediate value for the composition ratio of a video signal composed of certain finite dots. With this anti-aliasing method, it is possible to suppress the occurrence of “jaggies” at the edges of the characters.

[0006] In the case of a commercial (broadcasting) synthetic drawing data generating apparatus, most synthesized characters are synthesized with smooth characters by the anti-aliasing technique. In recent years, this anti-aliasing method has been used even for consumer equipment in order to draw higher quality images.

When the anti-aliasing method is used, in addition to the drawn image data of drawn characters, figures, symbols, and the like (called objects), α data which is information mainly indicating the composition ratio of the object and the background image is used. Generate contour data called.

The contour data (hereinafter referred to as α data)
In order to generate, the color drawing image of the object is, for each drawing minimum unit area (corresponding to the pixel dot area),
It is divided into N (N is an integer of 2 or more) regions, and for each of the divided regions, a region that is included in an object and that actually performs drawing (this is referred to as a substantial drawing region in this specification) ) Is determined, and for the contour portion of the object, the area ratio of the substantial drawing area to the minimum drawing unit area is calculated based on the number of the minimum drawing unit areas in the divided area where the drawing is performed, and is set as α data.

In practice, since the minimum drawing unit area corresponds to an image dot, the system executes processing in image dot units. Therefore, the color drawing image is drawn in an area enlarged to be N times the minimum drawing unit area so that the divided area has the size of the minimum drawing unit area. For each N-times unit area, the area ratio of the substantial drawing area for each of the minimum drawing unit areas is obtained, and the α data is obtained.

When the base video image and the drawing image such as characters and figures are synthesized, the outline portion of the drawing image is converted to the base image at a synthesis ratio determined by the α data obtained as described above. , The jaggedness at the edges of the drawn image can be suppressed, the apparent resolution can be increased, and the drawn image such as characters and figures can be generated as a smooth, high-quality image.

[0011]

By the way, in the conventional synthetic drawing data generating apparatus, when calculating the .alpha. Data, a color drawing image is drawn in the above-mentioned enlarged area on a memory, and the original image is generated. The number of actual drawing areas is counted for each area corresponding to the minimum drawing unit area.

For example, the minimum drawing unit area is a pixel dot, and for each dot, in order to obtain an area ratio indicating a ratio occupied by a drawn image, an enlarged area, for example, quadrupled, is formed on a memory. When a drawn image enlarged based on the drawn image data is formed in the enlarged area, in the four-dot area corresponding to the minimum drawing unit area of the original image, dots used to form the drawn image, that is, colors The area ratio is calculated by counting the number of dots marked with, and dividing the number of dots by four.

In the case of the conventional apparatus, when calculating the area ratio, the drawn image is formed in an enlarged area on the memory as a full color or a color image having a large number of colors equivalent thereto. For example, red (R) forming a color image,
If each of the green (G) and blue (B) color information is represented by 8 bits, there is 24-bit color information for each dot of the enlarged area where the drawn image is formed.

Therefore, when counting the number of color dots, a plurality of bits must be handled. in this way,
When a drawn image is treated as a color image, the amount of information increases, so that the number of dots that can be processed at one time is small, and the number of loops in software processing increases, and the drawing area described above is configured. The process of obtaining the area ratio indicating the ratio of the drawn image for each dot cannot be performed at high speed.

Therefore, as another method of generating a high-quality drawn image, a large number of bitmap fonts corresponding to each resolution are prepared, and α data for anti-aliasing is prepared in advance according to the resolution at the time of displaying the drawn image. It has also been proposed that the results be used when needed.

However, in this case, since the resulting data is bitmap data, the storage capacity becomes extremely large, and the auxiliary storage device such as a hard disk is pressed, which is not preferable.

In addition, for example, a quadratic spline curve (S = generating point, Pi = coefficient vector, t = parameter) shown in FIG. 11 and a cubic Bezier curve (S = generating point, Pi = Feature point, t = parameter, nCi = binomial coefficient)
There is also a method of directly obtaining α data by using an equation constituting an outline font such as the above.

However, in a device for generating a composite drawing image, the drawing speed of characters and the like is an important problem in terms of the performance of the device and the operating system that operates the device, and usually, font data is used. Software that generates drawing images such as characters at high speed is prepared in advance.

As described above, it is very difficult to develop software that generates high-quality drawn images equivalent to or faster than software prepared in advance that can draw characters and the like at high speed. In some cases, it is not permitted to directly use font data provided in a synthetic drawing data generation device or an operating system for operating the synthetic drawing data generation device. It is difficult to develop wear independently.

In view of the above, the present invention provides a method and an apparatus for generating synthetic drawing data capable of generating high-quality and high-speed drawn images such as characters, figures, and symbols to be synthesized on a display screen. The purpose is to:

[0021]

According to a first aspect of the present invention, there is provided a method for generating combined drawing data, comprising combining a display image with a color drawing image such as a character or a figure. Therefore, a method of generating composite drawing data consisting of color drawing image data and outline data used to synthesize the color drawing image with the display image, wherein the color drawing image is a black and white image. For each drawing minimum unit area, an area ratio of a substantial drawing area for each drawing minimum unit area is determined, and the contour data is generated based on the area ratio.

According to a second aspect of the present invention, there is provided a method of generating composite drawing data, the method comprising the steps of: By preparing a conversion table formed by associating a pattern with information for obtaining an area ratio corresponding to this pattern, and referring to the conversion table, the actual drawing area in the minimum drawing unit area is prepared. The area ratio is obtained based on the pattern of (1).

According to a third aspect of the present invention, there is provided a method of generating composite drawing data according to the first or second aspect, wherein the black-and-white image is the black-and-white image. Is drawn in an enlarged area expanded so that the drawing minimum unit area is N (N is an integer) times the drawing minimum unit area of the color drawing image. An area ratio of a substantial drawing area for each of the minimum drawing unit areas is obtained for each of N times the minimum drawing unit area.

According to the first aspect of the present invention, a color drawing image is processed as a black and white image, and a substantially drawn image area for forming a black and white image for each drawing minimum unit area. Are determined. Α data (contour data) is generated based on the area ratio.

In this case, since the color drawing image is processed as a black-and-white image, it is not necessary to process color information, and the amount of information to be processed is reduced.

As a result, the area ratio of the substantial drawing area can be obtained at high speed for each drawing minimum unit area, and α data can be generated at high speed in accordance with the obtained area ratio.

According to a second aspect of the present invention, a pattern of a substantial drawing area in a minimum drawing unit area and α data of a substantial drawing area for the minimum drawing unit area are obtained. A conversion table formed in association with data for the conversion is prepared in advance.

Then, the pattern of the substantial drawing area is read for each drawing minimum unit area, and a conversion table is referenced based on the read pattern to obtain data for obtaining α data. Data is required.

In this case, the area ratio with respect to the minimum drawing unit area can be obtained without dividing the substantial drawing area (area) in the minimum drawing unit area by the minimum drawing unit area (area).

This eliminates the need for time-consuming division and other processing, so that the area ratio of the real drawing area to the minimum drawing unit area can be obtained at a high speed, and the α data can be calculated based on the obtained area ratio. Can also be generated at high speed.

According to the third aspect of the present invention, a minimum drawing area of a monochrome image is N times as large as a minimum drawing area of a color drawing image. It is drawn as if it were enlarged.

As a result, the area ratio of the minimum unit area for drawing a black-and-white image is equal to the area ratio of the minimum unit area for drawing a color image which is N times the unit area used for drawing a black-and-white image. It can be obtained by counting the number of minimum unit areas. Therefore, by calculating the area ratio for each unit area, the area ratio of the substantial drawing area for each black and white image drawing minimum unit area is obtained,
Α data is obtained based on this area ratio.

[0033]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a method for generating combined drawing data and a combined drawing apparatus according to the present invention will be described with reference to the drawings.

In the embodiment described below, the composite drawing apparatus can perform two types of anti-aliasing. One is so-called video anti-aliasing, which displays a smooth drawn image by using the combination ratio of a plane of a drawn image such as a character or a figure and a plane of a background such as a moving image to be synthesized as α data. I do.

The other anti-aliasing is so-called CG anti-aliasing. For example, a boundary between a drawn image of a character or the like and an edge (edge) attached to the drawn image or an overlapping portion of the drawn image of a character or the like is as follows. The color of the relevant portion is determined according to the α data, not the combination ratio. That is, the portion between the character drawing image and the edge (edge) is represented by an intermediate color corresponding to the α data between the color of the character body and the color of the edge portion. In addition, the boundary between drawn images such as overlapping characters is drawn in an intermediate color between the two according to the α data, so that a smooth drawn image is displayed.

Therefore, in the combined drawing apparatus of the embodiment described below, the α data is used for two kinds of anti-aliasing, that is, video anti-aliasing and CG anti-aliasing.

[First Embodiment] FIG. 1 is a block diagram for explaining a composite drawing apparatus 1 according to this embodiment. The composite drawing device 1 includes a part of a composite drawing data generation device.

The synthetic drawing apparatus 1 of the example shown in FIG. 1 transfers a drawing data composed of a synthetic drawing data generator 100 composed of a computer, a graphic accelerator 12, and video RAMs (hereinafter, referred to as VRAMs) 13, 14, and 15. A buffer section 11, a digital video mixer 21 for synthesizing the generated color drawing image data and input video image data described later, and a key signal controller 2
2, an external video signal input terminal 31, an A / D conversion circuit 32, D / A conversion circuits 33 and 34, and an output terminal 4.
1, 42, and 43.

As shown in FIG. 1, the combined drawing data generation unit 100 includes a CPU 101, a ROM 102, a RAM 10
3, VRAM 104, display controller 105
, And are connected via a system bus 109. The display 2 is connected to the display controller 105. Further, the keyboard 3 and the mouse 4 for receiving drawing input information from the user are connected to the system bus 1 via the I / O port 112.
09.

The ROM 102 stores various information used in the composite drawing apparatus 1 of this embodiment, such as font data such as characters, figures, and symbols, and programs. The RAM 103 is used as a work area for various processes, and the VRAM 104 is a display memory used for displaying the generated drawn image.

Then, the composite drawing data generation unit 100
In accordance with drawing input information from a user input via the keyboard 3 or the mouse 4, a color drawing image such as a character or a figure to be synthesized with a color video signal input through the input terminal 31 is prepared in advance in, for example, the ROM 102. Is drawn using the existing font rasterizer and graphic drawing routine.

In this case, the color drawing image corresponding to the drawing input information from the user is drawn in the VRAM 104. V
The color drawing image drawn on the RAM 104 is
In response to the instruction 1, the display controller 105 reads the information and displays it on the display 2.

When the color drawing image displayed on the display 2 is a drawing image intended by the user,
The user performs a confirmation input via the keyboard 3 or the mouse 4. This confirmation input is, for example, pressing a preview button key on a keyboard or selecting a preview icon displayed on the screen of the display 2 with a mouse.

At this time, if the color drawing image displayed on the display 2 is not the one intended by the user, the user inputs a drawing instruction, so that the color drawing image corresponding to the new drawing instruction is input. It can be drawn and displayed on the display 2.

When the user performs a confirmation input, the CP
U101 detects this, uses the RAM 103 as a work area, and draws a color drawing image as a black-and-white drawing image, as will be described in detail later, and for each pixel dot which is a drawing minimum unit area of the black-and-white drawing image, The area ratio of the substantial drawing area is obtained, and α data is generated.

Then, the CPU 101 sets the VRAM 104
Based on the color drawing image drawn in the drawing, drawing data consisting of three color signals of red (R), green (G), and blue (B) is supplied to the graphic accelerator 12 via the I / O port 111 and , And supplies the generated α data to the graphic accelerator 12 via the I / O port 111.

In this embodiment, each of the R, G and B primary color signals is represented by 8 bits. The α data is represented by the number of bits according to the precision of the anti-aliasing.

The graphic accelerator 12 has R,
A luminance signal (Y) and a color difference signal (U / V) are generated based on the G and B primary color signals. In this case, the luminance signal (Y) and the color difference signal (U / V) are each represented by 8 bits.

Then, the graphic accelerator 12
Represents the generated luminance signal (Y) and color difference signal (U / V) as V
The data is written to the RAM 13 and the VRAM 14 and the α data is written to the VRAM 15.

VRAM13, VRAM14, VRAM1
For example, the luminance signal, the color difference signal, and the α data that form a color drawing image for one screen, which are written into the digital video mixer 21, are read out and supplied to the digital video mixer 21.

The digital video mixer 21 has an input terminal 3
1, a color drawing image formed by a luminance signal (Y) and a color difference signal (U / V) is
Based on the α data read from the RAM 15, the above-described video anti-aliasing is performed to synthesize. The video signal that has undergone the video anti-aliasing and is combined with the color drawing image is D / A converted by the D / A conversion circuit 21a, output via the output terminal 43, and supplied to a device such as a monitor receiver. You.

The composite drawing apparatus 1 according to this embodiment
The luminance signal (Y) and the luminance signal (Y) are considered in consideration of combining an image signal and a color drawing image by performing anti-aliasing according to an area ratio obtained by the combining and drawing apparatus 1 using a switcher or the like provided outside. Color difference signal (U / V)
Image data formed by the D / A conversion circuit 32
, And after being converted to an analog signal, can be output to the outside via an output terminal 42.

In this case, α written in the VRAM 15
The data is read from the VRAM 15 and supplied to the key signal controller 16, where it is converted into a key signal used to combine the color drawing image with the video signal,
It is output to the outside via the output terminal 41.

Thus, as shown in FIG. 2, the switcher 5 has a function of synthesizing a color drawing image with a video signal in accordance with a key signal. The output key signal is supplied through the input terminal 51 of the switcher 5. The drawing data output through the output terminal 42 of the combined drawing device 1 is supplied through the input terminal 52 of the switcher 5.

The video signal input from the video signal input terminal 53 of the switcher 5, the drawn image data, and the key signal are supplied to the synthesizing circuit 54 of the switcher 5. The synthesizing circuit 54 controls the synthesizing ratio of the color drawing image formed by the drawing data in accordance with the key signal from the input terminal 51, and converts the video signal supplied from the input terminal 53 into the drawing signal from the input terminal 52. The color drawing image formed by the data is synthesized by being anti-aliased.

The color drawing image is output from the synthesizing circuit 54 via the output terminal 55 of the switcher 5 and supplied to a monitor receiver or the like.

Next, a description will be given of a process of generating α data used for anti-aliasing, which is performed in the composite drawing apparatus 1 of this embodiment. In the combined drawing apparatus 1 of this embodiment, the combined drawing data generation unit 100 can quickly generate α data used for anti-aliasing.

As described above, when the CPU 101 detects, for example, that the preview button key on the keyboard is pressed or that the preview icon displayed on the screen of the display 2 is selected by the mouse, the CPU 101 reads the ROM.
A color drawing image is drawn as a black-and-white image by using an existing drawing routine for a black-and-white bitmap prepared in advance in 102.

In this case, the CPU 101 uses the drawing data for forming the color drawing image as black-and-white data, and draws a drawing image enlarged, for example, twice vertically and horizontally in the RAM 103 in this embodiment. The magnification of the drawn image is determined according to the accuracy of the anti-aliasing.

As described above, the CPU 101
3, an enlarged area is formed as a black and white bitmap for drawing an enlarged black and white image, and a black and white drawing image is drawn using this enlarged area as a so-called canvas.

The monochrome bit map indicates whether one pixel dot (hereinafter, simply referred to as a dot) is white or black (whether or not it is colored), and each dot corresponds to one bit. It is. Therefore, in the black and white bitmap, one dot can be represented by one bit, and
Since one dot is one byte, the efficiency of use of the memory is good, and the processing efficiency of the CPU 101 is also good.

For example, when the drawing input information from the user indicates that the character “A” is to be drawn, the CPU 101 stores, in the RAM 103, a double-sized black and white drawing as shown in FIG. Draw an image.

In this case, since the drawn black-and-white image is doubled both vertically and horizontally, as shown in FIG. 3B, which is a partially enlarged view of FIG. 3A, one dot of the original original drawn image is , Are drawn in a unit area composed of four dots, two dots each in the vertical and horizontal directions.

The black-and-white drawing image is drawn in an enlarged manner as described above, and the area ratio of the substantial drawing area to each unit area constituting the enlarged area in which the enlarged drawing image is drawn is obtained, thereby obtaining the original drawing. The α data can be generated by calculating the area ratio for each dot as the minimum drawing area of the image.

For example, if the number of dots (substantial drawing area) actually used to form a black-and-white drawn image in a unit area of 4 dots of 2 dots vertically and horizontally is one dot, The area ratio, which is the ratio of the drawn image to the unit region formed by 4 dots, is 25% (α
= 0.25).

Similarly, when the number of dots used to form a drawn image is 2 in the unit area formed by the four dots, the area ratio is 50% (α =
0.5), when the number of used dots is 3, the area ratio is 75% (α = 0.75), and when the number of used dots is 4, the area ratio is 100% (α). = 1)
Can be determined.

As described above, the area ratio of the substantial drawing area to the unit area composed of 4 dots of 2 dots vertically and horizontally is the area ratio of 1 dot as the minimum drawing unit area of the original drawn image. Become. Then, an area ratio is obtained for each of the unit areas of the enlarged area on which the enlarged image is drawn, and α data can be generated based on the obtained area ratios.

In this case, the enlarged image drawn in the enlarged area formed in the RAM 103 is, as described above,
Since it is rendered using black and white data, it has no information about colors. Therefore, the CPU 101 enlarges and draws the drawn image in the enlarged area formed in the RAM 103, and according to the number of dots used to form the drawn image for each unit area formed of 4 dots, The α ratio can be generated by determining the area ratio.

Therefore, as shown in FIG. 3B, each dot (minimum drawing unit area) in the case where a drawn image of the original size is formed without being enlarged by using the drawn image enlarged twice in length and width. Can be obtained as shown in FIG. 4A. In this case, a dot having a large α data has a large portion of a drawn image, and a dot having a small α data has a small drawing portion.

The black and white bitmap is a drawing method which simulates drawing characters and the like on paper with a pen.
In the enlarged drawing area as a black and white bitmap formed on the image 103, the drawn image portion is drawn so as to be black as shown in FIGS. 3A, 3B, and 4A.

Generally, as described above, in the case of video anti-aliasing, as shown in FIG. 4B, when the value of α data is large, a large portion of the drawn image is displayed, and when the value of α data is small, the background of the background is displayed. It takes the form that many parts are displayed.

In this embodiment, only the drawn image is displayed on the dot having the α data of 100% (α = 1), and the dot having the α data of 0% (α = 0) remains as the background. Becomes For other dots, the composition ratio of the drawn image is adjusted in accordance with the α data, and as shown in FIG. 4C, the anti-aliased high-quality drawn image from which the jaggedness at the edges of the drawn image has been removed. Can be generated.

Next, with reference to the flowchart shown in FIG. 5, the generation processing of α data in the composite drawing data generation unit 100 will be described.

As described above, a color drawing image corresponding to the drawing input information is formed in the VRAM 104 by the user, and after this is displayed on the display 2, confirmation input such as pressing of a preview button key is performed. Then, the CPU 101 executes the α data generation processing shown in FIG.

First, the CPU 101 draws a target drawn image (object) in black and white at a magnification corresponding to the anti-aliasing accuracy (step 201). This first
In the embodiment, the drawn image enlarged twice in length and width by the processing in step 201 is stored in the RAM 103.
A black and white image is drawn in an enlarged area formed as a black and white bitmap.

Next, the CPU 101 reads the data of the unit area in the enlarged area formed as a black and white bitmap (step 202), and counts the number of black dots in the unit area (step 203).

Then, based on the number of black dots in the unit area obtained by the processing in step 203, the area ratio indicating the ratio of the drawn image to the unit area is obtained, and α data is generated (step 204).

Next, it is determined whether or not the area ratio has been calculated for all of the unit areas constituting the enlarged and drawn image (step 205). This determination process is a process of determining whether α data has been obtained for all the dots in the drawing area where the drawn image is formed, when the drawn image of the original size is drawn.

If it is determined in step 205 that α data has not been obtained for all the unit areas, the data reading position is positioned in the next unit area (step 206), and the processing from step 202 onwards. repeat.

Further, in the judgment processing of step 205, α is set for all the unit areas constituting the enlarged area.
When it is determined that data has been obtained, the process of generating α data for all the dots constituting the drawn image is terminated.

As described above, in the composite drawing apparatus 1 of this embodiment, the drawn image is drawn in an enlarged area as a monochrome bitmap in which one dot can correspond to one bit, and the drawn image is drawn. By calculating the area ratio for each unit region constituting the region, α data is generated for each dot in the drawing region where the original drawn image is formed.

As described above, by using a monochrome bitmap in which one dot can correspond to one bit, a drawn image is drawn as a conventional color image, and each of the drawing regions forming the drawn image is drawn. Compared to the case where α data is generated in a state where the amount of information accompanied by color information for each dot is large,
The amount of information to be processed is very small. This gives α
Data can be generated at high speed, anti-aliasing can be performed quickly, and a high-quality drawn image can be combined with a video signal.

In the first embodiment,
The drawn image is enlarged twice in length and width, and α data is determined using a region formed by four dots of two dots in length and width as a unit region. In this case, the α data for each unit area is 2
It can be expressed in bits (2-bit anti-aliasing).

However, the present invention is not limited to this. For example, a drawn image is enlarged four times (4 × 4) both vertically and horizontally, and 4-bit anti-aliasing is performed in which an area formed by 16 dots of 4 dots × 4 dots is used as a unit area to express α data in 4 bits. You can also

Similarly, the drawn image is enlarged by 16 times both vertically and horizontally (16 ×
It is possible to perform 8-bit anti-aliasing that expands to 16) and 10-bit anti-aliasing that expands 32 times (32 × 32) both vertically and horizontally. That is, the enlargement ratio of the drawn image can be selected according to the accuracy (quality) of the target anti-aliasing.

Further, the composite drawing apparatus 1 of this embodiment
For example, an image based on a color video signal can be transmitted through a portion of a drawn image to be synthesized with a color video signal. When transmitting a so-called background image by a color video signal to the drawn image portion, the user sets the background transmittance in a memory such as the RAM 103 of the combined drawing data generation unit 100 in advance via the keyboard 3. deep.

As described above, when generating the α data, the predetermined transmittance is also taken into consideration.
Generate α data. As described above, the combined drawing apparatus according to the present embodiment can generate α data according to the area ratio determined for each drawing minimum unit region and the instruction information from the user.

[Second Embodiment] Next, a method of generating combined drawing data and a second embodiment of a combined drawing apparatus according to the present invention will be described.
An embodiment will be described.

In the second embodiment, attention is paid to drawing an enlarged drawn image on a black and white bitmap, and a black and white drawing pattern when a drawn image is formed on an enlarged area (black and white bitmap). By preparing a conversion table between .alpha. Data and .alpha. Data in advance, .alpha. Data can be generated even faster.

The composite drawing apparatus according to the second embodiment comprises:
This is the same as the composite drawing apparatus 1 of the first embodiment described above with reference to FIG. Therefore, the description will be made assuming that the composite drawing apparatus according to the second embodiment has the configuration shown in FIG.

In the combined drawing apparatus 1 according to the second embodiment, the ROM 102 of the combined drawing data generation unit 100 stores pattern data of a monochrome bitmap in which an enlarged drawn image is drawn, and corresponding α There is provided a conversion table formed by associating data for obtaining data.

FIG. 6 is a diagram for explaining a conversion table between a drawing pattern on a monochrome bitmap and α data used in the second embodiment. In the second embodiment, the drawn image is enlarged vertically and horizontally by 8 times (8 × 8 times).
An example of the case of 6-bit anti-aliasing, which expands to.

Therefore, in the second embodiment, the drawn image drawn in one bit of the original size drawn image is drawn in an area formed by 64 bits of 8 bits × 8 bits. That is. In the second embodiment, a region formed by 64 bits of 8 bits × 8 bits is a unit region.

This unit area can be considered to be formed by an area of eight dots in the horizontal direction being collected in eight stages in the vertical direction. As described above, in the case of a black-and-white bitmap, one dot can be represented by one bit. Therefore, in the second embodiment, one horizontal row of eight dots is converted into one-byte data at a time. Can read and write.

Therefore, as shown in FIG.
In the embodiment, a conversion table is formed by a drawing pattern of 8 dots in one horizontal row and an α data output corresponding to the drawing pattern.

In this case, when the drawing image is drawn in the unit area consisting of 64 dots, the drawing pattern formed by 8 dots in one horizontal row is represented by a hexadecimal number of 00h.
(H indicates hexadecimal notation; the same applies hereinafter) to FFh. Therefore, a drawing pattern that can be represented by eight dots in one horizontal row of the unit area is represented by a binary number of 00000000 to 11111111 if it is represented by a binary number so as to match the image of the dot pattern.
There are 56 ways.

For this reason, in the ROM 102 of the composite drawing data generation unit 100, a conversion table including each drawing pattern from 00h to FFh and the corresponding α data output is created and recorded in advance.

Also, in the second embodiment, 8
The α data output corresponding to the dot drawing pattern should be set to the number of black dots in the read drawing pattern in order to match the dynamic range of the required α data in advance. (Multiplier) is set.

In the second embodiment, the α data output is set to a value when the dynamic range of the α data is 9 bits. Therefore,
In the second embodiment, since the dynamic range of the α data is 9 bits because of the 6-bit anti-aliasing and the dynamic range of the α data is 9 bits, as shown in FIG. Is the α data output.

Thus, the conversion table used in the second embodiment is 6-bit anti-aliasing, and when α data is expressed in hexadecimal, α
When the data is 100h, it is all characters.
In the case of 0h, it is possible to obtain α data that is all the background part.

Therefore, the CPU 101 multiplies the α data of the unit area obtained from the α data output corresponding to the read drawing pattern by a predetermined value, thereby obtaining the dynamic data of the finally required α data. There is no need to perform processing to match the range.

Then, as in the case of the composite drawing apparatus 1 of the first embodiment, the CPU 101 of the composite drawing data generation unit 100 responds to drawing input information from the user.
Generates a color drawing image in the VRAM 104 using, for example, font data recorded in the ROM 102. The color drawing image generated in the VRAM 104 is read by the display controller 105 and displayed on the display 2. The user checks the color drawing image displayed on the display 2, and when the drawing image is the target drawing image, for example, presses a preview button key or selects a preview icon.

When the CPU 101 detects that the user presses the preview button key or selects the preview icon, the CPU 101 uses the color drawing data of the color drawing image formed in the VRAM 104 as the black and white drawing data, and RAM with 8x enlarged image
The image is drawn in an enlarged area as a black-and-white bit map formed in 103.

Then, in the second embodiment,
The CPU 101 of the combined drawing data generation unit 100 reads a drawing pattern for each unit area constituting the enlarged area and for every eight dots (one byte) in one horizontal row of the unit area.

That is, 8 dots ××
For example, when a drawn image is drawn in a unit area consisting of 64 dots of 8 dots as shown in FIG.
01 reads a drawing pattern from a unit area in units of 8 dots (1 byte) in one horizontal row. In this case, as shown in FIG. 6, “11000011”, “1000011”
The drawing pattern is read for each horizontal row of the unit area, such as “1”, “11000001”.

Then, the CPU 101 obtains a corresponding α data output by referring to the conversion table recorded in the ROM 102 based on the read drawing pattern. As a result, as shown in FIG.
For "00011" and "100000111," a value of 16 is obtained as the alpha data output, and when the drawing pattern is "11000001" or "11100000", a value of 20 is obtained as the alpha data output.

As described above, based on the drawing pattern of one horizontal row of the unit area, an α data output is obtained for each horizontal row of the unit area. Then, by adding all the α data outputs for each area of 8 dots in the horizontal direction of the unit area,
Α data for the enlarged area is obtained.

That is, in the second embodiment, since all the α data outputs shown in FIG. 6 may be added, 16 + 16 + 20 + 20 + 16 + 16 + 24 + 24 = 152 (152), which is expressed as a hexadecimal number of 98h Becomes

Also, the α data is obtained by multiplying the number of black dots in the unit area by a magnification for adjusting to the required dynamic range of the α data in advance and dividing this by the total number of dots in the unit area. Can be. When this calculation is applied to the example shown in FIG. 6, the following equation is obtained: 38 × 256 ÷ 64 = 152 = 98h (2)

Thus, it can be seen that the same result is obtained regardless of which method is used to obtain the α data. As is apparent from the above equations (1) and (2), in the second embodiment, without performing division and multiplication,
The α data with respect to the unit area can be obtained only by the addition operation.

Then, α data obtained for each unit area constituting the enlarged area where the enlarged drawing image is drawn, and
For example, the R, G, and B primary color signals of the drawn image are captured by the graphic accelerator 12, and the first
As in the case of the synthetic drawing apparatus 1 of the embodiment, the area ratio is VR
The luminance signal generated based on the primary color signal is written to the VRAM 13 and the color difference signal is written to the VRAM 14 in the AM 15.

The VRAMs 13, 14, 15
Is supplied to the digital video mixer 21 and is synthesized by being anti-aliased with a color video signal, or the α data is converted into a key signal. Output from the drawing device.

Next, with reference to the flowchart shown in FIG. 7, a description will be given of the process of generating α data in the composite drawing data generation unit 100 of the composite drawing apparatus according to the second embodiment.

As in the case of the first embodiment, the color drawing image corresponding to the drawing input information from the user is stored in the VRAM 10.
4 is displayed on the display 2, and when a confirmation input such as pressing of a preview button key is performed, the CPU 101 executes α data generation processing shown in FIG.

First, the CPU 101 creates a conversion table according to the accuracy of the anti-aliasing (step 3).
01). If the conversion table is created once when the composite drawing apparatus according to the second embodiment is started, it is not necessary to recreate the conversion table every time anti-aliasing processing is performed. Therefore, if the necessary conversion table has already been created, the processing of step 301 is prevented from being repeated. Next, the CPU 101 sets the desired drawn image (object) at the required magnification ratio.
Is drawn on the RAM 103 as a monochrome bitmap (step 302). Then, the CPU 101 enlarges the area (black and white bitmap) in which the enlarged drawing image is drawn.
Is read (step 303), and based on the read drawing pattern, an α data output is obtained by referring to the conversion table created in step 301 (step 304).

Of course, the conversion table referred to in step 303 is not limited to the conversion table created by the processing of step 301, but may be a conversion table created by the previous processing.

The α data outputs obtained by the processing of step 304 are sequentially added to obtain α data of the unit area (step 305).

Next, it is determined whether or not the α data has been calculated for all of the unit areas constituting the enlarged and drawn image (step 306). The determination process in step 306 is to determine whether the area ratio of the drawn image to all the dots in the drawing area where the drawn image is formed is obtained when the drawn image is drawn at the original size without being enlarged. This is the process of determining.

If it is determined in step 306 that α data has not been obtained for all the unit areas, the data reading position is positioned in the next unit area, and the processing from step 303 is repeated.

If it is determined in step 306 that α data has been obtained for all the unit areas, the α data generation processing ends.

As described above, in the composite drawing apparatus according to the second embodiment, the enlarged drawing image is drawn in the enlarged area as a black and white bitmap, and the drawing pattern of the unit area constituting the enlarged area is A conversion table including the corresponding α data output is prepared in advance.

As a result, it is possible to obtain the α data for the unit area by reading the drawing pattern formed on the unit area, obtaining the α data output based on the read drawing pattern, and adding them. it can.

That is, in this case, the α data can be obtained without performing a time-consuming operation such as multiplication or division. Further, since the α data output can be obtained based on the drawing pattern, the process is not performed for each dot constituting the unit area, so that the α data can be quickly obtained for each unit area.

Therefore, the area ratio of each dot forming the target drawn image can be obtained at a higher speed, and anti-aliasing can be performed to generate a high-quality drawn image. In the control unit 100 according to the second embodiment, access to the RAM 103 in which a monochrome bitmap is stored (data reading), access to the ROM 102 in which a conversion table is stored (data reading),
The area ratio can be obtained at high speed by a combination of simple and high-speed processing such as addition of α data output and storage of area ratio for each unit area (data writing).

As described above, since only simple processing is performed, for example, when a cache memory is mounted, it is necessary to effectively use the cache memory and efficiently operate the advance control called a pipeline. Can be. Also in this case, the speed of α data and the speed of anti-aliasing can be increased.

Note that in the second embodiment,
Enlarge the drawing image 8 times vertically and horizontally, 64 dots of 8 dots vertically and horizontally.
6-bit anti-aliasing for obtaining α data using a region formed by dots as a unit region was performed.

However, the present invention is not limited to this. For example, a 4-bit anti-aliasing that expands 4 times (4 × 4) both vertically and horizontally, an 8-bit anti-aliasing that expands 16 times (16 × 16) both vertically and horizontally, and 32 times (32 × 3) both vertically and horizontally
As in the case of performing 10-bit anti-aliasing to enlarge in 2), the enlargement ratio of the drawn image can be selected according to the target anti-aliasing accuracy.

Further, the conversion table is, as described above,
There is no limitation to the case where the unit area is formed in accordance with the drawing pattern of each horizontal row. For example, a conversion table including drawing patterns of drawing images drawn in one unit area and α data corresponding to these drawing patterns may be formed.

The order of accessing the black-and-white bitmap when reading a drawing pattern is determined by several methods in consideration of the characteristics of the CPU, the accuracy of anti-aliasing, and the processing speed by using a cache memory or the like. Can be selected.

FIG. 8 is a diagram for explaining an example of the access order to the monochrome bitmap. This method is a method used in the case of the above-described second embodiment, and is a case in which α data for a unit area is obtained at once for a target unit area, as indicated by an arrow in FIG. .

In the case of this method, although the addresses of the monochrome bitmap are not continuous, it is not necessary to hold the α data output obtained by referring to the conversion table in a register or the like. There is an advantage that you can go.

FIG. 9 is a diagram for explaining another example of the access order to the monochrome bitmap. This method is illustrated in FIG.
As shown by the arrow in FIG. 7, the access is performed in the order of addresses of the memory in which the monochrome bitmap is formed. In the case of this method, the address of the black-and-white bitmap can be obtained by simply adding a fixed value (increment instruction).

Since the addresses of the black and white bitmap are continuous, if the data cache memory is used, the target drawing pattern is obtained from the black and white bitmap developed in the data cache memory. The probability that the process can be performed is increased, leading to a reduction in processing time.

The CPU has two bytes (word), four bytes,
When a memory access instruction in a byte (double word) is provided, a plurality of unit areas (monochrome bitmap) can be simultaneously accessed to calculate an area ratio for a plurality of dots. In this case, there is an advantage that the number of accesses to the RAM on which the monochrome bitmap is formed is reduced, and the processing speed is increased.

The method is not limited to these methods.
Various methods of accessing the memory can be used.
Therefore, as described above, an appropriate access method is selected according to conditions such as CPU characteristics and anti-aliasing accuracy.

[0136]

As described above, according to the method of generating composite drawing data and the composite drawing measure according to the present invention,
Α data can be obtained at high speed. As a result, anti-aliasing can be performed, and a high-quality drawn image can be quickly synthesized with a color video signal.

[Brief description of the drawings]

FIG. 1 is a block diagram for explaining an embodiment of a composite drawing apparatus according to the present invention.

FIG. 2 is a block diagram for explaining the composite drawing apparatus shown in FIG.

FIG. 3 shows an example of α performed in the combined drawing apparatus shown in FIG.
FIG. 9 is a diagram for explaining data generation processing.

FIG. 4 is an illustration of α performed in the composite drawing apparatus shown in FIG.
FIG. 9 is a diagram for explaining data generation processing.

FIG. 5 is a flowchart for explaining processing in a combined drawing data generation unit of the combined drawing apparatus shown in FIG. 1;

FIG. 6 is a diagram for describing α data generation processing in another embodiment of the composite drawing apparatus according to the present invention.

FIG. 7 shows an example of α executed by a combined drawing apparatus according to another embodiment.
It is a flowchart for demonstrating the data generation process.

FIG. 8 is a diagram for explaining a method of accessing a monochrome bitmap.

FIG. 9 is a diagram for explaining a method of accessing a monochrome bitmap.

FIG. 10 is a diagram for describing anti-aliasing.

FIG. 11 is a diagram illustrating an example of a function constituting an outline font.

FIG. 12 is a diagram illustrating an example of a function constituting an outline font.

[Explanation of symbols]

1 ... Synthetic drawing device, 11 ... Drawing data transfer buffer unit,
12: graphic accelerator, 13: VRAM, 1
4 VRAM, 15 VRAM, 21 digital video mixer, 21a D / A conversion circuit, 22 key signal controller, 100 composite drawing data generation unit, 101 C
PU, 102 ROM, 103 RAM, 104 VR
AM, 105 display controller, 109 system bus, 111, 112 I / O port, 31 input terminal, 32 A / D conversion circuit, 33 D / A conversion circuit, 34 D / A conversion circuit, 41, 42, 43 ... output terminal, 2 ... display, 3 ... keyboard, 4 ... mouse,
5. Switcher

Claims (12)

[Claims] 1. A color drawing image data for combining a display image with a color drawing image such as a character or a figure, and contour data used for combining the color drawing image with the display image. A method of generating composite drawing data, wherein the color drawing image is a black and white image, and for each drawing minimum unit area, an area ratio of a substantial drawing area for each drawing minimum unit area is obtained. Generating a composite drawing data based on the contour data. 2. A conversion table formed by associating a pattern of the substantial drawing area in the minimum drawing unit area with information for obtaining an area ratio corresponding to the pattern is provided. 2. The method according to claim 1, wherein the area ratio is obtained based on a pattern of the substantial drawing area in the minimum drawing unit area by referring to (a). 3. The black-and-white image, wherein the minimum drawing unit area of the black-and-white image is N of the minimum drawing unit area of the color drawing image.
(N is an integer) The drawing minimum unit is drawn in a unit area of N times the drawing minimum unit area in the expansion area based on the monochrome image drawn in the expansion area. 3. The method according to claim 1, wherein an area ratio of a real drawing area for each area is obtained. 4. A color drawing image data for combining a display image with a color drawing image such as a character or a graphic, and contour data used for combining the color drawing image with the display image. An apparatus for generating combined drawing data, wherein the color drawing image is a black-and-white image, and for each drawing minimum unit region, an area ratio of a substantial drawing region for each drawing minimum unit region is calculated. A composite drawing data generating apparatus, comprising: contour data calculating means for obtaining the contour data based on the contour data. 5. A conversion table formed by associating a pattern of the substantial drawing area in the minimum drawing unit area with information for obtaining an area ratio corresponding to the pattern. 5. The generation of the composite drawing data according to claim 4, wherein the area ratio is obtained based on a pattern of the substantial drawing region in the drawing minimum unit region by referring to the conversion table. 6. apparatus. 6. The black-and-white image, wherein the minimum drawing unit area of the black-and-white image is N of the minimum drawing unit area of the color drawing image.
(N is an integer) is provided with an enlargement drawing unit that draws in an enlargement area that is enlarged so as to be multiplied by a factor, and the outline data calculation unit uses the monochrome image drawn in the enlargement region to calculate the minimum drawing unit area in the enlargement area. 6. The synthetic drawing data generation apparatus according to claim 4, wherein an area ratio of a substantial drawing area for each of the drawing minimum unit areas is calculated for each of N times unit areas. 7. A drawing input means for inputting drawing information of a drawing image such as a character or a figure, and drawing image data generating means for generating color drawing image data in accordance with information from the drawing input unit. A drawing image display means for displaying the color drawing image generated by the drawing image data generation unit on a display screen; and the color drawing image as a black-and-white image, for each drawing minimum unit area, for each drawing minimum unit area. Calculating an area ratio of a substantial drawing area of the outline data, calculating contour data based on the area ratio, an input terminal of a video signal of a display image for synthesizing the drawn image, and Synthesizing means for synthesizing the color drawing image data with the video signal using the outline data calculated by the outline data calculating means; and an output terminal for outputting the synthesized image data Synthesis drawing apparatus comprising a. 8. A conversion table formed by associating a pattern of the substantial drawing area in the minimum drawing unit area with information for obtaining an area ratio corresponding to the pattern. 8. The composite drawing apparatus according to claim 7, wherein the area ratio is obtained based on a pattern of the substantial drawing area in the drawing minimum unit area by referring to the conversion table. 9. 9. The black-and-white image, wherein a minimum drawing unit area of the black-and-white image is N of a minimum drawing unit area of the color drawing image.
(N is an integer) an enlargement drawing unit that draws in an enlarged area that is enlarged by a factor of multiples, wherein the contour data calculation unit uses the black-and-white image drawn in the enlarged region to draw the minimum unit area in the enlarged region. 9. The composite drawing apparatus according to claim 7, wherein an area ratio of a substantial drawing area for each drawing minimum unit area is obtained for each N times unit area. 10. A drawing input means for inputting drawing information of a drawn image such as a character or a figure, and a drawn image data generating means for generating color drawn image data according to information from the drawing input unit. A drawing image display means for displaying the color drawing image generated by the drawing image data generation unit on a display screen; and the color drawing image as a black-and-white image, for each drawing minimum unit area, for each drawing minimum unit area. A contour data calculating means for calculating the area ratio of the substantial drawing area, and calculating the outline data based on the area ratio; an output terminal for outputting the color drawing image data; and an output terminal for outputting the outline data. A synthetic drawing apparatus comprising: 11. The outline data calculating means includes: a pattern of the substantial drawing area in the drawing minimum unit area;
A conversion table formed in association with information for obtaining an area ratio corresponding to the pattern, and by referring to the conversion table, based on the pattern of the substantial drawing area in the minimum drawing unit area. The composite drawing apparatus according to claim 10, wherein the area ratio is obtained. 12. An enlargement for drawing the black-and-white image in an enlarged area in which the minimum unit area for drawing the black-and-white image is N (N is an integer) times the minimum unit area for drawing the color drawing image. A drawing unit, wherein the outline data calculation unit calculates, based on the black-and-white image drawn in the enlarged region, a substantial drawing region for each of the drawing minimum unit regions in each of N times the minimum drawing unit region in the enlarged region. The composite drawing apparatus according to claim 10, wherein an area ratio of the composite drawing apparatus is obtained.