JP2006139342A - Image processor and image processing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image processor and an image processing method for improving a processing speed in the overlap processing of plotting objects, and for reducing a necessary memory capacity. <P>SOLUTION: A plotting part 1 performs plotting processing according to a plotting instruction to generate plotting data, and makes a plotting data storage part 2 store the plotting data. The data structure of the plotting data to be generated selects any of several data structures different from each other according to data to be included. At the time of carrying out the overlap of two plotting objects, data necessary for expressing the overlapped plotting data are specified according to the data structures owned by the two plotting objects to be overlapped and conditions(for example, the presence/absence of a blend mode, environment variables or mask data) at the time of overlapping the plotting objects, and the minimum data structure including the data is decided for use. Thus, it is possible to drastically reduce necessary memory capacity in comparison with the case that all data are owned by all plotting objects. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image processing technique for performing image drawing processing.

  In general, when an image is output, a drawing process for forming a bitmap image is performed in accordance with a drawing command output from an application program or an operating system, and the bitmap image is output. Alternatively, there is a case where an intermediate code is once generated from a drawing command and a bitmap image is formed from the intermediate code. The drawn drawing command is generated for each drawing object, and there are cases where drawing is performed so that a plurality of drawing objects overlap each other during the drawing process. When drawing objects overlap in this way, information such as attributes of the respective drawing objects is held, and drawing processing proceeds while considering the attributes of the drawing objects that overlap.

  In this way, since the overlapping of the drawing objects has to be processed, the conventional drawing processing is performed while holding all the information related to the overlapping for all the drawing objects. For example, when drawing as a bitmap image, a color plane that holds the color information of each pixel, an alpha plane that holds an alpha value that indicates transparency, and a shape value that indicates a clip shape including blur is held. The attributes of each pixel, such as a shape plane and a mask plane that holds a mask value indicating a figure shape, are held for each pixel.

  Also, as one of the drawing processing methods having an overlap, there is a method using a planar map that holds data for each graphic divided for each overlapping portion during the drawing processing. In the case of this method, attribute information such as color information, alpha value, shape value, and mask value is held for each divided figure. Therefore, since it does not hold every pixel as compared with the bitmap image, it is possible to reduce the required memory amount and improve the processing speed.

  However, in many mixing processes, not all attribute information is used for mixing, and there are many attributes that do not affect the overlay process depending on the mixing conditions and the state of the input image. Therefore, when there are many attributes that do not affect the overlay process, there is a problem that a large amount of memory is used for information that is not used, resulting in a decrease in processing speed.

  For example, Patent Document 1 describes a technique for reducing the amount of data to be retained by compressing the result of the overlay process. However, although the data amount of the processing result can be reduced, since all the attribute information is retained when performing the superimposition process, the superimposition process itself requires a lot of memory. Further, processing time is required, and further, processing time for performing compression after the overlay processing is also required.

JP-A-11-316831

  The present invention has been made in view of the above-described circumstances, and an object thereof is to provide an image processing apparatus and an image processing method that improve the processing speed in the overlay processing of drawing objects and reduce the required memory capacity. To do.

  The present invention is an image processing apparatus and an image processing method for generating drawing data by performing drawing processing including drawing object superimposition processing according to a drawing command, wherein a plurality of data structures can be taken as drawing data. To do. Then, when performing drawing object superimposition processing, the data structure of the rendered drawing data after superimposition is changed to the data structure of the two drawing objects to be superimposed and the conditions for superimposition (for example, blend mode and environment variables, It depends on whether or not there is mask data. In general, the data structure is adjusted to a larger amount of data, but in the case of drawing data, conversely, the drawing data after overlapping is less than the data structure of the drawing object before overlapping. It can be expressed in structure. In such a case, it can be determined that a data structure that can be expressed by a small amount of data is used.

  As the data structure, it is possible to take a data structure including color data, color data and transparency, color data, transparency and shape value, and the color data includes single-color gradation data, three-color color data, four-color color. A data structure that includes any of the data can be selectively used. For example, when transparency processing is performed, transparency or a shape value is required. However, when the transparency is made opaque, the transparency and the shape value are not necessary, and a data structure not including these data can be used.

  As drawing data, various types of drawing data can be generated, such as bitmap data, the above-described planar map data, or edge list data divided for each section resulting in the same drawing result for each scan line. .

  According to the present invention, when drawing data is held in the storage unit, only necessary data can be held, and a required memory capacity can be reduced. Further, since the amount of data read from the storage means can be greatly reduced depending on the drawing data, the time required for the drawing process can be shortened. Furthermore, since the data structure of the drawing data after superposition is determined at the time of superposition processing, the data that the final drawing processing result must hold can be suppressed to the minimum necessary data amount. The processing can be held as it is without performing processing such as conversion and compression, and there is an effect that an improvement in processing speed can be expected.

  FIG. 1 is a block diagram showing an embodiment of the present invention. In the figure, 1 is a drawing unit, and 2 is a drawing data storage unit. The drawing unit 1 performs drawing processing according to a drawing command to generate drawing data, and stores the drawing data in the drawing data storage unit 2. Depending on the drawing command, the drawing data of the drawing object that has been drawn so far is read out from the drawing data storage unit 2, and an overlay process and a logical operation process with a new drawing object are also performed. In the present invention, the data structure of the drawing data to be generated takes one of several data structures that differ depending on the data to be included. An example of a possible data structure will be described later. This data structure is determined during the drawing process.

  For example, when performing overlay processing between drawing objects, the data structure of each of the two drawing objects to be overlaid and the conditions for superposition (for example, blend mode indicating the overlay method, overlay Based on the environment variables at the time of processing, the presence / absence of mask data, etc., data necessary for expressing the superimposed drawing data is specified, and it is determined that the minimum data structure including the data is used. Then, drawing data having the data structure is generated and held in the drawing data storage unit 2.

  Not all attribute data is required for drawing processing. For example, when overwriting drawing with opacity specified, the transparency required for transparency processing and the transparency in the surrounding area change during transparency processing. There is no need for data such as shape values to be generated, and there is no need to hold such data. In general, when superimposing processing is performed between two drawing objects, data of attributes possessed by both of them is often required, and the type of data tends to increase. However, in the drawing process of an image, for example, when the drawing object having data such as transparency is overwritten by the above-described opaque specification, the transparency data is unnecessary. The type of data required may be reduced. In such a case, it can be decided to use a data structure containing a reduced type of data. By taking a data structure that does not include all attribute data in this way, the memory capacity of the drawing data storage unit 2 can be reduced as compared to the case where all the drawing data includes all data.

  The drawing data storage unit 2 holds the drawing data generated by the drawing unit 1 and passes the drawing data held to the drawing unit 1. As described above, since the drawing data only includes the minimum necessary data, the memory capacity can be reduced, and for example, the drawing data can be held without performing processing such as compression. This can contribute to an improvement in processing speed. For example, final drawing data of a predetermined unit such as one page is passed to the processing unit at the subsequent stage.

  An example of the data structure of the drawing data will be described. Here, a case will be described in which edge list data divided for each section having the same drawing result is generated as drawing data for each scan line. FIG. 2 is an explanatory diagram of an example of the data structure of the edge list data. In the edge list data, as shown in FIG. 2, the Y coordinate of the scan line, the start X coordinate and length of the section indicated by the edge list data, and the attribute data in the section are defined as one unit, and this unit set Use to express the image.

  The attribute data field includes data indicating various attributes as described above. For example, color data, an alpha value indicating transparency, a shape value indicating the degree of application of transparency processing in a region where the transparency processing is performed and the peripheral portion, and other tag information necessary for rendering are included. Conventionally, a single data structure including all these data has been used so that any drawing process can be handled. In the present invention, a data structure including data necessary for drawing processing can be applied using a plurality of data structures as described below. Data indicating which data structure is used is also included in the attribute data field.

  FIG. 3 is an explanatory diagram showing an example of a data structure that can be used in the embodiment of the present invention. In the example illustrated in FIG. 3, there are three cases where color data, an alpha value, and a shape value are included as data indicating attributes. Each type of data shown in FIG. 3 is included in the attribute data shown in FIG.

  For color data, for example, monochromatic image data may be monochromatic gradation data, and a color image requires three or four color data. Here, the monochromatic gradation data is expressed as “gray”. In addition, RGB data as three-color data and CMYK data as four-color data are respectively stored as “RGB” and “CMYK”.

  The 12 types of data structures shown in FIG. 3 can be used depending on the combination of the presence / absence of the data of each attribute described above and any one of such color data (including no color data). Type 0 to type 3 show data structures when there is no alpha value and shape value. Type 0 has no color data, Type 1 has monochrome color data as color data, Type 2 has 3 color data as color data, Type 3 has 4 color data as color data Each case is shown.

  Type 16 to type 19 show data structures in the case of having an alpha value but no shape value. As in the case of type 0 to type 3, type 16 has no color data, type 17 has color data of single color gradation data, type 18 has color data of three color data, and type 19 has color. The case where the data is four-color data is shown.

  Type 32 to type 35 show data structures in the case of having both an alpha value and a shape value. Similar to the above-described types, type 32 has no color data, type 33 has color data of single color gradation data, type 34 has color data of three color data, and type 35 has color data of 4. Each case of color data is shown.

  For normal overwriting without superimposing drawing objects (alpha value = 1.0, blend mode = normal, no mask), type 1, type 2, and type 3 are matched to the color space of the output image. The drawing data may be created by selecting and using any one of the data structures. In addition, as a data structure when performing an overlay process between drawing objects, any of types 17 to 19 is used when a mask is not used, and any of types 33 to 35 is used when a mask is used. Drawing data may be created. Note that types 0, 14, and 32 that do not have color data are not normally used and can be used for special purposes.

  As a specific example, 8-bit data for monochromatic gradation data, 24-bit data for 3-color data, 32-bit data for 4-color data, 8-bit alpha value, 8-bit data for shape value Consider the case where a width is required. At this time, the data width of the data portion shown in FIG. 3 is 8 bits for Type 1, 24 bits for Type 2, 32 bits for Type 3, 16 bits for Type 17, 32 bits for Type 18, 40 bits for Type 19 , Type 33 is 16 bits, Type 34 is 40 bits, and Type 34 is 48 bits. When all the attribute data is held as in the prior art, if a color image is handled, each edge list data includes 40-bit or 48-bit data. However, in the present invention, since a data structure that does not hold unnecessary attribute data can be selected, for example, in the case of a monochrome gradation image, the data can be reduced to 8 bits. Therefore, when there are a large number of edge list data that can shorten the data length, the amount of data held in the drawing data storage unit 2 can be greatly reduced.

  When performing a superimposition process between drawing objects, first, edge list data is created for a drawing object to be newly drawn, and the edge list data already drawn and stored in the drawing data storage unit 2 is used. When there is an overlapping part and a non-overlapping part in one edge list data, the edge list data is divided, and the edge list data of the area overlapping the drawing object to be newly drawn New edge list data is generated and stored in the drawing data storage unit 2. The data structure of the newly generated edge list data includes the data structure of the edge list data of the drawing object to be newly drawn and the data structure of the edge list data of the drawing object held in the drawing data storage unit 2. It is determined by processing conditions such as an alpha value, a blend mode, and the presence / absence of a mask.

  FIG. 4 is an explanatory diagram of an example of a relationship between two data structures to be overlaid and a new data structure. In general, the type of attribute data included in the data structure of the new edge list data is the sum of the attribute data included in the data structure of the two edge list data to be superimposed, that is, any of the two edge list data to be superimposed. Can be expressed as a data structure. For example, the data structure of the two edge list data to be superimposed may be a data structure of only color data as in types 1 to 3 shown in FIG. 3, and a data structure of alpha value and color data as in types 17 to 19. For example, the data structure of the new edge list data may be the data structure of the alpha value and the color data as in types 17 to 19 (FIG. 4A). Similarly, if the data structure of only color data as in types 1 to 3 and the data structure of alpha value, shape value, and color data as in types 33 to 35, the data structure of the new edge list data is The data structure of the alpha value, shape value, and color data may be used as in types 33 to 35 (FIG. 4B). Furthermore, if the data structure of the alpha value and color data is as in types 17 to 19 and the data structure of the alpha value, shape value, and color data is as in types 33 to 35, the data structure of the new edge list data is As in types 33 to 35, the data structure of the alpha value, shape value, and color data may be used (FIG. 4C).

  The same applies to color data, and edge list data of the data structure of monochromatic gradation data (gray) shown in types 1, 17, and 33 and the data structure of three color data (RGB) shown in types 2, 18, and 34. In the case of superimposing, the data structure of the new edge list data may be the data structure of three-color data (RGB) shown in types 2, 18, and 34 (FIG. 4D). In the case of superimposing the edge list data on the data structure of monochromatic gradation data (gray) shown in types 1, 17, and 33 and the data structure of four color data (CMYK) shown on types 3, 19, and 35. The data structure of the new edge list data may be the data structure of the four color data (CMYK) shown in types 3, 19, and 35 (FIG. 4F). FIGS. 4D to 4F show only the color data portion, and may include an alpha value or an alpha value and a shape value depending on each type.

  Further, when a mask is provided as a superposition condition, regardless of the data structure of the two edge list data to be superposed, the data structure of the new edge list data can be any of types 33 to 35 including shape values. Good (FIG. 4G). In this example, the alpha value is always included.

  For example, when the alpha value is 0.5, there is no mask, and the blend mode is normal, the data structure of the edge list data of the drawing object to be drawn is type 18, and is held in the drawing data storage unit 2 to be superimposed. When the data structure of the edge list data is type 2, the data structure of the edge list data after superposition is type 18. If the data structure of the edge list data held in the drawing data storage unit 2 is type 33, the data structure of the edge list data after superposition is type 34.

  For the color data described above, edge list data of the data structure of three-color color data (RGB) shown in types 2, 18, and 34 and the data structure of four-color color data (CMYK) shown in types 3, 19, and 35. In the case of superimposing, the data structure of the new edge list data is the data structure of the three color data (RGB) shown in types 2, 18, and 34 (FIG. 4E). That is, the data structure is converted so that the data amount decreases. This is different from the determination of the data structure in the direction in which the general data amount increases as described above. In this example, there is a one-to-one correspondence between RGB, which is three-color data, and CMYK, which is four-color data. Although the conversion from RGB to CMYK is not uniquely determined, the conversion from CMYK to RGB is uniquely determined. Therefore, in order to achieve color matching, it is better to unify with RGB. Therefore, the data structure is selected in such a direction that the amount of data decreases.

  In the drawing process, there are other cases where the data structure can be changed in such a direction as to reduce the amount of data. For example, when overwriting is performed with opaqueness (alpha value = 1.0), even if the edge list data to be superimposed is type 17-19 or type 33-35 having an alpha value or an alpha value and a shape value, it is newly added. Types 1 to 3 can be selected as the edge list data to be generated. Further, in the case of a specific logical operation (or a sequence of logical operations), the data structure may be changed in the direction of reducing the data amount as described above. As described above, in the drawing process, in addition to changing the data structure in the direction of maintaining or increasing the general data amount, the data structure in the direction of decreasing the data amount can be changed.

  As a method for determining the data structure of a newly created drawing object (edge list data) from the data structure of the two drawing objects (edge list data) and the overlay conditions as described above, for example, All conditions may be described, or may be determined by calculation based on priority.

  FIG. 3 described above shows a data structure having three color data, an alpha value, and a shape value as attribute data. However, the data structure shown in FIG. 3 is an example, and the order of data and the type of data to be included are also arbitrary. For other various attributes, the data structure to be held can be selected as necessary. , Can reduce the amount of data.

  In the above-described example, the case where edge list data is generated as drawing data has been described. The drawing data generated by the present invention is not limited to edge list data, and can be applied when generating various types of drawing data, for example, generating planar map data or generating bitmap data. . When data other than bitmap data is generated as drawing data, for example, after a predetermined drawing process for one job, one page, one band, one line, etc. is completed, the data is developed into a bitmap image. Processing will be performed.

It is a block diagram which shows one Embodiment of this invention. It is explanatory drawing of an example of the data structure of edge list data. It is explanatory drawing of an example of the data structure which can be used in one Embodiment of this invention. It is explanatory drawing of an example of the relationship between two data structures to superimpose and a new data structure.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Drawing part, 2 ... Drawing data storage part.

Claims (14)

  An image processing apparatus comprising: drawing means for generating drawing data by performing drawing processing including drawing object superimposing processing according to a drawing command; and storage means for holding the drawing data generated by the drawing means, The means holds the drawing data in one of a plurality of data structures, and when the drawing means performs the overlapping process of the drawing objects, the drawing structure and the data structure of the two drawing objects to be overlaid An image processing apparatus characterized by determining a data structure of drawing data after superposition according to the conditions at the time, and holding the drawing data in the storage means.   The image processing apparatus according to claim 1, wherein the data structure includes color data, color data and transparency, and data structure including color data, transparency, and shape value.   The image processing apparatus according to claim 2, wherein the color data includes any one of single color gradation data, three color data, and four color data.   The drawing means decides to use a data structure that can be represented by a small amount of data when the drawing data after the superposition can be represented by a data structure of less data than the data structure of the drawing object before superposition. The image processing apparatus according to any one of claims 1 to 3, wherein the image processing apparatus includes:   5. The drawing means according to claim 1, wherein the drawing means generates edge list data divided for each section having the same drawing result for each scan line as the drawing data. 6. The image processing apparatus described.   The said drawing means produces | generates the planar map data divided | segmented into the figure for every area | region which becomes the same drawing result as said drawing data, The any one of Claim 1 thru | or 4 characterized by the above-mentioned. Image processing device.   The image processing apparatus according to claim 1, wherein the drawing unit generates bitmap data as the drawing data.   An image processing method for generating drawing data by performing drawing processing including drawing object superimposing processing in accordance with a drawing command by a drawing unit, and for performing drawing processing while holding the generated drawing data in a storage unit. The data takes one of a plurality of data structures, and when the drawing object is overlapped, the drawing data after the overlapping depends on the data structure of the two drawing objects to be overlapped and the conditions for the overlapping. An image processing method, wherein a data structure is determined and drawing data after superposition is held in the storage means.   The image processing method according to claim 8, wherein the data structure includes color data, color data and transparency, and data structure including color data, transparency, and shape value.   The image processing method according to claim 9, wherein the color data includes any one of monochrome color data, three-color data, and four-color data.   When drawing data after superimposition can be expressed with a data structure of data less than the data structure of a drawing object before superposition, it is determined that the data structure that can be expressed with the small data is used. The image processing method according to any one of claims 8 to 10.   The image processing method according to any one of claims 8 to 11, wherein edge list data divided for each section having the same drawing result is generated for each scan line as the drawing data. .   The image processing method according to any one of claims 8 to 11, wherein planar map data divided into graphics for each region that produces the same drawing result is generated as the drawing data.   12. The image processing method according to claim 8, wherein bitmap data is generated as the drawing data.

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