JP2014007595A - Information processing apparatus and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten the time required for data conversion when extracting the difference between an image obtained by reading an image represented by original data in page description language form and an image obtained by reading a manuscript.SOLUTION: An intermediate data generation unit 22 generates intermediate data, from which overlap of a drawing object is removed, from original data in page description language form. A binary processing unit 26 performs binary processing of multi-value bit map data obtained by reading a manuscript, and generates binary bit map data. If a pixel other than the minimum pixel value and the maximum pixel value is not contained in a drawing object represented by a drawing instruction of the intermediate data or a drawing instruction of the original data, a bit map data generation unit 24 generates the binary bit map data directly from the intermediate data. A difference extraction unit 28 compares the binary bit map data generated from the bit map data generation unit 24 with the binary bit map data generated from the binary processing unit 26, and extracts the difference.

Description

  The present invention relates to an information processing apparatus and a program.

  Patent Document 1 includes means for interpreting PDL (page description language), comparing means for comparing a color value of a graphic of a character background with a color value of a character drawn on the graphic unit, and the same In the case of a color value, an image processing apparatus having means for changing a character attribute to a graphic is disclosed.

JP 2009-129342 A

  In order to extract the difference between the image represented by the original data in the page description language format and the read image obtained by reading the document, the present invention always generates binary bitmap data from the original data. An information processing apparatus capable of reducing the time required for data conversion as compared with the case of generating binary bitmap data from the multivalued bitmap data after generating the multivalued bitmap data from the intermediate data, And to obtain a program.

  An information processing apparatus according to a first aspect of the present invention includes first generation means for generating intermediate data from which overlapping of drawing objects is removed from original data in a page description language format, and multi-valued bits obtained by reading a document. A second pixel generating unit that binarizes the map data to generate binary bitmap data, and a drawing object represented by the drawing instruction for the intermediate data or the drawing instruction for the original data. A third generation unit that generates binary bitmap data directly from the intermediate data when a pixel other than a pixel value is not included; and binary bitmap data generated by the second generation unit; Difference extraction means for comparing the binary bitmap data generated by the third generation means and extracting a difference.

  According to a second aspect of the present invention, there is provided the information processing apparatus according to the first aspect, wherein the third generation unit includes a minimum pixel value and a maximum pixel in a drawing object represented by the intermediate data drawing instruction or the original data drawing instruction. When pixels other than the value are included, binarization of the same method as the binarization processing method of the conversion means is performed on the multivalued bitmap data after generating the multivalued bitmap data from the intermediate data Processing may be performed to generate binary bitmap data.

  An information processing apparatus according to a third aspect of the present invention is a first generation means for generating intermediate data from which overlapping of drawing objects is removed from original data in a page description language format, and a multi-valued bit obtained by reading a document A second pixel generating unit that binarizes the map data to generate binary bitmap data, and a drawing object represented by the drawing instruction for the intermediate data or the drawing instruction for the original data. When pixels other than pixel values are included, binarization of the same method as the binarization processing method of the conversion means is performed on the multivalued bitmap data after generating the multivalued bitmap data from the intermediate data A third generation unit configured to generate binary bitmap data by performing processing, a binary bitmap data generated by the second generation unit, and a third generation unit Was then compared with the bit map data of the binary comprises a difference extraction means for extracting difference, the.

  According to a fourth aspect of the present invention, there is provided an information processing apparatus comprising: first generation means for generating intermediate data from which overlapping of drawing objects is removed from original data in a page description language format; and multi-valued bits obtained by reading a document The second generation means for performing binarization processing on the map data to generate binary bitmap data, and a halftone pixel on the drawing object represented by the drawing instruction for the intermediate data or the drawing instruction for the original data If not included, the third generation means for generating binary bitmap data directly from the intermediate data, the binary bitmap data generated by the second generation means, and the third generation means Difference extraction means for extracting the difference by comparing the binary bitmap data.

  The invention according to claim 5 is the first generation means for generating intermediate data from which the overlapping of the drawing objects is removed from the original data in the page description language format, and the multi-value bitmap data obtained by reading the original A second generation means for generating binary bitmap data by performing binarization processing on the drawing object represented by the intermediate data drawing command or the original data drawing command other than the minimum pixel value and the maximum pixel value; A third generation unit that directly generates binary bitmap data from the intermediate data when the pixel is not included, the binary bitmap data generated by the second generation unit, and a third generation unit Is a program for functioning as a difference extraction means for extracting a difference by comparing with binary bitmap data generated by.

  The invention according to claim 6 is the first generation means for generating the intermediate data from which the overlap of the drawing objects is removed from the original data in the page description language format, the multi-value bitmap data obtained by reading the original A second generation means for generating binary bitmap data by performing binarization processing on the drawing object represented by the intermediate data drawing command or the original data drawing command other than the minimum pixel value and the maximum pixel value; When the multi-value bitmap data is generated from the intermediate data, the multi-value bitmap data is subjected to the binarization processing in the same manner as the binarization processing method of the conversion means. Third generation means for generating binary bitmap data, binary bitmap data generated by the second generation means, and generated by the third generation means And binary bitmap data and the difference extracting means for extracting and the difference compared to a program for the function as a.

  According to the first aspect of the present invention, compared to the case where binary bitmap data is generated from multi-valued bitmap data after always generating multi-valued bitmap data from intermediate data, data conversion can be performed. The time required can be shortened.

  According to the second aspect of the present invention, the difference between the image including the pixels other than the minimum pixel value and the maximum pixel value is extracted as compared with the case where binary bitmap data is directly generated from the intermediate data and the difference is extracted. Extraction accuracy does not decrease.

  According to the third aspect of the present invention, the difference between the image including the pixels other than the minimum pixel value and the maximum pixel value is extracted as compared to the case where binary bitmap data is directly generated from the intermediate data and the difference is extracted. Extraction accuracy does not decrease.

  According to the fourth aspect of the present invention, compared to a case where binary bitmap data is generated from multi-value bitmap data after always generating multi-value bitmap data from intermediate data, data conversion can be performed. The time required can be shortened.

  According to the fifth aspect of the present invention, compared to the case of generating binary bitmap data from multi-valued bitmap data after always generating multi-valued bitmap data from intermediate data, data conversion is possible. The time required can be shortened.

  According to the sixth aspect of the present invention, the difference between the image including the pixels other than the minimum pixel value and the maximum pixel value is extracted as compared with the case where the binary bitmap data is directly generated from the intermediate data and the difference is extracted. Extraction accuracy does not decrease.

It is a figure which shows the connection state of information processing apparatus, a terminal device, and a printing apparatus. It is a functional block diagram which showed the structure of the information processing apparatus functionally. It is the figure which represented typically the edge data contained in the intermediate data of an edge list format. (A) is a figure which shows typically the intermediate data of an edge list format, (B) is a figure which shows typically the image represented by the edge list of (A). It is a figure which shows the hardware structural example of information processing apparatus. It is a flowchart which shows the flow of the processing routine performed in the bitmap data generation part of 1st Embodiment. It is a schematic diagram which shows typically the flow from the production | generation of bitmap data to difference extraction. It is a flowchart which shows the flow of the processing routine performed with the bitmap data generation part of 2nd Embodiment.

  Hereinafter, embodiments will be described in detail with reference to the drawings.

  [First Embodiment]

  In the first embodiment, as illustrated in FIG. 1, the information processing apparatus 10 and the terminal apparatuses 12 a, 12 b, and 12 c are connected via a communication unit 16. The communication means 16 may be a public line or a network such as the Internet, a LAN (Local Area Network), or a WAN (Wide Area Network). The communication unit may be a wireless communication unit or a wired communication unit.

  The terminal devices 12a, 12b, and 12c create print data (hereinafter referred to as PDL data) described in a page description language (PDL) for printing data created by an application or the like. To the information processing apparatus 10. The PDL data may be, for example, data in HPGL format or PDF format, or may be postscript or the like. Each of the terminal devices 12a, 12b, and 12c is configured by a computer, and creates PDL data and transmits the PDL data to the information processing device 10.

  A printing device 14 is connected to the information processing device 10, and bitmap data for printing is generated from PDL data received from the terminal devices 12 a, 12 b, and 12 c and transferred to the printing device 14. The information processing apparatus 10 interprets the PDL data, generates intermediate data that is easier to convert to bitmap data than the PDL data, and generates bitmap data from the intermediate data. The intermediate data will be described later.

  The printing apparatus 14 includes a printing unit that prints a print image on a recording medium such as paper. The printing unit of the printing apparatus 14 prints based on the bitmap data received from the information processing apparatus 10.

  Although an example in which the information processing apparatus 10 and the printing apparatus 14 are configured by separate apparatuses will be described here, the information processing apparatus 10 and the printing apparatus 14 may be integrally formed. Although not shown here, the printing device 14 is directly connected to the communication means 16, and the printing device 14 directly receives the PDL data from the terminal devices 12a, 12b, and 12c, and receives the bit from the received PDL data. The map data may be generated and printed. Further, the printing apparatus 14 may receive intermediate data from the information processing apparatus 10, generate bitmap data from the received intermediate data by itself, and print it.

  The printing apparatus 14 of the present embodiment is further provided with a reading unit that reads an image of a document. Bitmap data (hereinafter referred to as read image data) obtained by reading a document with this reading unit is transmitted to the information processing apparatus 10 and held in the information processing apparatus 10. The read image data may be held by the printing device 14.

  In the present embodiment, the reading unit is configured to output bitmap data representing the read image in multiple values greater than two values as read image data.

  The information processing apparatus 10 also includes a difference extraction function for extracting different portions (hereinafter, different portions are referred to as “differences”) between the image represented by the PDL data and the image represented by the read image data.

  For example, a user who operates one of the terminal devices 12a, 12b, and 12c creates data by an application or the like, converts the data into PDL data, causes the printing device 14 to print the data, In some cases, a change such as addition or deletion by a correction pen or the like is added, and a printed matter with the change is read by the printing device 14. The information processing apparatus 10 extracts, for example, a difference between an image represented by the read image data read by the printing apparatus 14 and an image represented by the original PDL data by using the difference extraction function. In the present embodiment, the difference is extracted by comparing bitmap data representing images in binary.

  More specific examples will be described. For example, in a construction inspection site in the construction industry, a document before correction exists as PDL data, but a document after correction of the PDL data may exist only as paper. In this case, the PDL data is once converted into bitmap data, the corrected original image is read by the reading means, and the bitmap data is compared with each other. At this time, since the bitmap data is generally data having a size of A1 to A3, the data size is larger than that of a normal office document. For this reason, when extracting the difference, the multi-valued bitmap data is converted into binary bitmap data. Here, the construction industry inspection is taken as an example, but not only in the construction industry but also in various scenes, the difference is extracted after being converted into binary bitmap data.

  Therefore, in the present embodiment, before the difference extraction, the read image data, which is multi-valued bitmap data, is binarized to generate binary bitmap data, and binary data representing an image of PDL data is generated. Bitmap data is generated.

  FIG. 2 is a functional configuration diagram functionally showing the configuration of the information processing apparatus 10. The information processing apparatus 10 includes a data acquisition unit 20, an intermediate data generation unit 22 as an example of a first generation unit, a bitmap data generation unit 24 as an example of a third generation unit, and a binary as an example of a second generation unit The image processing unit 26, the difference extraction unit 28, the difference image generation unit 30, and the difference display unit 32 are provided.

  The data acquisition unit 20 acquires PDL data and read image data from which a difference is to be extracted.

  The intermediate data generation unit 22 analyzes the PDL data acquired by the data acquisition unit 20 and generates multilevel intermediate data in units of pages. Here, PDL data and intermediate data will be described.

  The PDL data is data in which drawing commands for drawing objects such as fonts, graphics, and images drawn in a page are described, and may include a plurality of drawing commands for the same area. That is, PDL data is data having overlapping (hierarchical structure) of drawing objects.

  For example, when at least some of the drawing objects overlap each other, the pixel value of the drawing object of the uppermost layer is used in the overlapping portion (unless the uppermost drawing object is transparent or translucent) in the final printing stage. Is printed by the printing apparatus 14, and the pixel values of the drawing objects below it are not printed. Therefore, the drawing command included in the PDL data may include a drawing command that does not contribute to the final print image.

  The intermediate data is data from which the overlapping of the drawing objects is removed. For this reason, each of the drawing commands included in the intermediate data contributes to the formation of a printed image that is finally printed. However, since the intermediate data is data at the previous stage of generating bitmap data that holds pixel values in pixel units, its abstraction is lower than PDL data, but has a higher data structure than bitmap data. ing.

  The intermediate data includes, for example, edge list format intermediate data and display list format intermediate data.

  The intermediate data in the edge list format includes a section in which pixels having the same pixel value continue for each line (here, each line in the x-axis direction) and edge data indicating the pixel value (also referred to as a color value) as a drawing command. , Which represents an image. FIG. 3 is a diagram schematically illustrating an example of an edge list corresponding to a line having a y coordinate value of 0 in the xy coordinate system. As shown in FIG. 3, the edge data constituting the edge list is data indicating a drawing object representing a drawing area having a height of 1, and the start point of a section in which the color value color and pixels having the color value color are continuous. (Start x-coordinate) start, end point (end x-coordinate) end of a section in which pixels of the color value color are continuous, and address next indicating the storage destination of the next edge data. If there is no next edge data, NULL is stored in the address next.

  As described above, the edge list format has a list structure in which each edge data for each line is linked by the address next to the next edge data. A data group formed by connecting edge data is called an edge list.

  FIG. 4A is a diagram schematically showing intermediate data when the image of 6 pixels × 6 pixels shown in FIG. 4B is represented in an edge list format. The intermediate data in the edge list format includes edge data for each line and a head address table that stores an address (head address) to the head edge data of each line. For example, in FIG. 4A, the second edge data having a y-coordinate value of 5 means that an area with an x-coordinate value of 1 to 4 is drawn with a color value of 0.

  The intermediate data (not shown) in the display list format is data of a list structure describing the shape of each drawing object and the x and y coordinates of the end after the overlap is removed, and stores the attribute data of the drawing object. A rendering command is constituted by the header portion and the data portion storing data relating to each basic object when the drawing object is decomposed into basic objects such as a rectangle and a line segment.

  The header part includes color value information of the drawing object, supplementary information of the drawing object (identifiers such as characters, graphics, and images), and information indicating the number of basic objects constituting the data part. The data section includes basic object type information and basic object coordinate information. The basic object is an individual figure (object) when a drawing object is divided into a quadrilateral (trapezoid, parallelogram, rectangle, etc.) having at least one set of parallel sides or a line segment.

  The bitmap data generation unit 24 generates binary bitmap data from the intermediate data. In the present embodiment, the bitmap data generation unit 24 is binary depending on whether the pixel value of the drawing object represented by the rendering command of the intermediate data includes a halftone pixel value or not. Different methods for generating bitmap data. Details will be described later.

  The binarization processing unit 26 performs binarization processing for generating binary bitmap data from the read image data. Here, the read image data is binarized by performing a binarization process of a preset method.

  The difference extraction unit 28 compares the binary pit map data acquired from the bitmap data generation unit 24 with the binary bitmap data acquired from the binarization processing unit 26, and extracts the difference. Information indicating the difference (hereinafter referred to as difference information) is output. Here, the corresponding bitmap data are compared with each other to extract a difference. That is, it is obtained by reading binary bitmap data generated from original PDL data and a document on which an image is printed based on the original PDL data or a modified document obtained by correcting the document. The binary image data obtained by binarizing the read image data is compared.

  Based on the difference information from the difference extraction unit 28, the difference image generation unit 30 generates difference image data of the difference image in which the difference is clearly indicated.

  The difference display unit 32 displays a difference image based on the difference image data generated by the difference image generation unit 30.

  An example of the hardware configuration of the information processing apparatus 10 is shown in FIG. The information processing apparatus 10 is realized by the computer 98 shown in FIG. 5 executing a program.

  The computer 98 includes a CPU (Central Processing Unit) 80, a ROM (Read Only Memory) 82, a RAM (Random Access Memory) 84, an HDD (Hard Disk Drive) 86, an operation unit 88, a display unit 90, and a communication IF (Interface). 92 are connected via a bus 94.

  The CPU 80 executes programs stored in the ROM 82 and the HDD 86 and controls the operation of the entire apparatus. The ROM 82 stores programs executed by the CPU 80 (including processing routine programs to be described later), information necessary for the processing of the CPU 80, and the like. Each function of the information processing apparatus 10 described with reference to FIG. 2 is realized by the CPU 80 executing the program. The RAM 84 is used as a work memory or the like.

  The HDD 86 stores a program executed by the CPU 80 and various setting information and data. Read image data and PDL data received from the outside are also stored in the HDD 86.

  Note that the storage medium for storing the program executed by the CPU 80 is not limited to the HDD 86 or the ROM 82. For example, it may be a flexible disk, a DVD disk, a magneto-optical disk, a USB memory (universal serial bus memory) or the like (not shown), or a storage device of another device connected to the communication means 16. .

  The operation unit 88 is composed of, for example, a keyboard, a mouse, and the like, and various information is designated by the user operating the operation unit 88. The display unit 90 includes, for example, a liquid crystal display, an EL display, and the like, and displays various images and messages, a difference image described later, and the like under the control of the CPU 80.

  The communication IF 92 is an interface for communicating with other devices via the communication unit 16.

  Next, the operation of this embodiment will be described with reference to FIGS.

  FIG. 6 is a flowchart showing a flow of a processing routine executed by the bitmap data generation unit 24 of the information processing apparatus 10. This processing routine is executed after the intermediate data is generated by the intermediate data generation unit 22. Further, since the intermediate data is generated in units of pages, when a plurality of pages of data is included in one PDL data, this processing routine is repeated for the number of pages. In the following, a case where the intermediate data is edge list format data will be described as an example.

  In step 100, the bitmap data generation unit 24 determines whether all lines for one page have been inspected. Here, the term “inspection” refers to a process of inspecting whether or not the color value is a value indicating a halftone with reference to edge data as a drawing command constituting each line of the intermediate data. Here, the value indicating halftone means a value other than the minimum pixel value and the maximum pixel value among the values that the color value can take.

  In the present embodiment, the color value specified by the intermediate data rendering command generated by the intermediate data generation unit 22 is expressed by multi-values having more than two gradations, in this case, 256 gradations of 0 or more and 255 or less. It is assumed that Therefore, here, a pixel having a value other than the minimum pixel value 0 (here, white) and the maximum pixel value 255 (here, black), that is, a color value between 1 and 254 is defined as a halftone pixel. Note that 0 may be black and 255 may be white. In addition, although 256 gradations are given here as an example, 16 gradations from 0 to 15 may be used. In this case, pixel values other than 0 and 15 are halftone pixel values.

  If the bitmap data generation unit 24 makes a negative determination in step 100, it selects one uninspected line in step 102.

  In step 104, the bitmap data generation unit 24 determines whether or not all edge data listed in the selected line (hereinafter, edge data is simply referred to as an edge) has been inspected.

  If the bitmap data generation unit 24 makes an affirmative determination in step 104, it returns to step 100.

  If the bitmap data generation unit 24 makes a negative determination in step 104, in step 106, the bitmap data generation unit 24 selects an uninspected edge from the currently selected line.

  In step 108, the bitmap data generation unit 24 refers to the color value of the selected edge and determines whether the color value is 0 or 255.

  If the bitmap data generation unit 24 makes a positive determination in step 108, it returns to step 104.

  If the bitmap data generation unit 24 makes a negative determination in step 108, it determines in step 110 that there is a halftone pixel in the page. In step 112, the bitmap data generation unit 24 converts the intermediate data being processed into multi-value bitmap data (see also FIG. 7A).

  In step 114, the bitmap data generation unit 24 performs binarization processing on the converted multi-valued bitmap data to convert it into binary bitmap data. Here, the binarization processing is performed in the same manner as the binarization processing unit 26 binarizes the read image data (see also FIG. 7B).

  The case where the binarization method is different means that the binarization algorithm itself such as dither or error diffusion is different, the halftone pattern to be used is different, black or white. This is the case when the thresholds for determination are different. When the difference between the two bitmap data is taken, if the binarization processing method is different, the difference is extracted even if there is originally no difference due to the influence. Therefore, the method for binarizing the multi-valued bitmap data generated from the intermediate data is the same as the method for binarizing the read image data.

  In step 108, it may be determined whether the color value of the edge is a halftone color value (in the above example, whether it is 1 or more and 254 or less). In this case, if an affirmative determination is made in step 108, the process proceeds to step 110, and if a negative determination is made, the process returns to step 104.

  More specifically, taking the above-mentioned inspection in the construction industry as an example, if the original document (PDL data image) has a halftone color, the color in the read image is different from the original document. However, depending on the binarization processing method, it may be determined to be the same. In architectural drawings, lines and character portions are often drawn in black and white, but some areas are painted in halftone. In these places, the binarization result differs depending on the binarization processing method and greatly affects the difference extraction result. Therefore, both binarization processing methods are made equal.

  On the other hand, if the bitmap data generation unit 24 determines in step 100 that all the lines for one page have been inspected, the color values of the drawing objects of the intermediate data being processed are 0 and 255. In order to indicate that only the value is present (the page represented by the intermediate data is a binary image), the process proceeds to step 116 and it is determined that there is no halftone pixel.

  Next, the bitmap data generation unit 24 converts the intermediate data being processed into binary bitmap data in step 118. Here, the binary bitmap data is generated directly from the intermediate data without the two-step process of generating the binary bitmap data after generating the multi-value bitmap data (FIG. 7). (See also (C)).

  Specifically, since the color values of each drawing object represented by the intermediate data are all 0 or 255, the color value of each edge data is used (or the color value is replaced with some binary value) Binary bitmap data that holds pixel values in units of pixels is generated.

  In addition to the bitmap data generation unit 24, also on the read image side, the binarization processing unit 26 binarizes the read image data to generate binary bitmap data (FIG. 7D). See also)).

  The difference extraction unit 28 compares the binary bitmap data generated from the intermediate data of the PDL data with the binary bitmap data generated by binarizing the read image data, and extracts a difference ( (See also FIG. 7E). The difference extraction unit 28 supplies information (difference information) indicating the extracted difference to the difference image generation unit 30. The difference image generation unit 30 generates difference image data of an image representing the difference (difference image) based on the difference information.

  The difference display unit 32 displays a difference image based on the difference image data generated by the difference image generation unit 30. Note that the display format of the difference image is not particularly limited as long as the user can grasp the difference. For example, for the difference portion, the partial images of the PDL data and the read image data are superimposed and arranged. Other portions (portions not extracted as differences) may be a difference image in which an image represented by either PDL data or read image data is arranged without being superimposed. Alternatively, the difference portion may be printed using a predetermined color, or may be printed by adding a predetermined mark.

  As described above, in the present embodiment, if the drawing object represented by the intermediate data drawing command does not include any halftone pixels, binary bitmap data is generated directly from the intermediate data. , So as to extract the difference.

  For example, as described above, in an architectural drawing having a large size, it takes time to convert intermediate data into multi-value bitmap data. Furthermore, it takes time to binarize the multi-valued bitmap data, which greatly affects the time until the difference extraction is completed. Therefore, instead of always converting the intermediate data into multi-value bitmap data and then generating binary bitmap data, the intermediate data of the page that does not contain halftone pixels is directly Binary bitmap data is generated from the data to shorten the time required for data conversion.

  As described above, in the difference extraction, the PDL data is the original document, and the read image data to be compared with the image of the document is the printed product of the PDL data itself or a modification of the printed product. Therefore, if the original document PDL data is a data representing a binary image not including halftone pixels, the read image data is also a data representing a black and white binary image except for the corrected portion. Even if binarization is performed, the black pixel is converted as a black pixel, and the white pixel is converted as a white pixel. That is, in the portion corresponding to the original document, there is no variation due to the difference in the binarization method. Therefore, the difference extraction unit 28 extracts the difference without any problem.

  [Second Embodiment]

  In the first embodiment, based on the intermediate data, it is determined whether or not a halftone pixel is included in the drawing object represented by the rendering instruction for the intermediate data, and the page represented by the intermediate data is represented by a halftone. Although an example of determining whether or not a pixel is included has been described, this determination may be performed based on PDL data.

  However, as described in the first embodiment, the PDL data is data from which overlapping of drawing objects is not removed. Therefore, if an exact determination is to be made, it is necessary to confirm the coordinates of the drawing object represented by each drawing command, and to make a determination in consideration of the overlapping of the drawing objects. However, if such a strict determination is made, it takes time as in the case of converting from PDL data to bitmap data.

  Therefore, in this embodiment, without considering the overlap of the drawing objects, if all the pixel values of the drawing objects represented by the drawing commands included in the PDL data are not halftone pixel values, the intermediate data is directly input from the intermediate data. It shall be converted to bitmap data of values. Further, if at least one of the pixel values of the drawing object represented by each of the drawing commands included in the PDL data is a halftone pixel value, it is determined that there is a halftone pixel in the image of the PDL data, and the intermediate data It is assumed that the data is converted into multi-valued bitmap data and then converted into binary bitmap data.

  Note that when determining without considering the overlap in this way, depending on the actual overlapping state of the drawing objects, even if the halftone pixels are not included in the finally obtained image (for example, halftone) Even if a drawing object that does not include halftone pixels is superimposed on a drawing object that includes pixels, it may be determined that halftone pixels are included (hereinafter referred to as this). This is called a misjudgment for convenience.)

  However, for example, many of the architectural drawings described above are composed of lines and characters drawn in black and white, and there are relatively few drawings in halftones. Therefore, for example, the PDL data of 100 pages of architectural drawings includes one or two pages including a rendering command designating a halftone color value. Even if the bitmap data is generated, since the number of pages is very small as a whole, the entire processing time is shortened.

  Hereinafter, the operation of the present embodiment will be described. Since the apparatus configuration is the same as that of the first embodiment, description thereof is omitted.

  FIG. 8 is a flowchart showing the flow of a processing routine executed by the bitmap data generation unit 24 according to this embodiment. The processing routine of this embodiment is executed in units of pages after intermediate data is generated by the intermediate data generation unit 22. Accordingly, when data for a plurality of pages is included in one PDL data, this processing routine is repeated for the number of pages.

  In step 200, the bitmap data generation unit 24 determines whether or not all drawing commands for one page have been inspected. In the present embodiment, the term “inspection” refers to processing for inspecting whether or not the color value is a value indicating a halftone with reference to a drawing command for one page of PDL data.

  If the bitmap data generation unit 24 makes a negative determination in step 200, the bitmap data generation unit 24 selects one uninspected drawing command in step 202.

  In step 204, the bitmap data generation unit 24 determines whether the drawing color value designated by the selected drawing command is 0 or 255.

  If the bitmap data generation unit 24 makes a positive determination in step 204, it returns to step 200.

  If the bitmap data generation unit 24 makes a negative determination in step 204, it determines in step 206 that there are halftone pixels in the page. In step 208, the bitmap data generation unit 24 converts the intermediate data corresponding to the page being processed into multi-value bitmap data.

  In step 210, the bitmap data generation unit 24 performs binarization processing on the converted multi-value bitmap data to convert it into binary bitmap data. As in the first embodiment, the binarization processing is performed in the same manner as the binarization processing unit 26 binarizes the read image data.

  On the other hand, if it is determined in step 200 that all drawing commands for one page have been inspected, the bitmap data generation unit 24 proceeds to step 212 and determines that there is no halftone pixel. The intermediate data corresponding to the page being processed is converted into binary bitmap data.

  Note that the above example is an example. For example, the bitmap data generation unit 24 acquires PDL data before intermediate data is generated by the intermediate data generation unit 22, and performs processing up to the determination of a halftone. Conversion to bitmap data may be performed after the intermediate data is generated by the intermediate data generation unit 22.

  In step 204, it may be determined whether the drawing color value is a halftone color value (in the above example, whether it is 1 or more and 254 or less). In this case, if an affirmative determination is made in step 204, the process proceeds to step 206. If a negative determination is made, the process returns to step 200.

  Further, the information processing apparatus 10 checks the halftone for each color even if the PDL data includes a drawing command of a color drawing object composed of pixel values of each color of YMCK, and 1 in at least one color. If there are any halftone pixels, binarization is performed after converting the intermediate data to multi-valued bitmap data. If there are no halftone pixels, the intermediate data is directly converted into a binary bitmap. You may make it convert into data.

  In the first and second embodiments, the example in which the computer 98 executes the program to realize the information processing apparatus 10 has been described. However, for example, it is realized by a semiconductor integrated circuit, an ASIC (Application Specific Integrated Circuit), or the like. It is also possible to implement each function unit of the information processing apparatus 10 with, for example, an electronic circuit.

DESCRIPTION OF SYMBOLS 10 Information processing apparatus 14 Printing apparatus 20 Data acquisition part 22 Intermediate data generation part 24 Bitmap data generation part 26 Binarization process part 28 Difference extraction part 30 Difference image generation part 32 Difference display part 80 CPU
82 ROM
84 RAM
86 HDD
88 operation unit 90 display unit 98 computer

Claims (6)

(No halftone)
First generation means for generating intermediate data from which overlapping of drawing objects is removed from original data in a page description language format;
Second generation means for generating binary bitmap data by performing binarization processing on multi-value bitmap data obtained by reading a document;
Generate binary bitmap data directly from the intermediate data when the drawing object represented by the intermediate data drawing command or the original data drawing command does not include pixels other than the minimum pixel value and the maximum pixel value. Third generating means for performing,
A difference extraction means for extracting a difference by comparing the binary bitmap data generated by the second generation means with the binary bitmap data generated by the third generation means;
An information processing apparatus comprising: (There is a halftone)
The third generation unit may generate a multi-value from the intermediate data when pixels other than the minimum pixel value and the maximum pixel value are included in the drawing object represented by the intermediate data drawing command or the original data drawing command. 2. The binary bitmap data is generated by performing binarization processing of the same method as the binarization processing method of the conversion unit on the multi-value bitmap data after generating the bitmap data. Information processing device. (Addition 1: There is a halftone)
First generation means for generating intermediate data from which overlapping of drawing objects is removed from original data in a page description language format;
Second generation means for generating binary bitmap data by performing binarization processing on multi-value bitmap data obtained by reading a document;
When a pixel other than the minimum pixel value and the maximum pixel value is included in the rendering object represented by the intermediate data rendering command or the original data rendering command, the multi-value bitmap data is generated from the intermediate data, Third generation means for generating binary bitmap data by performing binarization processing in the same manner as the binarization processing method of the conversion means on the multi-value bitmap data;
A difference extraction means for extracting a difference by comparing the binary bitmap data generated by the second generation means with the binary bitmap data generated by the third generation means;
An information processing apparatus comprising: (Addition 2: No halftone)
First generation means for generating intermediate data from which overlapping of drawing objects is removed from original data in a page description language format;
Second generation means for generating binary bitmap data by performing binarization processing on multi-value bitmap data obtained by reading a document;
A third generation unit that generates binary bitmap data directly from the intermediate data when a halftone pixel is not included in the drawing object represented by the intermediate data drawing command or the original data drawing command; ,
A difference extraction means for extracting a difference by comparing the binary bitmap data generated by the second generation means with the binary bitmap data generated by the third generation means;
An information processing apparatus comprising: (No halftone)
Computer
First generation means for generating intermediate data from which overlapping of drawing objects is removed from original data in a page description language format;
Second generation means for performing binarization processing on multi-valued bitmap data obtained by reading a document to generate binary bitmap data;
When the drawing object represented by the intermediate data drawing command or the original data drawing command does not include pixels other than the minimum pixel value and the maximum pixel value, binary bitmap data is generated directly from the intermediate data. A third extraction unit; and a difference extraction unit that compares the binary bitmap data generated by the second generation unit with the binary bitmap data generated by the third generation unit and extracts a difference;
Program to function as. (Addition 3: There is a halftone)
Computer
First generation means for generating intermediate data from which overlapping of drawing objects is removed from original data in a page description language format;
Second generation means for performing binarization processing on multi-valued bitmap data obtained by reading a document to generate binary bitmap data;
When a pixel other than the minimum pixel value and the maximum pixel value is included in the rendering object represented by the intermediate data rendering command or the original data rendering command, the multi-value bitmap data is generated from the intermediate data, Third generation means for generating binary bitmap data by performing binarization processing in the same manner as the binarization processing method of the conversion means on multi-value bitmap data, and generated by the second generation means A difference extraction unit that compares the binary bitmap data thus generated with the binary bitmap data generated by the third generation unit and extracts a difference;
Program to function as.