JP2001109896A - Edge drawing method and image processor using same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an edge drawing method which makes easier to recognize the shape of a figure on a display screen or reduces the jaggedness of an edge part of the figure when an object group having three-dimensional coordinates is displayed as a digital image on a two-dimensional display screen, and an image processor which uses the method. SOLUTION: For a digital image of a display object, data on each pixel and pixels around it are used to decide whether or not the pixel is positioned at the edge part of the digital image and a specific process is performed only for the pixels which are so decided that they are positioned at the edge part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an edge drawing method for displaying a graphic as a digital image on a two-dimensional display screen and an image processing apparatus using the method.

[0002]

2. Description of the Related Art In recent years, in an image processing apparatus using computer graphics technology such as a game apparatus, it has been desired to improve the quality of an image displayed on a two-dimensional screen such as a CRT and to make it look good. I have.

Such an image processing apparatus considers a figure in a three-dimensional space to be displayed, that is, an object having three-dimensional coordinates, as an accumulation of polygons (polygon planes), and attribute data (hereinafter polygon data) of the polygons. ) To generate a final two-dimensional image.
This two-dimensional image is a so-called digital image expressed in units of pixels, and is expressed on a display screen such as a display. The polygon data is a data group including information such as coordinates of each vertex of the polygon and color data.

FIG. 20 is a diagram showing a rough configuration of a general image processing apparatus. The CPU 1 controls the overall functions of the image processing apparatus, and sends polygon data of an object to be represented on a display screen to a geometry unit 2 according to a program. The geometry unit 2 is a unit that performs processing such as coordinate transformation and perspective transformation, and the transmitted polygon data is converted into two-dimensional data corresponding to the display screen.

Next, the rendering unit 3 performs various processes based on the polygon data converted from the two-dimensional data sent from the geometry unit 2 to obtain the color of each pixel (ie, RGB) displayed on the display screen. Is finally determined. Here, processing to interpolate the color of each pixel from the vertex coordinates and color data included in the polygon data, hidden surface processing to determine the vertical relationship in the depth direction of each polygon on the display screen, shading to express the effect of light , Or a process of texture mapping that expresses a pattern on the surface of the display target or the like, and a process for visualizing the object as the display target more realistically. Finally, the final color (that is, RGB luminance) of each pixel determined by the rendering unit 3 is written to the frame buffer 4, and the information is displayed on the display screen.

[0006] In a general game device or the like, an object to be displayed is visualized by the above-described device to generate a screen having virtual reality.

[0007]

However, depending on the screen to be displayed, the colors and shapes of the main display objects (objects and polygons constituting the objects) are similar to the background image, so that the viewer of the screen may not be able to see the screen. In some cases, it is difficult to recognize the main display target. In a game device or the like, it is a major operational problem that the operation target on the screen becomes difficult to see.

Further, an image processing apparatus that expresses a display object by a digital image which is a sequence of pixels inherently has a problem of aliasing, and if processing for that is not performed, the display object cannot be displayed. There is a problem that jaggedness appears at an edge portion and a realistic expression is impaired.

Accordingly, an object of the present invention is to make it easier to recognize the shape of a figure on a display screen when displaying a group of objects having three-dimensional coordinates as a digital image on a two-dimensional display screen. It is another object of the present invention to provide an edge drawing method and an image processing apparatus using the same, which can reduce jaggedness in an edge portion of the figure.

[0010]

In order to achieve the above object, one aspect of the present invention is to provide a digital image of a display object for each pixel by using data of the pixel and surrounding pixels. It is determined whether or not the pixel is located at the edge of the digital image, and specific processing is performed only on the pixel determined to be located at the edge. Therefore, according to the present invention, it is possible to easily recognize the display target on the display screen, or to reduce the jagged feeling at the edge of the display target.

According to another aspect of the present invention, there is provided an image processing apparatus for drawing an object group having three-dimensional coordinates on a two-dimensional display screen including a row of pixels. In the edge drawing method for a drawing target graphic to be drawn, when drawing one drawing target graphic on the display screen, the drawing target graphic is included in a region of a predetermined size including the one drawing target graphic in the display screen. A first step of determining, for each pixel, whether or not the pixel is present at an edge of the one drawing target graphic; and The method is characterized by including a second step of performing a predetermined process only on the determined pixel.

Further, in the above-mentioned invention, in a preferred aspect, the determination in the first step is such that the pixel is present in the one drawing target graphic and is located at a predetermined position located around the pixel. When one or more pixels out of the number of pixels do not exist in the one drawing target graphic, it is determined that the pixels exist in the edge portion.

Further, in the above-mentioned invention, another aspect is as follows.
The one drawing target graphic is one polygon, and the predetermined process in the second step sets a drawing color of a pixel determined to be present in the edge portion as a color expressing the outline of the polygon. Processing.

Further, in the above invention, another aspect is as follows.
The one drawing target graphic is a graphic made up of a set of polygons representing one object, and the predetermined processing in the second step is to change a drawing color of a pixel determined to be present in the edge portion, It is characterized in that the processing is a color rendering process that represents the outline of the object.

Further, in the above invention, another aspect is as follows.
The predetermined process in the second step is to change the drawing color of the pixel determined to be present in the edge portion with the color of the one drawing target graphic and the pixel before drawing the one drawing target graphic. It is characterized by a blending process of blending and determining the colors that have been possessed.

[0016] Further, in the above invention, another aspect is as follows.
The color blending in the blending process is performed at a rate corresponding to the number of pixels existing in the one drawing target graphic out of a predetermined number of pixels located around the pixel.

According to another aspect of the present invention, there is provided an image processing apparatus for rendering an object group having three-dimensional coordinates on a two-dimensional display screen.
An image processing apparatus that writes a drawing target graphic into a frame buffer as a digital image composed of pixel-based data constituting the display screen based on a drawing command from A memory for temporarily storing color data of all pixels included in a region of a predetermined size including the digital image, wherein each time the drawing command for one drawing target graphic is received, A temporary storage memory in which pixel color data is initialized, and the one drawing target graphic given together with the drawing instruction after the temporary storage memory is initialized based on a drawing instruction for the one drawing target graphic A digital image of the one drawing target figure from the data of A writing unit for writing the color data into the temporary storage memory; and, for all pixels whose data is stored in the temporary storage memory after writing by the drawing unit, a target pixel from the temporary storage memory for each pixel. Reading means for reading out the color data and the color data of a predetermined number of peripheral pixels located around the target pixel; and the drawing means generates the target pixel from the color data read by the reading means. It is determined whether or not it exists at the edge of the digital image, and when it is determined that it exists at the edge,
An edge portion detection processing means for changing the color data of the target pixel by a predetermined process and leaving the color data of the target pixel as it is when it is not determined that the color data of the target pixel exists in the edge portion; An image processing apparatus comprising: a writing unit that writes a digital image of the one drawing target graphic into the frame buffer based on the color data of the target pixel after the processing in.

In a preferred aspect of the present invention, the initialization of the temporary storage memory is performed by making color data of all pixels stored in the temporary storage memory transparent. The determination as to whether or not the target pixel exists in the edge portion by the processing means determines whether the color data of the target pixel is not transparent and the color data of one or more of the peripheral pixels is transparent. The determination is performed by determining that the pixel exists at the edge portion.

Further objects and features of the present invention will become apparent from the embodiments of the present invention described below.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. However, such embodiments do not limit the technical scope of the present invention.
In the drawings, the same or similar components are denoted by the same reference numerals or reference symbols.

FIG. 1 is a block diagram of an image processing apparatus according to a first embodiment of the present invention. The first embodiment is
An edge portion is detected for each polygon constituting an object, and a contour is added to the detected edge portion so that the polygon can be easily recognized on a display screen. 2A and 2B are diagrams illustrating an example of adding a contour to a polygon. FIG. 2A illustrates a state without a contour, and FIG. 2B illustrates a state where a contour is added. By displaying the polygon in the state shown in (b), the shape of the polygon can be easily recognized while being distinguished from other shapes.

As shown in FIG. 1, the image processing apparatus according to the first embodiment has a rendering unit 3
1, a temporary storage memory 32, a reading unit 33, an edge detection processing unit 34, and a writing unit 35. The configuration of the entire image processing apparatus is the same as the conventional apparatus described with reference to FIG. In the rendering unit 3, parts for performing hidden surface processing, shading processing, texture mapping processing, and the like are arranged as necessary as in the conventional apparatus, but illustration of these parts is omitted. ing.

FIG. 3 is a diagram showing a flow of processing in the rendering unit of the image processing apparatus according to the present embodiment.
Here, the processing contents for one polygon are described. Hereinafter, based on FIG. 1 and FIG. 3, the functions of the respective units from the drawing unit 31 to the writing unit 35, which are features of the image processing apparatus, and the processing procedure will be specifically described.

First, a command to draw a polygon is given from the CPU 1, and one piece of polygon data converted into two-dimensional coordinates on the display screen is sent from the geometry unit 2 to the drawing unit 31 (step S1 in FIG. 3). . The polygon data to be sent includes the two-dimensional coordinates of the vertices, the color data of the polygon, and the like, and further adds control information as to whether or not to add a contour. FIG. 4 is a diagram conceptually illustrating the polygon data sent to the drawing unit 31. In the example shown in the figure, the polygon data of the polygon P has three vertex coordinates (X ₁ ,
Y _1), shows that it is composed of _{(X 2, Y 2),} (X 3, Y 3), color data, and control information of the contour added.

The drawing unit 31 draws a polygon image, which is a digital image of the polygon (an image composed of a series of pixels), in the temporary storage memory 32 based on the sent polygon data. In addition, the temporary storage memory 32
Is a storage memory for temporarily storing the polygon image, and its size is arbitrary, but is the same size as the frame buffer 4 here. When the above-described polygon drawing command is given, first, the temporary storage memory 32 is filled with transparent pixels (step S2 in FIG. 3).

Next, based on the vertex coordinates of the given polygon data, the drawing unit 31 stores the temporary storage memory 32
Above, the pixels in the range where the polygon is displayed are obtained, and those pixels are filled with the color data of the given polygon. That is, a polygon image is drawn on the temporary storage memory 32 (step S3 in FIG. 3). FIG.
2 shows a state in which the polygon P illustrated in FIG. In the figure, P ′ is a polygon image of the polygon P, and the pixels constituting the polygon image are filled with the color of the color data. On the other hand, the pixels other than the polygon are transparent.

When the drawing of the polygon image is completed, next,
The reading unit 33 reads out the pixel-by-pixel color data stored in the temporary storage memory 32 one by one and sequentially passes the color data to the edge detection processing unit 34 (Step S4 in FIG. 3). At this time, not only the pixels in the polygon image are read out, but all the pixels in the temporary storage memory 32 are sequentially read out. Further, for the edge detection determination by the edge detection processing unit 34, the color data of eight pixels located around one read pixel is also read simultaneously (step S5 in FIG. 3).

Next, the edge detection processing section 34 is a section for detecting an edge portion of the polygon image and performing processing for adding a contour to the edge portion. Here, a determination is made sequentially for one pixel read by the reading unit 33 according to the contouring condition. The contouring condition is a condition for determining whether or not the target pixel is located at an edge of the polygon and is a part of the contour to be added to the polygon. Specifically, the determination is made according to the following equation (1) using the color data of the eight peripheral pixels (step S6 in FIG. 3). Satisfaction of contouring condition = The pixel is a part of polygon (having polygon color data), transparent pixels exist in eight surrounding pixels, and the control information of contour addition of polygon data is "added" (1)

FIG. 6 is a diagram exemplifying the determination based on the contouring condition. (A), (B) and (C) in FIG.
5 shows the state of pixels A, B, and C and eight pixels around them (a part, b part, and c part in FIG. 5). As for the pixel A, as shown in (A), the contouring condition is satisfied because the pixel A itself is a part of the polygon image P ′ and the surrounding pixels include transparent pixels. pixel
Regarding B, although it is itself a part of the polygon image P ′, since all the peripheral pixels are also present in the polygon and do not include transparent pixels, the contouring condition is not satisfied. Also, regarding pixel C, itself is a polygon image P '
, The contouring condition is not satisfied. In this example, as shown in FIG. 4, it is assumed that the control information for adding the contour of the target polygon P is “addition”.

FIG. 7 shows an example of the polygon P shown in FIG. 4, in which all pixels are determined based on the contouring condition. In the figure, the pixels indicated by ● are the pixels satisfying the contouring condition, and are the portions to be the contours to be added to the polygon P. In this device,
Although eight peripheral pixels are used in the determination based on the contouring condition, a device using different numbers of peripheral pixels may be used.

As described above, when the pixel is determined and the contouring condition is satisfied, the edge detection processing unit 34 converts the color data of the pixel to the color of the contour to be added to the polygon. It is changed (step S7 in FIG. 3). On the other hand, when the condition is not satisfied, the color data is left as it is.

Next, the color data of the pixel processed by the edge detection processing unit 34 is written into the frame buffer 4 by the writing unit 35. At this time, if the pixel to be written is transparent, that is, if the pixel is outside the polygon, writing to the frame buffer 4 is not performed. Therefore, only pixels forming a polygon image having the color or outline color given as polygon data are written (FIG. 3).
Steps S8 and S9). This eliminates the need to update the entire frame buffer 4 every time one polygon is to be displayed, and allows a plurality of polygons to be simultaneously displayed on one display screen.

The processing (steps S4 to S9 in FIG. 3) in the reading section 33, the edge detection processing section 34, and the writing section 35 described above is performed on all the pixels in the temporary storage memory 32 (FIG. 3). Step S10), the processing for one polygon that has received the drawing instruction is completed. As a result, the polygon has a contour added to its edge,
Displayed on the display screen. FIG. 8 shows the polygon shown in FIG.
This shows a state where the processing for P has been completed and the data has been written to the frame buffer 4. As described above, the pixels located at the edge portions of the polygon are displayed in the outline color as a result of the outline formation condition being satisfied, and the outline is added to the polygon as a whole.

Normally, since a plurality of polygons are displayed on one display screen, the above-described processing based on FIG. 3 is performed on all the polygons to complete one screen. FIG. 9 shows an example in which a plurality of polygons are displayed on the display screen. FIG. 9A shows a case where a normal expression is added without adding an outline, and FIG. This shows a case where a contour is added. As is clear from the figure, by adding the contour, it is possible to easily recognize the overlapping state and the positional relationship between the polygons.

FIG. 10 shows a display example when an outline is added only to a specific polygon. The polygon to which the contour is added can easily recognize its shape and position as compared with other polygons, and is effective for a polygon that needs to be watched particularly, such as an operation target in a game device.

As described above, by using the image processing apparatus according to the first embodiment to add a contour to the edge portion of the polygon to be displayed, the color and pattern are similar to those of the adjacent polygon or background image. There is an effect that the target polygon can be easily recognized even when the recognition is difficult. In addition, by providing control information for adding a contour to polygon data, it is possible to add a contour only to a specific polygon.

Next, a second embodiment to which the present invention is applied will be described. In the first embodiment described above, a contour is added for each polygon. In the second embodiment, a contour is added to an edge portion of an object composed of a plurality of polygons. FIG. 11 shows an example in which two objects are displayed overlapping each other. FIG. 11C is a top view showing the actual shapes and positional relationships of the two objects. (A) and (b) show a normal display example without a contour and a display example in which a contour is added to the object in front, respectively. In the case of (a), the existence of two objects and the shape of the object are unclear, but in (b), it is clear that they are easily recognized.

The configuration of the image processing apparatus according to the second embodiment is the same as the configuration of the apparatus according to the first embodiment shown in FIG. The processing procedure is the same as that of the first embodiment. In the processing flow shown in FIG. 3, “polygon data” is changed to “object data”.
"Polygon image" is replaced with "object image". Hereinafter, the processing contents of the image processing apparatus according to the second embodiment will be described, focusing on the differences from the first embodiment.

As in the first embodiment, first, a drawing command from the CPU 1 is given, but not a drawing command for a polygon alone, but a drawing command for an object consisting of a set of polygons. (Step S1 in FIG. 3).

The object data is vertex coordinates and color data of each polygon constituting the object, and non-contour control information indicating whether or not a contour is added to the object. FIG. 12 is a diagram conceptually illustrating the object data sent to the drawing unit 31. In the example shown in the figure, object data of an object O composed of _three polygons P ₁ , P ₂ , and P _{3 is} composed of three sets of polygon data (vertex coordinates and color data) and control information for adding a contour. It indicates that

Next, as in the case of the first embodiment, the temporary storage memory 32 is initialized with transparent pixels (step S2 in FIG. 3), and the drawing unit 31 places thereon the digital image of the object to be processed. Is drawn (step S3 in FIG. 3).

The drawing is performed by drawing all the polygons constituting the object. Temporary storage memory 32
When the object image is drawn, the reading unit 33 reads out color data one by one for all the pixels in the temporary storage memory 32 (step S in FIG. 3).
4) In the edge detection processing unit 34, the determination is sequentially performed on the read pixels based on the contouring condition. At this time, color data is also read for eight pixels around the read pixel (step in FIG. 3).
S5). This part is the same as the processing of the first embodiment. The basic concept of the contouring condition used here is the same as that shown in the above equation (1), and the following equation (2) is obtained by replacing "polygon" with "object". Satisfaction of contouring condition = the relevant pixel is a part of the object, transparent pixels exist in eight surrounding pixels, and control information for adding a contour of the object data is “added” (2) Therefore, (2) According to the formula, even if the pixel exists at the edge of the polygon constituting the object, the contouring condition is not satisfied unless the pixel is in contact with the outside of the object. That is, it is possible to detect only pixels that are edge portions of the object. Here, when the contouring condition is satisfied, the color of the pixel is changed to the color of the contour (steps S6 and S7 in FIG. 3). In addition,
For the number of pixels used as surrounding pixels,
The number may be other than eight.

After completion of the processing in the edge detection processing section 34, the writing section 35 writes each pixel for which the color data has been determined into the frame buffer 4. The contents of the processing will be described in the first embodiment. The contents are the same as those described above (steps S8 and S9 in FIG. 3). The process is performed on all the pixels in the temporary storage memory 32 (step S10 in FIG. 3), and the process on one target object ends. As a result, the object is displayed on the display screen with the outline added.

FIG. 13 shows the object exemplified in FIG.
This shows a state where the processing for O has been completed and the data has been written to the frame buffer 4. In the figure, O ′ is the final digital image of the object O, and the pixels at the edges are given the color of the outline. Further, pixels inside the object has a color of P _1, P _2, P ₃ the original polygon data is retained.

FIG. 14 shows a comparison between a case where an outline is added to an object (FIG. 14 (b)) and a case where the object is not contoured (FIG. 14 (a)), using one screen of a game device as an example. This screen shows a scene in which two objects representing a car are located in the distance near the horizon. In order to quickly recognize the existence and position of these objects that are the targets of the game operation, outlines have been added (b It turns out that the screen of ()) is more suitable.

As described above, by adding an outline to an object to be displayed by using the image processing apparatus according to the second embodiment, the object can be easily recognized. Operability can be improved. By providing control information for adding a contour to the object data, it is possible to select an object to which a contour is to be added, such as adding a contour only to an object to be operated.

Next, a third embodiment to which the present invention is applied will be described. Although the image processing apparatuses described in the first and second embodiments express the edges of polygons and objects as so-called contours for the purpose of making it easier to recognize the display object. The image processing apparatus according to the present embodiment intends to reduce jaggedness (anti-aliasing) at edges of polygons and objects to be displayed by performing translucent processing on the edges. FIGS. 15A and 15B are diagrams exemplifying a translucent process in an edge portion of a polygon. FIG. 15A shows a state where the translucent process is not performed, and FIG. 15B shows a state where the translucent process is performed.

FIG. 16 is a block diagram of the image processing apparatus according to the present embodiment, which has substantially the same configuration as the image processing apparatuses according to the first and second embodiments shown in FIG. As described above, the image processing apparatus according to the present embodiment differs from the image processing apparatuses according to the first and second embodiments only in the processing method for the detected edge part.
6 only in the functions of the edge detection processing section 34 'and the writing section 35'. Therefore, in the processing flow shown in FIG. 3, only the processing in step S7 is different from those in the first and second embodiments, and the contents are shown in the processing flow in FIG. In the figure, step S7 'is a different part. Hereinafter, based on FIG. 16 and FIG. 17, processing contents in the edge detection processing unit 34 ′ and the writing unit 35 ′, which are features of the present embodiment only, will be described.

As described above, the image of the polygon or object targeted by the drawing command is stored in the temporary storage memory 3.
2, and the color data of the pixel is read out one by one and sent to the edge detection processing unit 34 '.
First, the edge detection processing unit 34 'determines the contouring condition for the pixel to which the data is sent, based on the expression (1) or (2) as described above (step S6 in FIG. 17). .

Here, when the contouring condition is satisfied, that is, when it is determined that the pixel exists at the edge portion, the pixel is made translucent and the blend ratio is calculated (step S7 'in FIG. 17). -1). Translucent means that in determining the display color of the pixel, the color or background color of another polygon at the same position is blended with the color of the polygon to be processed (the color of the pixel). This means that the contribution ratio of the color of the polygon to be processed at this time is called a blend ratio. This blend ratio is calculated using the color data of the surrounding eight pixels used in the determination of the contouring condition.
It is calculated by the following equation (3). Blend ratio = number of non-transparent pixels in the 8 surrounding pixels / 8 (3)

FIG. 18 is a diagram for explaining a method of calculating the blend ratio. Here, a polygon image of the polygon P shown in FIG. 4 and the like is used as an example. FIG.
(A) shows the determination result of the contouring condition for each pixel, and the pixel indicated by ● is a pixel determined to be an edge portion, that is, a pixel to be translucent. (A-a), (A-b), and (A-c) of FIG. 4 are diagrams respectively showing the pixels a, b, and c of (A) and their peripheral pixels. As shown in (A-a), the blending ratio of the pixel a is 2/8 according to the above (3) because two of the surrounding eight pixels are not transparent. Similarly, the blend ratios of pixels b and c are 5/8 and 7 respectively.
/ 8. FIG. 4B shows the result of calculating the blend ratio for all the pixels to be made translucent. In the apparatus according to the present embodiment, eight peripheral pixels are used when calculating the blend ratio. However, an apparatus using a different number of peripheral pixels may be used.

The pixel data for which the translucency and the blend ratio have been calculated by the edge detection processing unit 34 'are then sent to the writing unit 35' where the final color determination and frame buffer 4 is written. First, the color data of the pixel at the same position (coordinate) as the pixel to be processed is read from the frame buffer 4 (step S7'-2 in FIG. 17). Next, the color data (the color data of the polygon to be processed) sent from the edge detection processing unit 34 'and the read color data are subjected to a blending process to determine the final color to be written to the frame buffer 4 ( Step S7'-3) in FIG. The final color is obtained by the following equation (4). Final color = A × k + B × (1−k) (4) where A: color data of the polygon to be processed B: color data read from the frame buffer k: the above blend ratio If the final color is determined As in the case of the first and second embodiments, through the write determination (step S8 in FIG. 17),
Writing to the frame buffer 4 is performed. On the other hand, if the contouring condition in the edge detection processing unit 34 'is not satisfied, the translucent processing described so far is not performed, and the writing determination to the frame buffer 4 (step S8 in FIG. 17) is performed. Is made.

The processing for one pixel described above is performed on all the pixels in the temporary storage memory 32, thereby completing the processing for one polygon or object. As a result, an image of a polygon or an object whose edge part has been translucently processed is displayed. FIG. 19 is a diagram showing a comparison between display images when the edge portion is translucently processed (FIG. 19B) and when it is not (FIG. 19A). This is the rendering result of the polygon illustrated in FIG. 18, and in FIG. 18B, it can be seen that the edge portion of the polygon is blended with the background color expressed in white and thinned. As described above, the degree of the thinness is determined by the blending ratio shown in FIG. 18B, and the smaller the value is, the smaller the contribution ratio of the polygon color is and the lighter the color becomes.

By using the image processing apparatus according to the third embodiment described above, the edges of polygons and objects to be displayed can be translucently processed, and the jaggedness at the edges can be reduced. . In addition,
Detects the edges of polygons and objects to be displayed,
It can be said that the third embodiment also has the same purpose as the first and second embodiments in that a good display screen is generated by performing a special drawing on that portion. It should be noted that the blend ratios and the final color calculation formulas using the blend ratios shown in the above formulas (3) and (4) are examples. The protection scope of the present invention is not limited to the above embodiments, but extends to the inventions described in the claims and their equivalents.

[0055]

As described above, according to the embodiments of the present invention, an edge portion in a digital image of an object to be displayed can be detected and a specific process can be performed on the edge portion. Therefore, when a process of adding a contour to an edge portion is performed, there is an effect that the display target can be easily recognized on the display screen. Further, in the case where the translucent processing is performed on the edge portion, there is an effect of so-called anti-aliasing, which reduces jaggedness at the edge portion of the display object.

[Brief description of the drawings]

FIG. 1 is a configuration diagram according to a first embodiment of an image processing apparatus to which the present invention has been applied.

FIG. 2 is a diagram illustrating an example of adding a contour to a polygon;

FIG. 3 is a diagram illustrating a processing flow in a rendering unit of the image processing apparatus according to the first embodiment.

FIG. 4 is a diagram conceptually illustrating polygon data sent to a drawing unit 31;

FIG. 5 shows a temporary storage memory 3 of a polygon P illustrated in FIG.
FIG. 6 is a diagram showing a state where the image is drawn on a second surface;

FIG. 6 is a diagram for explaining determination based on contouring conditions.

FIG. 7 is a diagram illustrating a determination result based on a contouring condition for all pixels regarding the polygon P illustrated in FIG. 4;

FIG. 8 shows a polygon P shown in FIG.
FIG. 7 is a diagram showing a state where data has been written to a.

FIG. 9 is a diagram illustrating a display example in a case where a contour is added to a plurality of polygons and a case where a contour is not added.

FIG. 10 is a diagram showing a display example when an outline is added only to a specific polygon.

FIG. 11 is a diagram showing an example in which two objects are displayed overlapping each other.

FIG. 12 is a diagram conceptually illustrating object data sent to a drawing unit 31;

FIG. 13 is a diagram showing a state in which the object O illustrated in FIG. 12 has been written into the frame buffer 4;

FIG. 14 is a diagram showing a display example in a case where a contour is added to an object on a single screen of the game device;

FIG. 15 is a diagram illustrating a translucent process at an edge portion of a polygon.

FIG. 16 is a configuration diagram of an image processing apparatus according to a third embodiment.

FIG. 17 is a diagram illustrating a processing flow of the image processing apparatus according to the third embodiment.

FIG. 18 is a diagram for explaining a method of calculating a blend ratio.

FIG. 19 is a diagram illustrating a comparison between display images when an edge portion is subjected to translucent processing and when it is not.

FIG. 20 is a diagram showing a rough configuration of a general image processing apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 CPU 2 Geometry part 3 Rendering part 4 Frame buffer 31 Drawing part 32 Temporary memory 33 Reading part 34 Edge detection processing part 35 Writing part

Claims (12)

[Claims] 1. An image processing apparatus for drawing an object group having three-dimensional coordinates on a two-dimensional display screen consisting of a series of pixels, wherein the edge drawing method of a drawing target graphic drawn on the display screen is performed by one of the following: When the drawing target graphic is drawn on the display screen, for every pixel included in a region of a predetermined size including the one drawing target graphic in the display screen, the pixel is A first step of determining whether or not the pixel is present at an edge of one drawing target graphic; and a second step of performing a predetermined process only on pixels determined to be present at the edge in the first step. An edge drawing method, comprising the steps of: 2. The method according to claim 1, wherein the determination in the first step is such that the pixel exists in the one drawing target graphic,
And, when one or more pixels out of the predetermined number of pixels located around the pixel do not exist in the one drawing target graphic, it is determined that the pixel exists in the edge portion. Edge drawing method to be used. 3. The method according to claim 1, wherein the one drawing object graphic is one polygon, and the predetermined process in the second step is a process for a pixel determined to be present in the edge portion. An edge drawing method, characterized in that the drawing color is a process of setting the drawing color to a color expressing the outline of the polygon. 4. The method according to claim 1, wherein the one drawing target graphic is a graphic composed of a set of polygons representing one object, and the predetermined process in the second step is An edge drawing method, characterized in that the drawing color of a pixel determined to be present in an edge portion is a color representing a contour of the object. 5. The image processing method according to claim 1, wherein the predetermined processing in the second step includes: rendering a drawing color of a pixel determined to be present in the edge portion with a color of the one drawing target graphic; An edge drawing method, which is a blending process of blending and determining colors possessed by the pixel before drawing the one drawing target graphic. 6. The image processing apparatus according to claim 5, wherein the color blending in the blending process is performed according to the number of pixels existing in the one drawing target graphic out of a predetermined number of pixels located around the pixel. An edge drawing method characterized by being performed at a ratio. 7. An image processing apparatus for drawing an object group having three-dimensional coordinates on a two-dimensional display screen, wherein a drawing target figure is converted into pixel units constituting the display screen based on a drawing command from a CPU. An image processing device that writes a digital image of the data of the drawing into a frame buffer, wherein colors of all pixels included in an area of a predetermined size including a digital image of one of the graphics to be drawn on the display screen; A temporary memory for temporarily storing data, wherein a color data of all the pixels is initialized each time the drawing command for one drawing target graphic is received; After the temporary storage memory is initialized based on the drawing command, from the data of the one drawing target graphic given together with the drawing command, A drawing unit for generating a digital image of one drawing target figure and writing color data of pixels constituting the digital image into the temporary storage memory; and storing the data in the temporary storage memory after writing by the drawing unit. Reading means for reading, for each pixel, color data of the target pixel and color data of a predetermined number of peripheral pixels located around the target pixel from the temporary storage memory for each pixel; It is determined from the color data read in step 1 whether or not the target pixel exists at the edge of the digital image generated by the drawing means. If it is determined that the target pixel exists at the edge, the target pixel Is changed by a predetermined process, and if it is not determined that the color data exists in the edge portion, the color of the target pixel is changed. Edge part detection processing means for maintaining the data as it is, and, after processing by the edge part detection processing means, the digital image of the one drawing target graphic is stored in the frame buffer based on the color data of the target pixel. An image processing apparatus, comprising: a writing unit that writes data into a device. 8. The edge part in the edge detection processing means according to claim 7, wherein the initialization of the temporary storage memory is to make the color data of all the pixels stored in the temporary storage memory transparent. It is determined whether or not the target pixel is in the edge portion, if the color data of the target pixel is not transparent and the color data of one or more of the peripheral pixels is transparent. An image processing apparatus, which is performed by determining that there is an image. 9. The method according to claim 7, wherein said one drawing target graphic is one polygon, and said predetermined processing when said edge detection processing means determines that said figure is present in an edge portion. An image processing apparatus, wherein color data of a target pixel is converted into a color expressing the outline of the polygon. 10. The drawing according to claim 7, wherein said one drawing target figure is a figure representing one object consisting of a set of polygons, and said edge detection processing means determines that said drawing exists at an edge portion. The image processing apparatus according to claim 1, wherein the predetermined process is a process of setting the color data of the target pixel as a color representing the contour of the object. 11. The method according to claim 7, wherein the predetermined processing when the edge detection processing means determines that the target pixel exists in the edge portion includes: An image processing apparatus, comprising: a blending process for forming a color obtained by blending color data of a pixel at the same position as a pixel with color data of the target pixel. 12. The image processing apparatus according to claim 11, wherein the blending of the color data in the blending process is performed at a rate corresponding to the number of pixels having non-transparent color data among the peripheral pixels. .