WO1999054847A1

WO1999054847A1 - Three-dimensional image processor

Info

Publication number: WO1999054847A1
Application number: PCT/JP1998/001771
Authority: WO
Inventors: Masahiro Shiraishi; Takatoshi Ueno; Kazunori Oniki
Original assignee: Hitachi, Ltd.; Hitachi Process Computer Engineering, Inc.
Priority date: 1998-04-17
Filing date: 1998-04-17
Publication date: 1999-10-28
Also published as: KR20010022919A

Abstract

A three-dimensional image processor for performing antialias processing including alpha-blend by using a little capacity of memory in a short processing time. The processor comprises a means for calculating an occupation pattern for every pixel, a means for storing occupation patterns, a means for storing the luminance of the pixel nearest to the viewer, a means for storing the depth to the nearest pixel from the viewer among pixels whose occupation patterns are 100 %, a means for calculating information to be stored in a memory from information on every pixel and information from the memory, a means for indicating the alpha-blending effectiveness of pixels of the image drawn, a means for storing the state of the alpha-blending effectiveness indicating means, a means for storing un-alpha-blending background colors, a means for storing un-alpha-blending background colors, and a means for selecting alpha-blending background colors. Since the antialias processing including alpha-blending can be performed by drawing an image in a one-pass way, the processing speed is high. Further since the memory capacity necessary for one pixel is less than that of conventional methods, the antialias processing can be realized at a low cost.

Description

Specification

3D image processing equipment

The present invention relates to a three-dimensional image processing apparatus that performs high-quality image display by anti-aliasing processing.

F¾, technique νΙϊ

When a graphic is displayed on a display device such as a raster-scan display, diagonal sides of the graphic are jagged. This occurs to determine whether to display the pixel with the luminance of the graphic or the luminance of the background outside the frame of the graphic, depending on whether or not the pixel constituting the display device is included in the graphic area. Is a phenomenon. To solve this phenomenon, a method has been used in which the brightness of the figure and the brightness of the background are blended based on how much the area of the figure is included for each pixel.

In Japanese Patent Application Laid-Open No. Hei 4-123086, the anti-aliasing process is performed by drawing the same figure a plurality of times with the coordinates shifted, synthesizing all luminances, dividing the luminance by the number of times of synthesizing at the time of display, and setting the display luminance. A technique for performing the above is disclosed. This method requires a processing time corresponding to the number of times of synthesis.

In addition, Japanese Patent Application Publication No. 5-507372 discloses a technique in which a figure is drawn in units of sub-pixels, and the luminance of the sub-pixels included in one pixel is mixed for display in displaying. ing.

In the conventional example, there is a problem that the cost is increased because many storage devices are required. In addition, the fact that the alpha blend processing is performed together with the anti-aliasing processing has not been considered in the above conventional example. An object of the present invention is to realize high-speed processing equivalent to the anti-aliasing processing of the precedent, including alpha blending processing, with a small number of storage devices. Disclosure of the invention

In the conventional example, a device for storing luminance and depth information is provided for each subpixel, but is not suitable for performing anti-aliasing processing with a small number of storage devices. Therefore, in the present invention, information such as brightness and depth is stored in units of one pixel, and in sub-pixel units, only whether or not they are included in the figure area to be drawn is stored as an occupation pattern. Yes. The anti-aliasing process is achieved by calculating the ratio between the region of the foreground graphic and the region of the background based on the occupation pattern, and blending the luminance of the foreground graphic and the luminance of the background with the ratio.

At this time, check whether the brightness of the background has already been alpha-blended, and check whether the brightness of the foreground figure is also alpha-blended, and if both have alpha-blended processing, In the anti-aliasing process, an unchained process including an alpha blend is achieved by blending with the brightness of the alpha blend process J instead of the brightness of the background.

When drawing a figure, the luminance of pixels constituting the figure, the depth of the drawing pixel, and the occupation pattern of the drawing pixel are calculated. First, a comparison is made between the depth of the total occupied depth storage device using the z-buffer having the same coordinates as the drawing pixel and the depth of the drawing pixel. If the depth of the drawing pixel is deeper, the drawing of that pixel is performed. To stop. Then, the luminance of the drawing pixel and the luminance of the same coordinate as the drawing pixel are determined by the ratio of the figure area between the occupation pattern of the drawing pixel and the occupation pattern of the occupation pattern storage device having the same coordinates as the drawing pixel. Storage device Of the frame buffer and the brightness of the frame buffer at the same coordinates as the drawing pixel, and store the result in the frame buffer again.

In this case, the brightness of the drawing pixel is the figure brightness before the alpha blending process, and the brightness of the brightness storage device at the same coordinates as the drawing pixel is not after the alpha blending process or the alpha blending process. The brightness of the drawing pixel, the brightness of the brightness storage device at the same coordinates as the drawing pixel, and the brightness of the frame buffer at the same coordinates as the drawing pixel are pre-rendered. When performing the anti-aliasing process, it is determined whether or not the drawing pixel has the alpha blending process, and whether the luminance stored in the luminance storage device has the alpha blending process is determined. If it is determined that the alpha blending process is performed, the alpha blending is performed using the brightness of the drawing pixel and the brightness of the background color before the alpha blending process. And performing a blending process for anti-aliasing using the result of the alpha blending process and the brightness of the brightness storage device. When it is determined that the drawing pixel has the alpha blending process, the fact is stored in the alpha blending process flag, and the background color before the alpha blending process is stored. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a block diagram showing the overall configuration of the hardware of the present embodiment.

FIG. 2 is a diagram showing a detailed block diagram of a rendering processor, and FIG. 3 is a diagram showing a configuration of an image memory.

FIG. 4 is a diagram illustrating selection of a process of a pixel information calculation unit.

FIG. 5 is a diagram showing a detailed flow of the alpha blend operation section. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, an embodiment of the present invention will be described with reference to FIGS.

FIG. 1 shows an overall block diagram of the hardware according to the present embodiment. The overall movement of this hardware is as follows: the CPU 100 that calculates the vertex coordinates of the figure to be drawn, the vertex brightness, and the vertex depth and issues them to the rendering processor 200, and the vertex coordinates sent from the CPU 100 Pixel information calculation unit 210 that calculates, as pixel information, the coordinates of the pixels constituting the figure, the brightness, the depth of the drawing pixel, and the occupation pattern of the drawing pixel, from the vertex luminance and the vertex depth, An alpha blending operation unit 220 that performs an operation for an alpha blend process from the pixel information thus obtained, and a pixel comparison operation unit that calculates a luminance for displaying from the processing result of the alpha blend operation unit 220 A rendering processor 200 comprising a pixel processor 230; an image memory 300 used for calculating the luminance and storing a luminance for display; and a frame buffer of the image memory 300. The CRT 500 comprises a display control means 400 for performing display based on the display luminance information stored in the buffer 310.

FIG. 3 shows a configuration diagram of the image memory 300. The image memory 300 has a frame buffer 310 that stores the luminance of each pixel displayed on the CRT 500, and the depth of the pixel that is the foremost occupation pattern until 100% of the sub-pixels are covered (total occupancy). A depth buffer), an occupancy pattern storage device 330 for storing the occupation pattern of the foremost pixel, a luminance storage device 340 for storing the luminance of the foremost pixel, Non-Alpha Blended Background Color Storage Device 350 that stores the depth of the foreground pixel, and Alpha Blend Pixel Flag Storage Device 3 6 that stores whether the alpha blending process has been performed on the foremost pixel. Consists of 0. When drawing a pixel that has been subjected to alpha blending, The outgoing / non-alpha blend background color storage device 350 stores not the depth of the foreground pixel but the background color (non-alpha blend background color) of the pixel before the alpha blend processing is performed.

The configuration of each memory pixel is as follows: the frame buffer 310 has 24 bits, the Z buffer 320 has 24 bits, the occupied pattern storage device 330 has 16 bits, and the luminance information storage device 3 40 is 24 bits, depth Z not alpha blended background color storage device 350 is 24 bits, and alpha-blended pixel flag storage device 360 is 1 bit. The frame buffer 310, the luminosity storage device 340, and the non-alpha blend background color storage device 350

It consists of a luminance R component of the 23rd to 16th bits, a G component of the 15th to 8th bits, and a B component of the 7th to 0th bits. Occupancy pattern storage

33 0 is a 16-bit occupation pattern of information of 16 sub-pixels included in one pixel, and is associated with bit number 25 in the sub-pixel. Is stored.

FIG. 2 shows the configuration of the rendering processor 200, and FIG. 5 shows the flow of processing in the alpha blend processing unit 225. As the operation of the hardware of this embodiment, first, the CPU 100 issues vertex coordinates, vertex depth, and vertex brightness of a figure (in this embodiment, a triangle which is a general polygon), It is passed to the pixel information calculation unit 10 of the rendering processor 200. The pixel information calculation unit 210 interpolates the X values of the pixels between the vertices in units of 14 pixels in the Y coordinate direction based on the received information on the vertices of the figure, and interpolates each pixel constituting the figure. Is expanded into 4x4 sub-pixels, and the figure area is calculated in sub-pixel units. Next, the center point of the subpixel is set to '0' for the subpixel included in the figure, '1' otherwise, and the value for each subpixel in one pixel is calculated. This is passed to the alpha blend operation unit 220 as a 16-bit occupation pattern. At the same time, the brightness and the depth of the pixel having the same coordinates as the pixel developed into the sub-pixel are transferred to the alpha prend calculation unit 220. Hereinafter, unless otherwise specified, the read information of each memory in the image memory 300 will be described as information of a memory having the same coordinates as a pixel to be drawn.

As shown in FIG. 5, the alpha blend operation unit 220 determines whether or not to perform alpha blend processing on the pixel to be drawn.

(2 2 4), the result of this determination is referred to as A3. When determining whether or not to perform the alpha blending process, the CPU 100 determines whether the alpha blending process is enabled (enabled) or disabled (not enabled). (Not shown) is set and checked by checking this register.

When the alpha blending process is not performed, the pixel I to be rendered is used as the rendering pixel luminance IA output from the alpha blending calculation unit 220, and the luminance I from the pixel information calculation unit 210 is used as it is. Hand over (1001). When the alpha blending process is performed on the pixel to be rendered, whether or not the most recently rendered image has been rendered after the alpha blending process has been performed is determined by the alpha-blended pixel flag storage device 360. Judgment is made based on the content AB (2 2 3), and this judgment result is set as A2. Alpha blended pixel flag storage device 360 0 When AB power is '0', it is judged that the foremost pixel that has already been drawn has been drawn without performing alpha blending. In the alpha blending process for the pixels to be rendered, the R, G, and B values of the already rendered colors stored in the frame buffer 310 are used as the background color for the alpha blending process. Then, the alpha blend with the pixel to be drawn is calculated. So After that, the calculated alpha blend result is output as the drawing pixel luminance I 出力 output from the alpha blend operation unit 220 (1002).

On the other hand, when the content of the alpha blended pixel flag storage device 360 is '1', the foremost pixel that has already been rendered is determined to have been rendered after performing alpha blend processing, and rendered. It is necessary to change the alpha blend processing method depending on whether the pixel to be processed is the edge of the figure area (polygon). This is because the anti-aliasing process is not performed if the pixel to be drawn is not an edge, so the color already drawn as the background color of the alpha blend (frame buffer 310 Information) can be used.

However, if the pixel to be drawn is an edge, anti-aliasing may be performed. Normally, for a three-dimensional object, when the object surface is divided into fine polygons and the alpha blend is performed to sequentially draw these adjacent polygons, the edge of the polygon is replaced by the previous polygon. At the time of drawing, alpha blending is also performed for the foreground pixel that has already been drawn. Therefore, if the already drawn color is used as the background color of the alpha blend of the pixel of the edge to be drawn, the result of performing alpha blending twice for the pixel of the same coordinates will result. For this reason, the background color of the alpha blend of the pixel to be drawn is already drawn: δ must also use the background color of the previous pixel before the alpha blend processing is performed.

Therefore, if the alpha blending process has been performed on the foremost pixel that has already been drawn, whether or not the pixel to be drawn is an edge is determined by all the bit forces of the pixel occupation pattern Ρ. Judgment is made based on whether it is '0' (2 2 1), and this judgment result is set as A1. g

If the total bit power of the occupation pattern of the pixel to be drawn is “0”, all sub-pixels are graphic regions, so it can be determined that they are not edges of the graphic region (polygon). Therefore, since the anti-aliasing processing is not performed in the subsequent processing in the pixel comparison operation unit 230, the frame buffer 3 shown as the background color of the alpha blending processing for the pixels to be drawn from now on Use 10 colors (1002).

However, if the total bit strength of the pixel occupation pattern P is not '0' (any bit has '1'), it indicates that this pixel is the edge of the figure area (polygon). I have. Since the result of the alpha blending process is drawn on the foreground pixel that has already been drawn, the non-alpha blend is used as the background color of the alpha blend of the pixel to be drawn, as described above. The background colors R, G, and B stored in the background color storage device 350 before the alpha blending process is performed on the foremost pixel that has already been drawn are used (1003). After that, the calculated alpha blend result is output as the drawing pixel luminance IA output from the alpha blend operation unit 220 (1002).

Next, the processing in the screen comparison performing section 230 will be described with reference to FIG. 2 and FIG.

The pixel comparison calculation unit 230 compares the depth Z of the drawing pixel calculated by the pixel information calculation unit 210 with the depth information ZB of the Z buffer 320 and sets the comparison result to C 0 .

Next, in order to determine whether or not the foremost pixel that has already been rendered has been rendered after performing the alpha blending process, the content AB of the alpha blended pixel flag storage device 360 is set to 1 when the content AB is set to '1'. (2 2 3) A2. When there is no alpha blend (AB b '0,), Next, in order to determine whether or not to perform alpha blending on the rendering pixel, it is determined whether or not the alpha blending flag of the rendering image is “1” (2 24). And

Next, a logical OR is performed on a bit-by-bit basis with the occupation pattern P of the drawing pixel and the occupation pattern PB of the occupation pattern storage device 330, and this is defined as C1.

If P and PB are occupied patterns of pixels adjacent to each other, the result of the bitwise OR of these two occupied patterns is all bit power '1'. On the other hand, when the occupation patterns of the pixels overlap each other, the result of the bitwise OR of these two occupation patterns indicates that the bit of the overlapped portion is '0'. That is, by performing a bit-wise logical OR of the occupation pattern P of the drawing pixel and the occupation pattern PB of the occupation pattern storage device 330, it is determined whether or not the drawing pixel overlaps the figure area portion of the foremost pixel. Can be determined.

Also, the result of comparing the depth Z of the drawing pixel with the depth ZB of the depth storage device 350 is defined as C 3, and the occupation pattern P of the drawing pixel and the occupation pattern PB of the occupation pattern storage device 330 are defined as C 3. Then, it is determined whether or not the result of this bit-wise logical AND of all 16 bits becomes “0”, and this is defined as C 4. If this C4 is true, that is, the result of the bitwise AND operation, and all the 16 bits become “0”, the occupation pattern P of the drawing pixel and the occupation pattern PB of the occupation pattern storage device 330 will be 2 With one occupation pattern, all subpixels at the drawing position are covered.

Based on the above determination results A2, A3, C0, C1, C3, C4, and C5 signals, the pixel comparison operation unit 236 performs processing 1 according to the table shown in FIG. Perform steps 4 to 24.

First, if 〇 0 is 0, the pixel to be drawn is deeper and the viewpoint Since the drawing pixel viewed from the direction is hidden by the preceding pixel and cannot be seen, there is no need to update the information in the frame buffer 310, so the drawing of the pixel is stopped (process 24).

Also, when C 0 is 1 and the drawing pixel is nearer or equal, if A 2 and A 3 are both 0, that is, neither the drawing pixel nor the previously drawn pixel has been subjected to alpha blending. If C3 is true (the drawing pixel is at the foreground or equal), and if the result of C4 is true, the processing 14 (the following processing A, C, E, F, G) is performed. If C4 is false, perform processing 15 (processing A, C, E, and F below). On the other hand, if C3 is false, processing 16 (processing B below) is performed regardless of the result of C4.

Also, if A 3 is true and there is an alpha blending process on the pixel to be drawn, whereas A 2 is false and the foreground pixel already drawn has no alpha blend, C 3 is true (If the pixel to be drawn is near or equal to this), if C4 is true, perform processing 1 以下 (the following processing H, I, E, F, G), and if C4 is false If all 16 bits of the bit unit logic between the occupation pattern P of the drawing pixel and the occupation pattern storage device 330 are not set to '0', the processing 18 (the following processing) G, I, I, E, F).

On the other hand, if C3 is false and the pixel to be drawn is deep, processing 19 (processing J below) is performed regardless of the results of C1 and C4.

And if A2 is true and alpha blending has been performed on the foremost pixel that has already been drawn, then A3 will be false and alpha blending will not be performed on the pixel to be drawn. For example, processing 20 (the following processing A, C, E, and F) is performed regardless of the results of C1, C3, and C4. In this case, if it is determined that there is no alpha blending, the depth of the pixel Non-judgment force This is because the foremost pixel that has already been drawn has an alpha blend, and the depth for the drawn pixel is not stored in the case of alpha blending. The reason can be explained by the following example. Consider the example of drawing a transparent glass cup. Since the cup is transparent, it will be drawn with alpha blend. At this time, if the depth is written to the Z buffer 310 etc. for each pixel constituting the cup and the drawing process is performed while judging the depth, there is a problem in the case where the cup is drawn from the back to the front. However, in the case where the glass is drawn from the front pixel to the back, the back glass will not be drawn, so the clear glass should be visible, but there is a problem that it will not be visible.

Therefore, when performing alpha blending, since the drawing is performed regardless of the depth, the depth of the pixel is not memorized, but always overwritten (the pixel to be drawn is always closer to the front). Therefore, the result of the depth comparison processing of C3 is meaningless, and is always overwritten.If the previous pixel that has already been drawn has been alpha-blended and A2 is true, the occupied pattern Since there is no depth information for determining that the C is 100%, the determination of C4 is meaningless, and the determination of C4 is unnecessary.

If A2 is true and alpha rendering has been performed on the foremost pixel that has already been rendered, then if there is alpha blending for the pixel to be rendered (A3 is true), the most rendered pixel will be The result of C1 indicates whether the occupation pattern of the pixel in front and the pixel to be drawn overlap each other as a result of C1 (by the bitwise logical OR of the occupation pattern of the drawing pixel and the occupation pattern of the occupation pattern storage device 330, All six bits are determined by the force '1'.

When C1 is true and all 16 bits are determined to be '1', the two occupied ₂

Since the turns do not overlap, refer to the judgment result of C4.If C4 is true, the two occupied patterns both have alpha blending and cover 100% of the subpixels. Then, the two occupation patterns are combined, and the pixel is regarded as one occupation pattern with an alpha blend that covers 100% of the pixel, and processing 21 (the following processing H, K, D, and F) is performed. On the other hand, if C4 is false, the background is visible in any of the sub-pixels, and thus processing 22 (processing H, D, and F below) is performed.

If C1 is false and it is determined that the two occupation patterns overlap, processing 23 (processing H, I, E, and F below) is performed. At this time, since the foreground pixel already drawn has an alpha blend, the determination of C4 is unnecessary as in the case of performing the processing 20.

In the above processing, each memory in the image memory 300 that has not been updated stores the information before drawing the drawing pixel as it is.

Hereinafter, the processings A, B, C, D, E, F, G, H, I, J, and K will be described.

Processing A calculates the luminance to be stored in the frame buffer 310 when the depth Z of the drawing image is closer or equal to the depth ZB 3 23 read from the depth storage device 350. This is the processing to be performed.

In process A, the occupation pattern (drawing area) of the drawing pixel that comes to the foreground as viewed from the viewpoint direction and the occupation pattern storage device 330 already stored in the occupation pattern storage device 330 corresponding to the second pixel from the front side The luminance and luminance of the drawing pixel for each RGB component according to the ratio of the foreground occupation pattern (drawing area) PB that has been drawn and the sub-pixels of the drawing pixels that are not covered by these two occupation patterns corresponding to the background. Weighting and mixing are performed with the ratio of subpixels that occupy the luminance of the storage device and the luminance of the frame buffer. In this case, the occupation of the drawing pixel 5 ₁ g / JP9 / 1

Since the pattern is the foreground when viewed from the viewpoint direction, the occupation pattern of the drawing pixel P: The occupation pattern of the drawing pixel P is not covered by PB: The ratio of subpixels not covered by P and PB is mixed. And newly stored in the frame buffer 310.

The ratio of the pixels already drawn corresponding to the background is the part that is not included in the two occupation patterns of the drawing pixels corresponding to the second Ζ coordinate from the front and the front, and the brightness is not known. Approximate by the luminance read from buffer 310.

Processing 、 is based on the assumption that the pixel to be rendered is located second from the front among the pixels that have been rendered before, and from the depth 3 24 read from the depth storage device 350 The pixel depth 85 is a process for calculating the luminance to be stored in the frame buffer 310 when the depth is 85.

In the processing Β, unlike the processing Α, the occupation pattern PB stored in the occupation pattern storage device 330 is located at the foreground when viewed from the viewpoint direction. Occupation pattern stored in device 330 Occupation pattern of drawing image not covered by PB-P: Occupied pattern storage device PB stored in device 330 PB: Subpixel not covered by P, PB Is the ratio of

In process C, if the depth of the drawing pixel is equal to or shorter than the depth of the pixel drawn so far, the depth Z of the drawing pixel is stored in the depth Z unalphabed background color storage device 350. Store and update the depth of the foreground pixel.

The processing D is performed by using the occupation pattern P of the drawing pixel and the occupation pattern of the foremost pixel that has been previously drawn and stored in the occupation pattern storage device 330. When it is determined that PB and PB are continuous, it is assumed that the two pixels are continuous, and these two occupation patterns are combined by ANDing them to form a mutual graphic area (the area of '0'). ) Are combined to update the content PB of the occupation pattern storage device 330 as one occupation pattern.

The processing E is performed when the drawing pixel is equal to or shorter than the depth of the foremost pixel so far, and the occupied pattern of the foremost pixel stored in the occupied pattern storage device 330 is This is a process for updating the pattern with the pattern occupied by the drawing pixel.

The processing F is to calculate the luminance of the nearest pixel stored so far in the luminance storage device 340 when the depth of the drawing pixel is closer to or equal to the depth of the depth storage device 350. This is a process of updating with the brightness of the drawing pixel. Processing G is that if two pixels, the drawing pixel and the foremost pixel that has been previously drawn, cover 100% of the pixel, the G that has been drawn so far, that is, Even if there is a pixel to be drawn further behind the two pixels of the foremost pixel that has been drawn, since that pixel is not visible from the viewpoint direction, the depth of the foremost pixel that has been previously drawn is The occupation pattern of 100% is the process of writing the depth of the image in front into the Z buffer 320 that performs ILU.

Processing H is a luminance for storing in the frame buffer 310 when the depth Z of the drawing pixel is closer to or equal to (C 3 = l) than the depth ZB read from the depth storage device 350. Unlike the processing A, the brightness of the sub-pixel not covered by the foreground and the second occupied pattern as the background color is not the value of the frame buffer, but the value of the pixel Background color used for process M or process N) in alpha blend processing section 2 25 in 0, that is, frame buffer 13. The luminance read from 310 or the non-alpha blended background storage.

In process I, when the pixel to be rendered performs an alpha blending process (A 3 = l), the foreground pixel previously rendered is already alpha-blended (A 2 = 0) and overlaps the occupied pattern of both. When there is (C 1 = 0), or when the drawing pixel is also before S (C 3 = 1) before the previous pixel, the background color of the non-alpha blend of the pixel to be drawn (that is, This is a process of storing the luminance of the frame buffer 310 in the non-alpha blend background color storage device 350.

The processing J is a processing performed on the assumption that the drawing pixel is located second from the front among the pixels that previously performed the drawing, and the depth ZB read out from the depth storage device 350. This is a process of calculating the luminance to be stored in the frame buffer 310 when the depth Z of the drawing pixel is deeper than 3 2 4.

In the processing J, instead of the processing B, the background color used by the alpha blend processing unit 225 in the alpha blend calculation unit 220 is used instead of the frame buffer value as the background color. The difference from the processing H is that the pixel to be drawn is regarded as the second from the front. Therefore, Z buffer (because depth is not considered in alpha blending) and PB, IB, and ZB are not updated.

In process K, the pixel to be rendered and the foremost pixel that has been previously rendered both have an alpha blend (A 2 = 1, A 3 = 1), and their occupancy patterns do not overlap (C l = l), and the pixels are 100% covered by the occupation pattern of both (C4 = 1), that is, if the subpixels covered by P and PB are 100%, the pixels to be drawn When, ι

Since the background other than the two pixels from the foreground line that has been drawn previously is not visible, it is the color to be written to the frame buffer 310, not the unalphabed background color of the pixel to be drawn originally This is a process of writing the drawing image and the display color after anti-aliasing processing of the foremost pixel that has been previously drawn to the non-alpha-preset background color storage device 350.

The anti-aliasing process can be performed by performing the above processing for all the pixels constituting the figure.

In the present embodiment, in order to reduce the capacity of the storage device, the depth storage device and the non-alpha blend back-color storage device are shared (350). This is because alpha blend processing can be realized without memorizing the depth of the pixel as described above. However, there is also a method of storing depth when performing alpha blend processing in 3D image processing. In such cases, depth and non-alpha blend background colors cannot be shared using a single storage device. In such a case, a depth storage device that stores only the depth is stored in the depth blending device, and a non-alpha blend background that stores only the depth of the unblended background color is stored.惊装 [I can solve it by dividing into two. In this case, in order to determine the background color of the alpha blend in the alpha blend operation unit 220, means for selecting the frame buffer 310 or a non-alpha blend background color storage device is required. Industrial applicability

In the present invention, anti-aliasing including alpha blending can be performed at a high speed because it can be performed by one drawing, and luminance is calculated by using the foreground occupation pattern held in units of one pixel. Less Η

It can be realized with a small memory.

Claims

The scope of the claims

1. A pattern (hereafter referred to as “sub-pixel”) indicating whether or not a small pixel (hereinafter referred to as “sub-pixel”) obtained by further dividing the pixel into a plurality of pixels is included in the area of the figure. An occupancy pattern),

Pattern storage means for storing the occupied pattern of the foremost pixel.

For each pixel of the figure,

A frame buffer for storing a result of performing an alpha blend process between the luminance of the foreground figure and the luminance of the background when performing anti-aliasing processing;

Means for storing luminance information of the foremost pixel before performing the alpha blending process;

When the rendering pixel has an alpha blend process, the rendering pixel has a non-alpha blend background color unit that stores a non-alpha blend background color of the pixel. Alpha blend background Store in color storage

A three-dimensional image processing device, characterized in that:

2. In Claim 1,

It has a flag indicating that alpha blend processing is to be performed on the drawing pixel, and an alpha blend processing storage means for storing whether or not alpha rendering processing has been performed on the foremost pixel for each pixel. Features a three-dimensional image processing device.

3. In Claim 2,

The state stored in the alpha blend processing storage means, An occupancy pattern of a search to be executed for the alpha blending process, which is generated by the butterfly research means, and

According to the state of the preceding pixel occupation pattern, the ■ ¾ stored by the δ means

The background color of the pixel for which the alpha blend process is performed is

Select whether to use the contents of the non-alpha-preview background color means or the contents of the frame buffer, and perform alpha blend processing and anti-aliasing processing using the selected background color.

A three-dimensional image processing device, characterized in that: