JP2012128580A - Information processing unit, information processing method and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an information processing unit capable of high-speed redrawing in a manner coping with a color change of original data with comparatively small memory usage.SOLUTION: In an information processing unit, a CPU 101 calculates opacity information indicating opacity of each pixel forming an edge part of a first figure based on shape information indicating a shape of the first figure and stores the opacity information on the first figure in RAM 103. Thereafter, the CPU 101 determines whether or not the opacity information on the first figure usable when drawing a second figure is stored. Thereafter, if it is determined that the opacity information on the first figure usable when drawing the second figure is stored, the CPU 101 draws the second figure based on the opacity information on the first figure.

Description

  The present invention relates to a technique for drawing graphics.

  Conventionally, in graphics drawing processing including drawing objects such as image data, graphic data, and character data, a method of storing and reusing a drawing result image for each drawing object in order to increase processing speed at the time of redrawing Is known (see, for example, Patent Document 1). Also known is a method of storing and reusing edge coordinates for each scan line of a drawing object (for example, see Patent Document 2). In these methods, once a graphics drawing process is performed, an image of a drawing result and edge coordinates for each scan line are stored in a memory. Then, the image data and edge coordinates stored in the memory at the time of redrawing are used to increase the drawing speed.

JP-A-5-204356 JP-A-9-281948

  However, in the method of storing the drawing result image in the memory, since the data size of the image data is generally large, there is a problem that a corresponding memory is required. In addition, the method of saving image data has a problem that it cannot be reused when the color of the original drawing object is changed.

  The method of saving edge coordinates can be reused even when the color of the drawing object changes, but in order to perform anti-aliasing processing (processing that draws the edge portion smoothly), the color of the edge portion A process requiring a calculation load is necessary for the determination. In addition, a method of increasing the number of scan lines is often used in order to perform high-quality anti-aliasing processing. In this case, however, there is a problem that memory consumption increases because edge coordinates to be stored increase.

  Therefore, an object of the present invention is to perform redrawing at a high speed by a method that can cope with a color change of the original data with a relatively small memory usage.

  The information processing apparatus according to the present invention, based on shape information indicating the shape of the first graphic, calculation means for calculating opacity information indicating the opacity of each pixel constituting the edge portion of the first graphic; Storage means for storing the opacity information of the first graphic calculated by the calculation means in the storage means, and opacity information of the first graphic that can be used when drawing the second graphic is stored. And determining means for determining whether or not the opacity information of the first graphic that can be used when drawing the second graphic is stored by the determining means. And a drawing means for drawing the second graphic based on the opacity information of the first graphic.

  According to the present invention, it is possible to perform redrawing at a high speed by a method that can cope with the color change of the original data with a relatively small memory usage.

It is a figure which shows the structure of the information processing apparatus which concerns on embodiment. It is a figure which shows typically a part of drawing buffer in the information processing apparatus which concerns on embodiment. FIG. 2 is a diagram showing an XML (Extensible Markup Language) document in which a circle represented by a dotted line is defined. It is a figure for demonstrating the edge extraction in the case of an anti-aliasing process. It is a figure for demonstrating the calculation method of the opacity of the pixel which comprises circular. It is a figure which shows the result of having calculated | required the opacity of each pixel of a rectangle including a circle by the method demonstrated using FIG. It is a flowchart which shows the flow of a process of the information processing apparatus which concerns on 1st Embodiment. It is a figure which shows the XML document which defined the graphics which the information processing apparatus which concerns on embodiment draws. It is a figure which shows the drawing range of the stroke part of the graphics shown in FIG. It is a figure which shows the opacity information of each pixel in the case of drawing only the stroke part of the graphics shown in FIG. It is a flowchart which shows the flow of a process of the information processing apparatus which concerns on 2nd Embodiment.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments to which the invention is applied will be described in detail with reference to the accompanying drawings.

  First, the first embodiment will be described. FIG. 1 is a diagram illustrating a configuration of the information processing apparatus according to the first embodiment. Hereinafter, the configuration of the information processing apparatus according to the present embodiment will be described with reference to FIG.

  In FIG. 1, a CPU 101 controls the entire information processing apparatus as a system control unit. The ROM 102 is a read-only memory that stores the control program of the CPU 101 and various fixed data. The RAM 103 is a rewritable memory composed of SRAM, DRAM, and the like, and stores program control variables and the like. Various setting parameters, various work buffers, and the like are also stored in the RAM 103. The display unit 104 is configured using an LCD or the like, and performs image display. The operation unit 105 includes a keyboard, a pointing device, and the like, and is used by the operator to perform various input operations. The system bus 106 connects the units 101 to 105 so that they can communicate with each other.

  FIG. 2 is a diagram schematically showing a part of a drawing buffer in the information processing apparatus according to the present embodiment. As shown in FIG. 2, the drawing buffer represents a coordinate space with the upper left as the origin (0, 0), and one rectangle denoted by 201 corresponds to one pixel. The drawing buffer exists in the RAM 103, and each pixel is represented by 1 byte (8 bits) for each of RGB and 3 bytes (24 bits) in total. Here, RGB is a value representing each of red, green and blue color components. A circle indicated by a dotted line in FIG. 2 is a circle to be drawn in this coordinate space in this embodiment. In such a drawing buffer, the arrangement of pixels in the X-axis direction is particularly called a scan line. A drawing result is displayed on the display unit 104 based on the color information of each pixel stored in the drawing buffer.

  FIG. 3 is a diagram showing an XML (Extensible Markup Language) document in which a circle represented by a dotted line in FIG. 2 is defined. The XML document shown in FIG. 3 is described in SVG (Scalable Vector Graphics) format. This XML document means that a circle with a radius of 5 pixels centered on coordinates (8, 8) is drawn in opaque blue in a coordinate space of 16 pixels wide and 16 pixels high. The information processing apparatus according to the present embodiment analyzes the XML document shown in FIG. 3 and displays graphics described in the XML document on the display unit 104.

  The XML document shown in FIG. 3 describes that a circle is drawn. Since each pixel is a rectangle, a technique called anti-aliasing is used to represent the circle. Anti-aliasing is a technique for making jagged edges represented by rectangular pixels inconspicuous by applying translucent processing to the pixels at the edge (end) of the figure. Before describing the processing of the information processing apparatus according to the present embodiment, anti-aliasing processing will be described with reference to FIGS.

  FIG. 4 is a diagram for explaining edge extraction during anti-aliasing. In the anti-aliasing process, it is necessary to calculate the opacity (opacity) of the edge portion of the figure. For this purpose, first, a virtual coordinate space is assumed in which each pixel is divided into two in both the X-axis direction and the Y-axis direction, and an intersection between a circular edge portion to be drawn and each scan line is obtained. The black points on the circumference shown in FIG. 4 are the intersections. From the coordinate set (edge coordinate list) of the edge part thus obtained, the opacity of each pixel constituting the circle is obtained.

  FIG. 5 is a diagram for explaining a method of calculating the opacity of pixels constituting a circle. In the case of the pixel indicated by reference numeral 501 in FIG. 5, it can be calculated from the intersection shown in FIG. 4 that three of the four divided virtual pixels are filled. Since four virtual pixels correspond to one actual pixel, if the total opacity is set to 4, this pixel can be regarded as having an opacity of 3. When drawing this pixel in the drawing buffer, drawing is performed after alpha blending with the background color is performed to determine the color. For example, if the background color is opaque white, the circle is opaque blue, and therefore the pixel indicated by 501 is a color synthesized with a ratio of 1 for the background white and 3 for the blue.

  FIG. 6 is a diagram illustrating a result of obtaining the opacity of each rectangular pixel including a circle by the method described with reference to FIG. Here, 0 means completely transparent and 4 means completely opaque. Although the figure to be drawn is an opaque circle, as shown in FIG. 6, semitransparent (opacity is 1 to 3) pixels appear at the edge of the circle.

  In FIGS. 4 and 5, a virtual coordinate space divided into two in both the X-axis direction and the Y-axis direction is assumed. However, it is possible to perform higher-quality anti-aliasing by dividing more finely. There are other methods for obtaining the opacity of the edge portion, and the method described here is not necessarily used.

  FIG. 7 is a flowchart showing the flow of processing of the information processing apparatus according to the present embodiment. Generally, graphics to be displayed are composed of a plurality of figures, images, and characters. These figures, images, and characters are referred to as drawing objects. FIG. 7 shows a flow when processing one of the drawing objects constituting the graphics.

  As shown in FIG. 7, first, the CPU 101 determines whether or not usable opacity information (opacity information) is stored in a RAM (memory) 103 for a drawing object to be drawn (step S701). Here, the opacity information is information indicating the opacity of each pixel shown in FIG. Here, even if the opacity information about the circle is stored in the RAM 103, if the size of the circle is different, the CPU 101 determines that it cannot be used. This is because if the sizes of the circles are different, the pixels of the edge portion in particular change, so that the opacity information stored in the RAM 103 cannot be used as it is. Further, when drawing a drawing object such as a rectangle, the CPU 101 determines that the drawing object cannot be used if the rotation angle of the drawing object is different. For drawing objects with different colors, if the opacity information of the drawing object is stored in the RAM 103, the CPU 101 determines that usable opacity information is stored in the RAM 103.

  If it is determined in step S701 that usable opacity information is not stored in the RAM 103, the CPU 101 creates an edge coordinate list of the drawing object as described with reference to FIG. 4 (step S702). Next, as described with reference to FIGS. 5 to 6, the CPU 101 calculates the opacity (opacity) of each pixel from the edge coordinate list, and stores the result (opacity information) in the RAM 103 (step S <b> 703). Next, the CPU 101 calculates the drawing color of each pixel from the opacity information and the color information of the drawing object (step S704). Next, the CPU 101 draws the drawing color of each pixel in the drawing buffer (step S705).

  On the other hand, if it is determined in step S701 that usable opacity information is stored in the RAM 103, the CPU 101 calculates the drawing color of each pixel from the opacity information stored in the RAM 103 and the color information of the drawing object. (Step S704). Next, the CPU 101 draws the drawing color of each pixel in the drawing buffer (step S705).

  In step S <b> 703, when the CPU 101 stores opacity information of a certain drawing object (first graphic) in the RAM 103, the CPU 101 stores the drawing object shape information in association with the opacity information in the RAM 103. The CPU 101 determines whether opacity information that can be used for a drawing object (second graphic) to be drawn is stored based on shape information of the drawing object (first graphic).

  Since the opacity information of each pixel stored in step S703 is a value from 0 to 4 as shown in FIG. 6, a data amount of 3 bits per pixel is sufficient. In general, there is known a method of storing all the drawing results in the RAM 103 and reusing them. In this case, in the case of graphics of 8 bits for each of RGB, 24 bits of data are required per pixel. In the present embodiment, although the process shown in step S705, that is, the process of calculating the drawing color of each pixel from the opacity information is required, the data stored in the RAM 103 as a cache can be suppressed to about 1/8. Even if the colors of the objects are different, this opacity information can be reused.

  In this embodiment, the range of opacity information that each pixel can take is set to 0 to 4. However, in order to draw higher-quality graphics, the range of opacity information is set to 0 to 16, 0 to 64, or the like. May be. Further, in this embodiment, the method of storing the opacity information of each pixel shown in FIG. 6 in the RAM 103 is used. However, among the opacity information shown in FIG. 6, the opacity of the pixels along the circumference (the outline of the object). Only information may be stored. By doing so, the memory consumption may be further suppressed.

  Next, a second embodiment will be described. The configuration of the information processing apparatus according to the present embodiment is the same as that of the information processing apparatus according to the first embodiment shown in FIG.

  FIG. 8 is a diagram showing an XML document that defines graphics to be drawn by the information processing apparatus according to the present embodiment. This XML document describes that in addition to the circle shown in FIG. 3, the circumferential portion is painted in red with a width of 4 pixels and an opacity of 0.5. That is, the XML document shown in FIG. 8 defines the second partial graphic in addition to the shape information indicating the outline of the circle (first partial graphic) shown in FIG. 3 and the color information of the first partial graphic. The line width information indicating the line width from the contour line and the color information of the second partial figure are described. In SVG, the opacity indicated by the stroke-opacity attribute takes a value of 0 to 1, with 0 being completely transparent and 1 being completely opaque. In the case of SVG, the paint color indicated by the fill attribute of the defined object is a color that paints the inside of the graphic, and the paint color indicated by the stroke attribute is a color that paints the outer periphery of the graphic. In the present embodiment, the process of painting the inner part of the graphic is called fill processing, and the process of painting the outer peripheral part of the graphic is called stroke processing.

  FIG. 9 is a diagram showing a drawing range of the stroke portion of the graphics shown in FIG. According to the XML document shown in FIG. 8, since the stroke width (line width information) is 4 pixels, the stroke is sandwiched between the two dotted lines (first partial graphic 901 and second partial graphic 902) in FIG. The area will be painted by stroke processing. Hereinafter, an area inside the first partial graphic 901 is referred to as a fill part, and an area sandwiched between the first partial graphic 901 and the second partial graphic is referred to as a stroke part.

  FIG. 10 is a diagram showing the opacity information of each pixel when only the stroke portion of the graphics shown in FIG. 8 is drawn. Here, 0 means completely transparent and 4 means completely opaque. This opacity information can be calculated by creating an edge coordinate list in the same manner as the method described with reference to FIGS. In the graphics shown in FIG. 8, the stroke-opacity attribute is 0.5, but the opacity information shown in FIG. 10 does not consider the value of the stroke-opacity attribute.

  FIG. 11 is a flowchart showing a flow of processing of the information processing apparatus according to the second embodiment. As shown in FIG. 11, the CPU 101 first determines whether or not the drawing object is composed of both a fill part and a stroke part (step S1101). Here, when it is determined that there is only one of the fill portion and the stroke portion, the subsequent processing is the same as the processing shown in FIG.

  On the other hand, if it is determined in step S1101 that the drawing object is composed of both the fill part and the stroke part, the CPU 10 processes the fill part and the stroke part separately. First, the CPU 101 determines whether or not usable opacity information corresponding to the fill portion is stored in the RAM 103 (step S1102). If it is determined that usable opacity information corresponding to the fill portion is not stored in the RAM 103, the CPU 101 creates an edge coordinate list of the fill portion (S1103), as in steps S702 and S703. Next, the CPU 101 calculates opacity information of each pixel in the fill portion and stores it in the RAM 103 (step S1104). At this time, the opacity information is stored in the RAM 103 in association with the shape information of the fill portion. In step S1102, whether or not usable opacity information corresponding to the fill portion is stored in the RAM 103 is determined based on the shape information. Step S1104 is a processing example of the first calculation unit and the first storage unit. In addition, the partial storage area of the RAM 103 in which the opacity information is stored in step S1104 is a configuration that is an application example of the first storage unit.

  Next, the CPU 101 calculates the drawing color of each pixel in the fill portion from the opacity information stored in the RAM 103 and the color information of the drawing object (step S1105). Next, the CPU 101 draws the drawing color of each pixel in the fill portion in the drawing buffer (step S1106).

  On the other hand, if it is determined in step S1102 that usable opacity information corresponding to the fill portion is stored in the RAM 103, the CPU 101 calculates the drawing color of each pixel from the opacity information and the color information of the drawing object. (Step S1105). Next, the CPU 101 draws the drawing color of each pixel in the drawing buffer (step S1106).

  Next, the CPU 101 determines whether or not usable opacity information corresponding to the stroke portion is stored in the RAM 103 (step S1107). If it is determined that usable opacity information corresponding to the stroke portion is not stored in the RAM 103, the CPU 101 creates an edge coordinate list of the stroke portion (step S1108). Next, the CPU 101 calculates opacity information for each pixel in the stroke portion and stores it in the RAM 103 (step S1109). At this time, the opacity information is stored in the RAM 103 in association with the shape information and line width information of the fill portion. In step S1107, whether or not usable opacity information corresponding to the stroke portion is stored in the RAM 103 is determined based on the shape information and the line width information. Note that step S1109 is a processing example of the second calculation unit and the second storage unit. In addition, the partial storage area of the RAM 103 in which the opacity information is stored in step S1109 is a configuration serving as an application example of the second storage unit.

  Next, the CPU 101 calculates the drawing color of each pixel in the stroke portion from the opacity information stored in the RAM 103 and the drawing color of the drawing object (step S1110). Next, the CPU 101 draws the drawing color of each pixel in the stroke portion in the drawing buffer (step S1111).

  On the other hand, when it is determined in step S1107 that usable opacity information corresponding to the stroke portion is stored in the RAM 103, the CPU 101 draws each pixel of the stroke portion from the opacity information and the color information of the drawing object. A color is calculated (step S1110). Next, the CPU 101 draws the drawing color of each pixel in the stroke portion in the drawing buffer (step S1111).

  In addition, when calculating the drawing color of each pixel in steps S1105 and S1110, the values of the fill-opacity attribute and the stroke-opacity attribute are also considered. If the method of this embodiment is used, opacity information can be cached and reused for a drawing object in which both a fill part and a stroke part are specified. In addition to the fill part and the stroke part, a drawing object composed of a plurality of drawing elements can be processed using the same method.

  The information processing apparatus having the display unit 104 has been described above as an example, but the present invention can be applied to any apparatus having a display unit such as a printing apparatus, a camera, a copying machine, a scanner, and a television. Further, the present invention is not limited to graphics, and can be applied to graphics such as images, moving images, and characters.

  As described above, according to the above-described embodiment, it is possible to perform redrawing at a high speed by a method that can cope with the color change of the original data with a relatively small memory usage.

  The present invention can also be realized by executing the following processing. That is, software (program) that realizes the functions of the above-described embodiments is supplied to a system or apparatus via a network or various storage media, and a computer (or CPU, MPU, or the like) of the system or apparatus reads the program. It is a process to be executed.

Claims (9)

Calculation means for calculating opacity information indicating the opacity of each pixel constituting the edge portion of the first graphic based on the shape information indicating the shape of the first graphic;
Storage means for storing in the storage means the opacity information of the first graphic calculated by the calculation means;
Determination means for determining whether or not the opacity information of the first graphic that can be used in drawing the second graphic is stored;
When it is determined by the determination means that the opacity information of the first graphic that can be used when drawing the second graphic is stored, based on the opacity information of the first graphic, An information processing apparatus comprising drawing means for drawing the second graphic.   The determination unit can be used when drawing the second graphic based on the shape information of the first graphic stored in the storage unit in association with the opacity information of the first graphic. The information processing apparatus according to claim 1, wherein it is determined whether opacity information of the first graphic is stored. Opacity information indicating the opacity of each pixel constituting the edge portion of the first partial graphic is calculated based on the shape information defining the outline of the first partial graphic that is a part of the first graphic. First calculating means;
First storage means for storing opacity information of the first partial graphic calculated by the first calculation means in a first storage means;
Based on the line width information indicating the line width from the outline line, the opacity of each pixel constituting the edge part of the second partial graphic that is the other part of the first graphic defined by the line width information Second calculating means for calculating opacity information indicating
Second storage means for storing the opacity information of the second partial graphic calculated by the second calculation means in a second storage means;
Whether at least one of the opacity information of the first partial graphic and the opacity information of the second partial graphic is stored as opacity information that can be used when drawing the second graphic Determining means for determining whether or not;
When it is determined by the determining means that opacity information that can be used when drawing the second graphic is stored, the stored opacity information of the first partial graphic and the second graphic An information processing apparatus comprising: a drawing unit that draws the second graphic based on at least one of the opacity information of the partial graphic.   The determination means is configured to draw the second graphic based on the shape information of the first partial graphic stored in the first storage means in association with the opacity information of the first partial graphic. The information processing apparatus according to claim 3, wherein it is determined whether opacity information of the first partial graphic that can be used at the time is stored.   The determination means is based on the shape information and the line width information of the second partial graphic stored in the second storage means in association with the opacity information of the second partial graphic. 5. The information processing apparatus according to claim 3, wherein opacity information of the second partial graphic that can be used when drawing the graphic is stored. An information processing method executed by an information processing apparatus,
A calculation step of calculating opacity information indicating the opacity of each pixel constituting the edge portion of the first graphic based on the shape information indicating the shape of the first graphic;
A storage step of storing in the storage means the opacity information of the first graphic calculated by the calculation step;
A determination step of determining whether opacity information of the first graphic that can be used when drawing the second graphic is stored;
When it is determined in the determination step that the opacity information of the first graphic that can be used when drawing the second graphic is stored, based on the opacity information of the first graphic, A drawing step of drawing the second graphic. An information processing method executed by an information processing apparatus,
Opacity information indicating the opacity of each pixel constituting the edge portion of the first partial graphic is calculated based on the shape information defining the outline of the first partial graphic that is a part of the first graphic. A first calculation step;
A first storage step of storing in the first storage means the opacity information of the first partial graphic calculated by the first calculation step;
Based on the line width information indicating the line width from the outline line, the opacity of each pixel constituting the edge part of the second partial graphic that is the other part of the first graphic defined by the line width information A second calculation step of calculating opacity information indicating
A second storage step of storing the opacity information of the second partial graphic calculated in the second calculation step in a second storage means;
Whether at least one of the opacity information of the first partial graphic and the opacity information of the second partial graphic is stored as opacity information that can be used when drawing the second graphic A determination step for determining whether or not;
If it is determined in the determination step that opacity information that can be used in drawing the second graphic is stored, the stored opacity information of the first partial graphic and the second graphic And a drawing step of drawing the second graphic based on at least one of the opacity information of the partial graphic. A calculation step of calculating opacity information indicating the opacity of each pixel constituting the edge portion of the first graphic based on the shape information indicating the shape of the first graphic;
A storage step of storing in the storage means the opacity information of the first graphic calculated by the calculation step;
A determination step of determining whether opacity information of the first graphic that can be used when drawing the second graphic is stored;
When it is determined in the determination step that the opacity information of the first graphic that can be used when drawing the second graphic is stored, based on the opacity information of the first graphic, A program for causing a computer to execute a drawing step for drawing the second graphic. Opacity information indicating the opacity of each pixel constituting the edge portion of the first partial graphic is calculated based on the shape information defining the outline of the first partial graphic that is a part of the first graphic. A first calculation step;
A first storage step of storing in the first storage means the opacity information of the first partial graphic calculated by the first calculation step;
Based on the line width information indicating the line width from the outline line, the opacity of each pixel constituting the edge part of the second partial graphic that is the other part of the first graphic defined by the line width information A second calculation step of calculating opacity information indicating
A second storage step of storing the opacity information of the second partial graphic calculated in the second calculation step in a second storage means;
Whether at least one of the opacity information of the first partial graphic and the opacity information of the second partial graphic is stored as opacity information that can be used when drawing the second graphic A determination step for determining whether or not;
If it is determined in the determination step that opacity information that can be used in drawing the second graphic is stored, the stored opacity information of the first partial graphic and the second graphic A program for causing a computer to execute a drawing step of drawing the second graphic based on at least one of the opacity information of the partial graphic.

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