JP2006244248A - Image processing device, image processing method, and program for executing image processing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To rapidly carry out image formation in a memory saving manner of PDL data or an electronic document including an alpha blend. <P>SOLUTION: A printer has a process of carrying out post-processing of an alpha blend process at a point of time of intermediate data generation when a process of drawing in a frame memory is unable to carry out the alpha blend process, and providing the intermediate data in a state not including the alpha blend process. It has a generating means for generating the intermediate data by using data used in drawing during intermediate data generation, and a table having a description of alpha blend information, and a configuration efficiently carrying out a removal process by carrying out a process of removing the alpha blend process from the intermediate data on the basis of the table having the description of the alpha blend information. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an information processing apparatus and an information processing method for causing a printer to perform a printing operation.

  Conventionally, a method for speeding up a processing portion to be drawn in a frame memory by using hardware is generally used. Although speeding up effect can be obtained by using hardware, there is a problem that it is difficult to support advanced drawing functions. This problem also occurs when trying to draw at high speed with software. Software related to the drawing process in the frame memory needs to be as simple as possible to speed up, but if you try to support an advanced drawing function, the structure will be complicated and cannot be processed at high speed. . One of the functions is alpha blend processing. If the alpha blend process is not supported, the alpha blend process cannot be performed. Even when the bit depth of the bitmap image is smaller than the bit depth of the alpha blend value (generally, drawing processing in a halftoned state), the alpha blend processing cannot be performed. In order to solve this problem, a drawing unit that draws an input drawing command on a bitmap image, and a drawing method designation unit that performs alpha blend specification (transparency specification) when drawing an input object on a bitmap as the drawing command. In the data processing method of the print control apparatus and the image control apparatus, the alpha value replacement means for replacing the alpha blend designation with area information corresponding to the alpha value, and the drawing command for performing processing according to the area information There is one that converts a drawing command to be converted into a drawing command (see, for example, Patent Document 1).

However, the above prior art is a pseudo alpha blend process, which is different from the rendering result obtained by the original alpha blend process. Therefore, once the intermediate data is generated, the intermediate data is searched and alpha blend processing is performed for the objects that require alpha blending. After the intermediate data has no alpha blending processing, it is rendered in the frame memory. A delivery method can be considered. In this patent, it is assumed that one pixel has a gradation of 8 bits and the alpha value also has a depth of 8 bits. However, the present invention is applicable to any number of bits (for example, 16 bits). Needless to say.
JP2002-7102A (P2002-7102A)

  However, the above-described technique for making the intermediate data in the state without alpha blending requires time to process because it is necessary to determine the overlap between the object for which alpha blending is specified and all the objects existing in the page. There was a problem of end.

  In addition, if you simply save the data with alpha blend specified for each pixel when generating the intermediate data, the amount of information will be enormous and a lot of RAM will be required to store the intermediate data. There was a point.

  SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems, and to enable an alpha blend process without fraud even in an apparatus that does not have a CPU capability or a large amount of memory.

  In a printing apparatus having a process of pre-processing the alpha blend process at the time of generating intermediate data and making the intermediate data not include the alpha blend process when the process of drawing in the frame memory is impossible. In addition, when generating intermediate data, there is a generation means for generating intermediate data using a table describing alpha blend information and data used for drawing, and processing to remove alpha blend processing from the intermediate data based on the table describing alpha blend information Means for efficiently performing the removal process.

  The data used for drawing is grouped into a plurality of objects, and has a means for generating a table for managing the drawing range. In the removal process, the overlapping determination between objects is first performed by determining the overlapping of the drawing range of the group. Processing means for reducing the number of overlap determinations and performing removal processing at high speed is provided.

  Processing that saves memory by having processing means that separates an object with an alpha value specified for each pixel into an image and an alpha value, and converting it into optimal information according to the state of the alpha value and then saving it to intermediate data Have means.

  The means for converting the alpha value is a means for stopping the drawing of the object itself when the value indicates complete transparency (alpha value = 0), and the alpha value when the complete overwriting (alpha value = 255). Is saved, and the image part is replaced with drawing by overwriting the raster operation, and alpha values composed of complete transparency and complete overwriting are determined to be mask processing, and 1-bit mask image and polygon clip information If the type of alpha value used is limited, create a table that assigns each alpha value to a small number of bits, and replace the alpha value with a small number of bits, exceeding the representation of the display or printing device If detailed alpha values are specified, information that can be displayed or displayed on the printing device is thinned out. It has a replacement means.

  Normally, the processing order of objects when generating intermediate data is processed from the object drawn at the bottom, but for documents including alpha blending processing and PDL data, processing from the object drawn at the top And processing means for efficiently removing the alpha blend process.

  According to the present invention, the alpha blend removal process from the intermediate data can be performed at high speed and memory saving, so that when the user displays or prints the document or PDL data including the alpha blend process, drawing at high speed, memory saving, and drawing. Incorrect display or printing results can be obtained.

  A configuration of a laser beam printer suitable for applying this embodiment will be described. Needless to say, the printer to which the present embodiment is applied is not limited to the laser beam printer and the ink jet printer, and may be a printer of another printing method.

  FIG. 1 is a cross-sectional view showing a configuration of a first output device to which the present invention can be applied. For example, a laser beam printer (LBP) is shown.

  In the figure, reference numeral 100 denotes an LBP main body, which inputs and stores print information (character code, etc.), form information, macro instructions, etc. supplied from an externally connected host computer, and responds according to the information. A character pattern, a form pattern, and the like are created, and an image is formed on a recording paper or the like that is a recording medium. Reference numeral 112 denotes an operation panel on which an operation switch and an LED display are arranged. Reference numeral 101 denotes a printer control unit that controls the entire LBP main body 100 and analyzes character information supplied from a host computer. The printer control unit 101 mainly converts character information into a video signal having a corresponding character pattern and outputs the video signal to the laser driver 102. The laser driver 102 is a circuit for driving the semiconductor laser 103, and switches on / off the laser light 104 emitted from the semiconductor laser 103 in accordance with the input video signal. The laser beam 104 is shaken in the left-right direction by the rotary polygon mirror 105 to scan and expose the electrostatic drum 106. As a result, an electrostatic latent image of a character pattern is formed on the electrostatic drum 106. The latent image is developed by a developing unit 107 disposed around the electrostatic drum 106 and then transferred to a recording sheet. A cut sheet is used as the recording paper. The cut sheet recording paper is stored in a paper cassette 108 mounted on the LBP 100, taken into the apparatus by a paper feed roller 111, and supplied to the electrostatic drum 106. Further, the LBP main body 100 is provided with at least one card slot (not shown) so that an optional font card and a control card (emulation card) having a different language system can be connected in addition to the built-in font.

  FIG. 2 is a block diagram illustrating the configuration of the printer control system according to the embodiment of the present invention. Here, a laser beam printer (FIG. 1) will be described as an example. In the figure, reference numeral 200 denotes a host computer, which has a CPU 202 that executes a document with a mixture of figures, images, characters, tables (including spreadsheets) and the like based on a document processing program stored in a program ROM of a ROM 204. The CPU 202 generally controls each device connected to the system device 205. In addition, the various conversion processes shown in FIGS. 7 to 11 and FIGS. 14 to 15 in the present invention are supplied by a medium such as a flexible disk, a CD-ROM, or a DVD-ROM and executed in the same manner.

  The ROM 204 program ROM stores a control program of the CPU 202, the font ROM of the ROM 204 stores font data used in the document processing, and the data ROM of the ROM 204 includes the above-described ROM. Various data used for document processing and the like are stored. A RAM 203 functions as a main memory, work area, and the like for the CPU 202. A keyboard controller (KBC) 206 controls key input from a keyboard 210 or a pointing device (not shown). Reference numeral 207 denotes a CRT controller (CRTC) which controls display on a CRT display (CRT) 211. A memory controller (MC) 208 controls access to an external memory 212 such as a hard disk (HD) or a flexible disk (FD) that stores a boot program, various applications, font data, user files, and edit files. Reference numerals 209 and 226 denote processing units that control I / O between devices, and specific examples include an interface such as IEEE1394. However, any type of interface is possible as long as it is an interface capable of bidirectional communication. In the printer 220, 222 is a printer CPU, which is connected to various devices connected to the system bus 225 based on a control program stored in a program ROM of the ROM 224 or a control program stored in the external memory 231. Access is comprehensively controlled, and an image signal as output information is output to a printing unit (printer engine) 228 connected via the printing unit interface 227. Further, a control program for the CPU 222 is stored in the program ROM of the ROM 224. In the case of a printer without an external memory 2031 such as a hard disk, the data ROM of the ROM 224 stores information used on the host computer. The CPU 222 can communicate with the host computer via the input unit 226, and is configured to notify the host computer 200 of information in the printer. Reference numeral 223 denotes a RAM that functions as a main memory, a work area, and the like for the CPU 222, and is designed so that the memory capacity can be expanded by an optional RAM connected to an expansion port (not shown). The RAM 223 is used for print data storage, output information expansion, environment data storage area, NVRAM, and the like. Access to the external memory 231 such as the hard disk (HD) and the IC card described above is controlled by a memory controller (MC) 228. Reference numeral 230 denotes a switch for operation on the operation panel described above, an LED display device, and the like.

  Further, the number of external memories is not limited to one, but at least one external memory is provided, and in addition to the built-in font, an optional card and a plurality of external memories storing programs for interpreting printer control languages with different language systems can be connected. May be. Further, an NVRAM (not shown) may be provided to store printer mode setting information from the operation panel 230.

  When the process of drawing in the frame memory in the present invention using FIG. 3 and FIG. 4 cannot perform the alpha blend process, the alpha blend process is pre-processed at the time of generating the intermediate data, and the intermediate data includes the alpha blend process. In a printing apparatus that has a process that causes the data to be in a non-existent state, when generating intermediate data, it has generation means for generating intermediate data using a table describing alpha blend information and data used for drawing, and based on the table describing alpha blend information. Next, a method for performing the process of removing the alpha blend process from the intermediate data will be described.

First, the flow of processing for performing alpha blending process removal processing from intermediate data including alpha blending processing to generate intermediate data not including alpha blending processing will be described with reference to FIG. Further, it is assumed that the background of the frame memory is white (RGB (255, 255, 255). 300 is the rendering result of the intermediate data for rendering from 305 to 307 and the intermediate data for alpha blending from 308 to 309. Also, from 307 to 309. Is an intermediate data format including the intermediate data for drawing and the intermediate data for alpha blending suitable for the process of removing the alpha blending processing in the present invention, and the intermediate data for alpha blending is a pointer (here, a pointer to the related intermediate data for drawing) Address) and the actual alpha value are described.No alpha blending processing is specified for 305. When overwriting, the rectangle with the coordinates (1,1) and coordinates (6,6) as the diagonal is RGB Next, since alpha blend value = 128 is designated in 306, drawing is performed while performing alpha blend processing. The blending process is performed by the equation shown at 320. A rectangle whose diagonals are the coordinates (2, 2) and coordinates (6, 6) is R = (128/255) × 128 + (1− (128 / 255)) × 0 = 64
G = (128/255) × 128 + (1− (128/255)) × 0 = 64
B = (128/255) × 128 + (1− (128/255)) × 0 = 64
It becomes.

On the other hand, a portion obtained by excluding the rectangle having the coordinates (2, 2) and the coordinates (6, 6) from the rectangle having the coordinates (2, 2) and the coordinates (7, 7) as the diagonal is R = (128 / 255) × 128 + (1− (128/255)) × 255 = 192
G = (128/255) × 128 + (1− (128/255)) × 255 = 192
B = (128/255) × 128 + (1− (128/255)) × 255 = 192
It becomes.

Next, since the alpha blend process is required again for 307 and alpha value = 128 is designated, the rectangle whose coordinates are (3,3) and coordinates (5,5) is R = (128/255) × 255+ (1- (128/255)) × 64 = 160
G = (128/255) × 255 + (1− (128/255)) × 64 = 160
B = (128/255) × 255 + (1− (128/255)) × 64 = 160
It becomes.

  Therefore, the portion indicated by 301 is RGB (0,0,0), the portion indicated by 302 is RGB (192,192,192), the portion indicated by 303 is RGB (64,64,64), and the portion indicated by 304 is RGB ( 160,160,160).

  The flow of applying the above processing to intermediate data will be described using 305 to 317. First, focus on 306 objects that require alpha blending. An object that is drawn before 306 (lower layer in the drawing layer) and that overlaps the drawing area of 306 is searched. Since 305 corresponds, the overlapping area is obtained. Since the overlapping area is a rectangle having a width (4, 4) with coordinates (2, 2) at the upper left, 310 is generated by cutting out the area from 305, and 312 is also generated from 307 in the same manner. The overlapped area is generated as 311 and the color of the area is RGB (128, 128, 128) and RGB (0, 0, 0) which is RGB (64, 64, 64) obtained by performing alpha blend processing with an alpha value = 128. Since there is no object before this, 311 performs alpha blend processing with the frame memory background. Therefore, since RGB (128, 128, 128) and RGB (255, 255, 255) are alpha blended with alpha value = 255, RGB (192, 192, 192) is written in 311. The state in which the processing for 306 is completed is 310 to 311. At this point, 307 has not processed anything, so the content has not changed from 313. Next, since it is 313 that requires alpha blending processing, an object having overlapping drawing areas is searched under the same conditions as in 307. Since the drawing area 311 overlaps, 315 is generated by cutting out the overlapping area. Since the area overlapped with 313 is completely identical, only 317 is generated. Since the color of the region 317 is a color obtained by alpha blending RGB (255, 255, 255) and RGB (64, 64, 64) with an alpha value = 128, RGB (160, 160, 160) is written in 317. Since there is no area that has not been processed in 313, the process ends. Since 310 and 312 do not overlap with 313, the contents of 314 and 316 do not change. There is no alpha blending process for the intermediate data in the states 314 to 317. Even if this intermediate data is completely overwritten, the same result as 300 can be obtained. Therefore, this intermediate data becomes intermediate data from which the alpha blending process for obtaining a normal drawing is removed even if the process of drawing in the frame memory does not have the ability to perform the alpha blending process.

  Next, the reason why it is possible to shorten the time of the alpha blend process removal process by having the intermediate data for alpha blend will be described with reference to FIG. 400 is an image to be finally composed. 400 includes objects 301 to 305. Among them, 302 and 305 require alpha blend processing. Therefore, intermediate data 311 to 315 for drawing corresponding to the objects 301 to 305 are generated as the intermediate data. Further, alpha blending intermediate data 316 and 317 are respectively generated in 302 (or 312) and 305 (or 315) that require alpha blend processing. 321 is the object search order when the intermediate data for alpha blending is not generated. However, when there is no intermediate data for alpha blending, it is necessary to search for an object that needs to be alpha blended first. The search for the part surrounded by will occur. Conversely, in the search order having the intermediate data for alpha blending, it is only necessary to refer to the intermediate data for alpha blending, so that the search can be omitted and the processing can be performed at high speed. Although there is an impression that there is no difference because the number of objects is small in this implementation, it is normal that there are about 20,000 to 30,000 objects per page in the actual drawing processing, and there is a big difference in display and printing speed Will come out.

  Next, a method for realizing memory saving by reducing the size of the intermediate data when generating the intermediate data from the document including the alpha blend process or the PDL data will be described with reference to FIGS.

  As shown in 501, there are a method of specifying an alpha value for each pixel and a method of specifying an alpha value for each object (the same alpha value is used for all pixels). When an alpha value is designated for each pixel, it is divided into an actual color value 502 and an alpha value 503 for management. In this case, the intermediate data for alpha blending uses the format of the transmission data 504 as an image, and describes an address 505 where the divided image-like alpha value 506 is stored. If an alpha value is specified for each object, the actual alpha value (128 here) is written in 508 with the transparent data format as the alpha value in 507. 110 is an example of a separated image-like alpha value. According to the above processing, the data is stored as 111 to 113. However, when the contents of 110 are viewed, the same alpha value is designated for all pixels, which is the same as the alpha value is designated for each object. Documents including alpha blend processing in a memory-saving manner because memory for saving the image-like alpha values of 113 is not required by saving the alpha value for each object as shown in 114 to 115. Alternatively, intermediate data of PDL data can be generated. Whether 110 is in a state where an alpha value is designated for each object can be determined at the time of separation processing from 101 to 103, thereby speeding up the processing. Further, the processing time can be ignored by performing the separation processing simultaneously with the processing for matching the color space for each apparatus.

  FIG. 6 illustrates some of the contents that are the basis for the replacement in the method of replacing the image-like alpha value described with reference to FIG. 4 with simple data according to the contents.

  Reference numeral 601 denotes a case where the alpha value is the same for all pixels and the alpha value is 0 or 255. If all are 0, it is the same as not drawing, so neither drawing intermediate data nor alpha blending intermediate data is created. If the alpha value is 255, it is completely overwritten, so only the intermediate data for drawing is created, and the intermediate data for alpha blending is not created. As a result, drawing is performed by overwriting.

  If the image-like alpha value is composed of only 0 and 255, 602 is equivalent to the mask process. In this case, when the shape forming 255 is simple, it is stored as an edge list (polygon information) as shown at 605, and when the shape is complicated, it is stored as a 1-bit mask image. Reference numeral 603 denotes an edge list or mask information, and reference numeral 604 denotes an edge list or a pointer to a 1-bit mask image.

  Reference numeral 606 describes an actual 8-bit alpha value, but there is an actual apparatus that does not have the ability to express a fine difference in alpha value as a display or printing ability. In this case, 607 is an example of a device that can express only 64 gradations, but is stored in a state of being thinned to 4 bits. At that time, the transparent data format is an image of 4 bits at 608, and a pointer to data expressed as an image and ALPHA is expressed by 4 bits at 609.

  FIG. 7 is a diagram showing a state in which the search procedure is further reduced and the speed is measured by managing the drawing intermediate data in groups for each object having a drawing position close to each other. An image 701 is finally formed. The objects used for formation are managed for each object in which the drawing position and drawing range are gathered as indicated by 702. In this case, the drawing intermediate data is composed of the above-described drawing intermediate data 703 and group range information 704. The group range information is a rectangle indicated by a broken line in the diagram 702, and includes start point information and a height. When the intermediate data for alpha blending 705 is processed, the overlap with the object is not judged, but is first compared with the group range information 704. Only when the group range information and the drawing range overlap, detailed overlap determination with the objects belonging to the group is performed. The example shown in FIG. 7 is the most preferable example, and since there is no overlap with the group range information, the overlap determination with the object is not performed, and only the overlap comparison with the group range information (in this case, four times) is performed. It will be good. This makes it possible to perform alpha blend removal processing with intermediate data at high speed. In this embodiment, the objects are grouped in an arbitrary range, but may be managed in a fixed area such as a band.

  FIG. 8 is a diagram showing a state in which alpha blend removal processing with intermediate data is speeded up by processing a document or an object of PDL data including alpha blend processing in reverse order.

  Reference numeral 801 denotes an image to be finally formed, and the order of objects included in the image is lined up from what is usually drawn in the lowest layer in the drawing layer as indicated by 802, and processing is usually performed in that order. is there. When generating intermediate data from a document or PDL data including an alpha blend process, the alpha blend removal process with the intermediate data can be made more efficient by processing from what is drawn on the top layer. By generating and placing the intermediate data for 804 alpha blending first, the overlap determination of the drawing range with each object can be performed at the time of generating each object, and there is no need to search again after generating the intermediate data. It is.

  Note that the printing apparatus 812 does not have sufficient memory in the apparatus, and can process only in the order in which data is sent. In such a case, a method may be considered in which the object order is changed in the transmission source PC or the like 811 and then transmitted to the printing apparatus.

It is sectional drawing of a printing apparatus. It is a block block diagram of a printing apparatus. Illustrates alpha blend removal processing with intermediate data. The search processing efficiency improvement at the time of alpha blend removal processing is illustrated. Illustrates intermediate data generation and data reduction for alpha blending. Shows variations of data reduction. Shows the efficiency of removal processing by having group information. Illustrate efficiency gains by processing objects in reverse order.

Claims (9)

  In a printing apparatus having a process of pre-processing the alpha blend process at the time of generating intermediate data and making the intermediate data not include the alpha blend process when the process of drawing in the frame memory is impossible. In addition, when generating intermediate data, there is a generation means for generating intermediate data using a table describing alpha blend information and data used for drawing, and processing to remove alpha blend processing from the intermediate data based on the table describing alpha blend information Means for efficiently performing the removal process. Processing that saves memory by having processing means that separates an object with an alpha value specified for each pixel into an image and an alpha value, and converting it into optimal information according to the state of the alpha value and then saving it to intermediate data An image processing apparatus comprising: means.   The intermediate data according to claim 1 includes means for generating a table for managing a drawing range of data used for drawing in a group of a plurality of objects, and determining whether the objects overlap in the removal process is first drawn in the group. By having overlap determination on the range, processing means for reducing the number of overlap determinations and performing removal processing at high speed is provided.   The means for converting the alpha value described in claim 1 is a means for stopping the drawing of the object itself when the value indicates complete transparency (alpha value = 0).   The means for converting the alpha value according to claim 1 is a means for canceling the storage of the alpha value and replacing the image portion with drawing by overwriting the raster operation when complete overwrite (alpha value = 255). It is characterized by.   The means for converting the alpha value according to claim 1 is a means for judging that the alpha value constituted by complete transparency and complete overwrite is mask processing and replacing it with 1-bit mask image or polygon clip information. It is characterized by.   According to the first aspect of the present invention, when the type of alpha value used is limited, the means for converting to alpha creates a table that assigns each alpha value to a small number of bits and replaces the alpha value with a small number of bits. It is a means.   The means for converting the alpha value according to claim 1 is a replacement means for thinning out information that can be expressed by the display or printing apparatus when a detailed alpha value exceeding the display or expression of the printing apparatus is designated. It is characterized by that.   The processing order of objects when generating intermediate data is processed from the object drawn at the bottom, but for documents and PDL data that include alpha blending processing, processing from the object drawn at the top is efficient. An image processing apparatus characterized by comprising a process for performing an alpha blend process removal process.   An image processing system using the image processing apparatus according to claim 1.

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