JP4075546B2 - Image processing device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a printing apparatus that generates raster data from document data provided in a page description language and performs printing.
[0002]
[Prior art]
Conventionally, document data created by a host computer such as a personal computer or a digital camera has various types of document components such as characters, images, and tables. When the printer receives document data from a personal computer or the like, it generates raster data for printing as one image for each page without considering such distinction of document components. The printer performs processing such as resolution conversion, color conversion, and halftone processing on the print data to generate print data (so-called row data) and perform printing.
[0003]
[Patent Document 1]
JP 2000-354165 A
[0004]
[Problems to be solved by the invention]
However, if raster data is generated by a conventional method, it has not been possible to perform processing that makes use of the characteristics of each document component. For example, character data in one image is generally smaller in data size and easier to handle than image data, but since it was handled as one document together with image data, compression of only character data, etc. The process could not be applied.
[0005]
The present invention has been made to solve the above-described problems, and an object thereof is to provide a technique for generating print data by utilizing the characteristics of each document component.
[0006]
[Means for solving the problems and their functions and effects]
In order to solve the above problems, an image processing apparatus according to the present invention generates character raster data and image raster data separately and combines them, and a character generation unit that generates character raster data. A character plane for storing the character raster data, an image generation unit for generating the image raster data, an image plane for storing the generated image raster data, and an image composition unit. In the image composition unit, the priority of image composition is set in advance so that the character plane has priority over the image plane.
[0007]
Here, “raster data” in the present specification means bitmap data developed so as to be raster-scannable.
[0008]
Since the character plane is set in advance so that the image plane is prioritized over the image plane, the tone and color of the dot where the character and the image overlap can be determined with priority on the character. That is, in a portion where a character and an image overlap, priority is given to the gradation and color of the character, the gradation and color of the image can be ignored, and image composition can be easily performed.
[0009]
Specifically, each pixel constituting the character plane can set any one of a plurality of values represented by n bits, and any one of the plurality of values can be set as a transparent color. Each pixel constituting the image plane can set a plurality of colors expressed by m bits, and can be configured to have no information for setting a transmission coefficient.
[0010]
Each pixel of the character plane (also referred to as a character pixel) can be described with a relatively small amount of data, such as 2 bits, 3 bits, 4 bits, etc., and any one value is set for each pixel. be able to. If n = 1, each pixel of the character plane takes a value of “0” or “1”.
[0011]
Then, either “0” or “1” is set in advance as a transparent color (here, for convenience of explanation, “1” is a specific color and “0” is a transparent color). As a result, it is possible to generate a character plane in which the character portion is displayed in a specific color and the remaining portion is transparent. When this character plane is overlaid on the image plane, the character color is displayed for pixels for which “1” is set in the character plane, regardless of the value of the corresponding image plane pixel (also referred to as an image pixel).
[0012]
On the other hand, since the pixel in which “0” is set in the character plane is a transparent color, the color of the image pixel expressed by m bits is displayed as it is. In the part where the character and the image overlap, the character is prioritized and the character pixel is displayed. In the other part, the image pixel is displayed as it is, so there is no room for considering the transparency of the image pixel. Therefore, it is not necessary for the image raster data to include attribute information that defines the transmission coefficient, and the data size of the image data can be reduced.
[0013]
In one aspect of the present invention, there is further provided a character color control table that associates an arbitrary character color with other values excluding a value to which a transparent color is assigned among a plurality of values, and the character set in the character color control table The color of each pixel of the character plane is determined by the color.
[0014]
For example, when a pixel of a character plane takes a value other than the value set for the transparent color, it can be displayed in an arbitrary color set in advance by referring to the character color control table with that value. Specifically, for example, if the character color “000000” is assigned to the value “1” of the character pixel, the pixel can be displayed in black, and if the character color “F00000” is assigned, the value “1” is displayed. Can be displayed in red.
[0015]
In one aspect of the present invention, the data processing device further includes a first data processing device and a second data processing device, the first data processing device including a character generation unit and an image generation unit, and a second data processing unit. The apparatus includes an image composition unit. The character plane and the image plane are stored in a buffer memory shared by the first data processing apparatus and the second data processing apparatus, and raster data is transferred via the buffer memory.
[0016]
A typical example of the first and second data processing devices is a CPU. However, the first and second data processing devices are not limited to a single CPU, and may include a ROM, a RAM, an input / output port, and the like.
[0017]
The first data processing device generates character raster data and image raster data, and stores each raster data in each plane of the buffer memory. The second data processing apparatus reads the data of each plane from the buffer memory and synthesizes character raster data and image raster data. In this way, by distributing the functions among the data processing devices, it is possible to prevent an excessive burden on any one of the data processing devices.
[0018]
In addition, a plurality of shared buffer areas may be provided in the buffer memory, and the shared buffer areas may be switched and used.
[0019]
In one aspect of the present invention, the first data processing device and the second data processing device share and execute a plurality of data processing functions to generate print image data based on the input print data. In the printer to be printed by the print engine, the first data processing device includes at least a character generation function for converting character data in the print data into character raster data and an image for converting image data in the print data into image raster data. The second data processing device executes the generation function, and combines the raster function that combines at least the character raster data and the image raster data, the color conversion function that performs color conversion on the combined raster data, and the color-converted raster data. Executes halftoning function for halftoning and engine control function for controlling print engine The first data processing device and the second data processing device exchange data via a shared buffer memory, and each pixel constituting the character plane has a plurality of n bits. Any one of the values can be set, and any one of the plurality of values is set as a transparent color, and each pixel constituting the image plane has a plurality of colors expressed by m bits. Can be set, and the information for setting the transmission coefficient is not included.
[0020]
The print data is created in a high-level print language such as Postscript or XHTML-print (print command written in an extensible hypertext markup language). Therefore, high-level data processing is required to interpret each print command of print data and generate raster data. On the other hand, converting raster data into image data for printing is a mechanical process that only requires color conversion of each already formed dot pattern, halftoning process, or the like. Therefore, the first data processing apparatus executes the processes up to raster data generation, and the second data processing apparatus performs processing after the raster data generation, thereby distributing the load on each data processing apparatus.
[0021]
Specifically, data processing functions that require advanced processing include a character generation function that converts character data in print data into character raster data, and an image generation function that converts image data in print data into image raster data. Other data processing functions include a composition function for combining character raster data and image raster data, a color conversion function for color conversion of the combined raster data, and a color converted raster. A halftoning function for halftoning data and an engine control function for controlling the print engine can be included.
[0022]
Then, the first data processing device and the second data processing device exchange data via a buffer memory shared by the first data processing device and the second data processing device. That is, data communication is not performed using a parallel interface, a serial interface, or the like, but raster data is transferred via a buffer memory shared by both data processing apparatuses. Here, the raster data means bitmap data and does not have to be band-shaped data. Therefore, for example, the present invention can be applied not only to a serial printer such as an inkjet printer but also to a page printer such as a laser printer.
[0023]
According to another aspect, in an image processing apparatus that separately generates and combines first raster data and second raster data, a first generation unit that generates first raster data, A first plane for storing the generated first raster data, a second generation unit for generating the second raster data, a second plane for storing the generated second raster data, An image processing apparatus is provided that includes an image composition unit in which a priority of image composition is set in advance so that a plane has priority over a second plane.
[0024]
For example, low-tone image raster data that can represent 256 colors is used as the first raster data, and high-tone image raster data that can be represented by 8-bit RGB colors as the second raster data. It is also possible to superimpose image raster data having a small number in preference to image raster data having a large number of colors.
[0025]
The present invention can also be understood as a program for controlling an image processing method and an image processing apparatus. For example, the program can be distributed by being stored in various recording media such as a CD-ROM, a magneto-optical disk, and a memory, and can also be distributed via a communication network.
[0026]
The generation apparatus of the present invention that solves at least a part of the above problems is as follows.
A generation device for generating raster data from document data,
An input unit for inputting target document data which is the document data including a plurality of different document components;
A dividing unit that divides the target document data according to document components;
A raster data creation unit for creating raster data corresponding to the divided document components;
An output unit for outputting a plurality of raster data created by the raster data creation unit;
It is characterized by providing.
[0027]
According to the generation apparatus of the present invention, it is possible to create raster data for each document component. Since the document component includes characters, images, tables, and the like, for example, character-only raster data and image-only raster data can be created from document data consisting of characters and images. Such raster data for each document component can be subjected to processing suitable for the document component.
[0028]
Further, the dividing unit may not divide the document data for each document constituent element. For example, document data composed of characters, images, and tables may be divided into only characters, images, and tables to create respective raster data. That is, raster data including only characters and raster data including an image and a table may be created.
[0029]
Such a generation device may be built in a device that generates document data, may be built in a device that outputs document data, or may be externally attached. Examples of devices that generate document data include computer devices such as personal computers and video game machines, and video output devices such as digital cameras, DVD players, video decks, video cameras, televisions, and set-top boxes. Furthermore, BS / CS / terrestrial digital broadcast compatible televisions and tuners are devices that generate document data. As an apparatus that outputs document data, for example, a printer, a personal computer, and the like exist.
[0030]
The document data includes data described in a markup language such as XML, HTML, XHTML, and the like.
[0031]
A plurality of raster data created by the raster data creation unit, each comprising a conversion unit for performing a conversion process to reduce the data size of the raster data;
The output unit may be configured to output a plurality of raster data converted by the conversion unit.
[0032]
By providing such a conversion unit, raster data having a reduced size can be output. In particular, raster data composed only of characters can be easily reduced in data size.
[0033]
The conversion process may be a color expression method conversion and / or compression conversion.
[0034]
If the color expression method is converted or compression-converted, the raster data can be output with a reduced data size. Since character data is often expressed in one color, it is effective to convert the color expression method.
[0035]
The document component may be of two types: characters and images.
[0036]
The document data is mainly composed of two types of document components, that is, characters and images. These two types of data are easy to distinguish and are easily divided into document components.
[0037]
The raster data creation unit may create each raster data with different resolutions.
[0038]
By doing so, it is possible to create raster data with a resolution corresponding to the characteristics of each document component.
[0039]
On the other hand, the printing apparatus of the present invention that solves at least a part of the above problems is as follows.
A printing apparatus that generates print data from raster data,
A raster data input unit for inputting a plurality of raster data to be printed on the same page;
A gradation determining unit that determines gradation values of raster data for printing for each pixel based on gradation values in each pixel of a plurality of raster data input by the raster data input unit;
A print data creation unit that creates print data by performing predetermined processing based on the determined gradation value;
A print data output unit for outputting the print data created by the print data creation unit;
It is characterized by providing.
[0040]
According to the printing apparatus of the present invention, it is possible to combine one image from a plurality of raster data as print data while performing predetermined processing at high speed with a small memory. As a method for determining the gradation value, any one of the plurality of raster data may be selected. At the time of selection, it is preferable that a priority order is determined for each document component. Further, the gradation value may be determined by performing an operation based on each gradation value (such as obtaining an average). In that case, you may consider a weight.
[0041]
Moreover, the printing apparatus of the present invention that solves at least a part of the above problems is as follows.
A printing apparatus that generates print data from raster data,
A raster data input unit for inputting a plurality of raster data output by the output unit;
A raster data processing unit that individually performs predetermined processing on a plurality of raster data input by the raster data input unit;
A print data generation unit that generates print data for each pixel based on a gradation value in each pixel after the processing is performed;
A print data output unit for outputting the print data generated by the print data generation unit;
You may comprise as what is provided.
[0042]
According to the printing apparatus of the present invention, it is possible to synthesize one image after performing predetermined processing individually on a plurality of raster data. Since composition is performed after processing, the image quality of each document component can be improved.
[0043]
The predetermined process performed by the print data creation unit includes at least a halftone process, a color conversion process for converting color data described in the RGB color system to color data in the CMY color system, and a resolution conversion process. It may be one.
[0044]
By appropriately performing these processes, print data can be created.
[0045]
A processing unit that individually performs predetermined preprocessing for unifying the data format for a plurality of raster data input by the raster data input unit may be provided.
[0046]
In this way, print data can be created even if arbitrary processing is performed on the input raster data.
[0047]
The predetermined preprocessing performed by the processing unit may be at least one of conversion of a color expression method, cancellation of compression, and resolution conversion for unifying the resolution of a plurality of raster data.
[0048]
In this way, print data can be created even if the color representation method of the input raster data is converted or compression-converted. Further, when the resolution is not uniform among a plurality of raster data, the resolution can be uniformed.
[0049]
The print data generation unit may generate the print data while converting the resolution.
[0050]
By doing so, it is possible to convert the resolution when combining a plurality of raster data into one image.
[0051]
The present invention can be configured in various modes such as a raster data generation method, print data generation method, and printing method, in addition to the above-described generation device and printing device. You may comprise as a computer program for performing the production | generation of raster data, the production | generation of print data, and control of a printing apparatus by computer. Moreover, you may comprise as a computer-readable recording medium which recorded such a computer program. Here, as a recording medium, a flexible disk, a CD-ROM, a magneto-optical disk, a DVD, an IC card, a ROM cartridge, a punch card, a printed matter on which a code such as a barcode is printed, a computer internal storage device (RAM or ROM) Etc.) and various media that can be read by a computer, such as an external storage device.
[0052]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in the following items.
A. First embodiment:
A1. overall structure:
A2. Function block:
A3. Raster data:
A4. processing:
A5. effect:
B. Second embodiment:
B1. processing:
B2. effect:
C. Variation:
[0053]
A. First embodiment:
A1. overall structure:
FIG. 1 is an overall configuration diagram of an embodiment of the present invention. The computer 20 generates document data in a printing language such as XHTML-print, for example. Examples of the computer 20 include a set top box (STB) for receiving a personal computer, a digital camera, a portable information terminal, a mobile phone, a satellite broadcast, etc. and displaying them on a display device.
[0054]
The printer 25 is configured as a so-called direct printable printer that can perform printing based on document data input from a peripheral device without using a personal computer. As will be described later, the printer 25 includes a main CPU that functions as a generation device, a sub CPU that functions as a printing device, a shared buffer, and a print engine.
[0055]
A2. Function block:
FIG. 2 is a functional block diagram of the printer 25. The printer 25 includes a generation device 30, a print engine 35, and a shared buffer 40. The generation device 30 includes an input unit 45, a division unit 50, a raster data creation unit 55, a conversion unit 57, a compression unit 59, and a communication unit 60.
[0056]
The input unit 45 receives document data from the computer 20. The dividing unit 50 analyzes the command of the document data received by the input unit 45 and divides it into a command for displaying characters and a command for displaying images. When the document data is described in XHTML, XML (Extensible Markup Language) or the like, the dividing unit 50 has a function of interpreting XHTML or XML.
[0057]
The raster data creation unit 55 calls character raster data (hereinafter referred to as character raster data) from a command for displaying characters, and image raster data (hereinafter referred to as image raster data) from a command for displaying images. ). When creating character raster data from a command for displaying characters, a font memory or the like is referred to. Image raster data is created by placing a designated image at a designated location in accordance with a command for displaying the image.
[0058]
The conversion unit 57 converts the color rendering method of the character raster data. The compression unit 59 compresses image raster data and character raster data. The communication unit 60 communicates with the print engine 35 and the shared buffer 40 such as writing the created image raster data and character raster data in a predetermined area of the shared buffer 40 and transmitting a print command to the print engine 35.
[0059]
The print engine 35 includes a command analysis unit 63, a raster data input unit 65, a decompression unit 70, a resolution conversion unit 73, a selection unit 75, a format conversion unit 77, a print data creation unit 80, and a print data output unit 85. . The print data creation unit 80 includes a color conversion unit 81, an H / T processing unit 82, and an interlace processing unit 83.
[0060]
The command analysis unit 63 interprets the print command input from the generation device 30. Examples of the command interpreted here include the number of copies to be printed, enlargement / reduction designation, and the like. The raster data input unit 65 inputs a plurality of raster data stored by the generation device 30 from the shared buffer 40.
[0061]
The decompression unit 70 decompresses the compressed raster data. The resolution conversion unit 73 converts the resolution. The selection unit 75 selects either image raster data or character raster data for each pixel. The format conversion unit 77 restores the color expression method converted by the conversion unit 57.
[0062]
The print data creation unit 80 creates print data from raster data. That is, the color conversion unit 81 converts colors described in the RGB color system or the like into CMY color system data, and the H / T processing unit 82 converts multi-gradation data into area gradations, and performs interlace processing. Unit 83 performs conversion for outputting print data in an interlaced manner. The print data output unit 85 outputs the print data to the printer engine.
[0063]
The shared buffer 40 is a memory shared by the generation device 30 and the print engine 35. When the generation device 30 writes the character raster data and the image raster data in a predetermined area of the shared buffer 40, the print engine 35 reads out the written character raster data and the image raster data, and processes both the raster data. .
[0064]
A3. Raster data:
FIG. 3 is an explanatory diagram showing the document 87 represented by the document data to be processed. The document 87 is formed by superimposing characters such as “EP” and “FH” and a background image. Such a document 87 is divided into predetermined widths, and one of them is called one band. The band represents a processing unit and can be arbitrarily set according to the buffer size and the processing speed. In this embodiment, processing is performed in band units in order to speed up processing.
[0065]
FIG. 4 is an explanatory diagram showing 1-band character raster data 90 of the document 87 of FIG. Since the character raster data 90 is a single color, the color representation method is converted by the conversion unit 57 so that each dot takes a value of “0” or “1”. The dot having the value “1” is set so as to represent any one color designated by the character color control table T1, for example, “black”. The dot with the value “0” is set as “transparent color”.
[0066]
On the other hand, FIG. 5 is an explanatory diagram showing 1-band image raster data 95 of the document 87 of FIG. The image raster data 95 is configured such that each dot takes a gradation value of 24 bits in total, 8 bits for each of RGB.
[0067]
FIG. 6 is a schematic diagram showing the configuration of the shared buffer 40. As shown in FIG. 6, the shared buffer 40 is provided with two buffers, an input buffer B0 and an input buffer B1. The sizes of the input buffers B0 and B1 are determined and secured for each print job. Then, a double buffer method is employed in which raster data is read from the other buffer and processed while raster data is being written to one buffer.
[0068]
The input buffer B0 is provided with a character plane CP0 that is a buffer for storing the character raster data 90 and an image plane PP0 that is a buffer for storing the image raster data 95. The character plane CP0 and the image plane PP0 have a predetermined size determined by the printing width and band height. The same applies to the input buffer B1.
[0069]
A4. processing:
FIG. 7 is a flowchart showing processing from generation of print data from document data to output. The flowchart on the left side is a flowchart of the generation apparatus 30, and the flowchart on the right side is a flowchart of the print engine 35. The input unit 45 of the generation device 30 inputs document data from the computer 20 (step S27). The dividing unit 50 analyzes the command of the document data input by the input unit 45 and divides the command into a command for displaying characters and a command for displaying images (step S29).
[0070]
The raster data creating unit 55 creates the character raster data 90 from the command for displaying characters and the image raster data 95 from the command for displaying images divided by the dividing unit 50 (step S30). At this time, the resolution of the character raster data 90 is created at 720 dpi, and the resolution of the image raster data 95 is created at 360 dpi.
[0071]
The conversion unit 57 converts the color rendering method of the character raster data 90 so that the data size is reduced (step S32). The compression unit 59 compresses the character raster data 90 and the image raster data 95 (step S34). The communication unit 60 outputs the image raster data 95 and the character raster data 90 created by the raster data creation unit 55 to the shared buffer 40 (step S35), and transmits a print command to the print engine 35 (step S37).
[0072]
The command analysis unit 63 receives a print command from the generation device 30 (step S40). The raster data input unit 65 receives an instruction from the command analysis unit 63 and inputs the character raster data 90 and the image raster data 95 stored by the generation device 30 from the shared buffer 40 (step S42). The decompression unit 70 decompresses the input character raster data 90 and image raster data 95 (step S45). The resolution conversion unit 73 unifies the resolutions of the character raster data 90 and the image raster data 95 to 720 dpi (step S47).
[0073]
The selection unit 75 checks whether the value of one pixel of the character raster data 90 is 1. If it is 1 (step S55), it means that a character is drawn on the pixel, and therefore a pixel of the character raster data 90 is selected (step S60). Then, the format converter 77 restores the color expression method converted by the converter 57 (step S62). If it is not 1 (step S55), it means that no character is drawn on the pixel, and therefore the pixel of the image raster data 95 is selected (step S65). By selecting in this way, raster data in a state where characters are superimposed on the image can be generated.
[0074]
The resolution conversion unit 73 doubles the resolution of the selected pixel (step S67). That is, the resolution of raster data obtained from the character raster data 90 and the image raster data 95 (hereinafter referred to as composite raster data 100) is 1440 dpi.
[0075]
The print data creation unit 80 creates print data from the pixels after the resolution conversion unit 73 performs resolution conversion (step S70). Specifically, color conversion, that is, a color described in the RGB color system is converted into CMY color system data, H / T processing is performed, and interlace processing is performed. The print data output unit 85 outputs the print data created by the print data creation unit 80 to the print engine (step S75). The processing from steps S55 to S75 is performed for all the pixels of the raster data.
[0076]
FIG. 8 is an explanatory diagram showing the state of processing performed by the print engine 35. The character raster data 90 is created at 720 dpi, and the image raster data 95 is created at 360 dpi. The resolution of the image raster data 95 is changed to 720 dpi, and the image raster data 95 or the character raster data 90 is selected for each pixel. The resolution is doubled for the selected pixel, and 1440 dpi composite raster data 100 is obtained. In this processing, as shown in FIG. 8, the pixel having the value “1” in the character raster data 90 is black, and the pixel having the value “0” in the character raster data 90 is RGB 24-bit gradation of the image raster data 95. Takes a value.
[0077]
In the present embodiment, an alpha channel in which a transmission coefficient or opacity is set for each dot is not provided, and the composite raster data 100 is determined depending on whether the value of the character raster data 90 is “0” or “1”. The gradation value and color are determined. The character raster data 90 is prioritized and the image raster data 95 does not have a transmission coefficient, instead of determining the gradation value and color of the combined raster data 100 in consideration of the transmission coefficient of each raster data. However, it may be configured to include an alpha channel, or the combined raster data 100 may be generated using the values of both the character raster data 90 and the image raster data 95.
[0078]
Next, exchange of print commands and raster data (hereinafter referred to as delivery processing) among the generation apparatus 30, the shared buffer 40, and the print engine 35 will be described. 9 and 10 are flowcharts showing the delivery process.
[0079]
First, the generation device 30 writes print task information including print settings such as print size and print resolution in a predetermined area of the shared buffer 40 (step S1), and a command for requesting execution of the print task is stored in the register of the print engine 35. Write (step S2).
[0080]
Upon receiving the print task execution command, the print engine 35 accesses a predetermined area of the shared buffer 40 to read the print task information (step S3), and based on the information such as the print size, the size of each of the input buffers B0 and B1 To decide. Then, the input buffers B0 and B1 are secured in the shared buffer 40, and information of the secured input buffers B0 and B1 (for example, the start address and data size of each buffer) is written in a predetermined area of the shared buffer 40 (step S4). .
[0081]
After securing the input buffers B0 and B1, the print engine 35 writes a print task response command in the register of the generation device 30 (step S5). The generation apparatus 30 may secure the input buffers B0 and B1.
[0082]
Next, the generation device 30 reads the input buffer information from the shared buffer 40 and grasps the position of the input buffer that stores the character raster data 90 and the image raster data 95 (step S6). Then, the character raster data 90 and the image raster data 95 are separately formed from the first band of the page, and stored in the character plane CP0 and the image plane PP0 of the first input buffer B0 (step S7).
[0083]
After storing the character of the first band and the raster data of the image, the generating device 30 writes the print request command for the raster data stored in the first input buffer B0 into the register of the print engine 35 (step S8). As a result, the print engine 35 accesses the first input buffer B0, reads the character raster data 90 and the image raster data 95 of the first band (step S9), performs color conversion processing, halftone processing, etc., and prints. To do.
[0084]
In the figure, “raster data formation 0” means that character and image raster data to be written to the first input buffer B0 is formed, and “raster data formation 1” means that the second The character and image raster data to be written to the input buffer B1 are formed. Similarly, “print 0” means that the raster data stored in the first input buffer B0 is read and printing processing is performed, and “print 1” means that raster data is received from the second input buffer B1. It means reading and printing.
[0085]
While the print engine 35 is printing the raster data read from the first input buffer B0, the generation device 30 generates raster data of the next band in parallel with this. The raster data of the next band is stored in the second input buffer B1 (step S10). After storing the raster data in each of the character plane CP1 and the image plane PP1 of the second input buffer B1, the generation device 30 prints the raster data of the second input buffer B1 to the print engine 35. A request is made (step S11).
[0086]
When the print engine 35 finishes printing the first band, the print engine 35 notifies the generating device 30 that the printing of the raster data in the first input buffer B0 has been completed (step S12). Thereby, the generation device 30 generates raster data of the third band and stores it in the first input buffer B0 (step S13).
[0087]
Similarly, the generation device 30 passes raster data to the print engine 35 while switching the input buffer to be used, and the print engine 35 reports the completion of printing each time printing of each band is completed (steps S14 to S24 (FIG. 9, see FIG. 10)).
[0088]
Then, after generating the raster data of the last band of the page to the print engine 35, the generation apparatus 30 requests the print engine 35 to respond to the end of the print task (step S25). When the print engine 35 finishes printing the last band, the print engine 35 notifies the generation device 30 that page printing is complete (step S26).
[0089]
A5. effect:
According to this embodiment configured as described above, a data processing function (character raster data 90 generation, image raster data 95 generation and band control) for interpreting print data and generating raster data for each band is provided. In addition to being executed by the generation device 30, other processing (resolution conversion, color conversion, H / T processing, etc.) performed after generation of raster data in band units is executed by the print engine 35. It is possible to prevent an excessive load from being applied to either one.
[0090]
In addition, since the raster data is transferred via the plurality of input buffers B0 and B1 secured in the shared buffer 40, the generation device 30 is in a state where the raster data in one input buffer is being printed by the print engine 35. Raster data of a new band can be written in the other input buffer, and the generation apparatus 30 and the print engine 35 can be operated in parallel to perform high-speed printing.
[0091]
Further, in each of the input buffers B0 and B1, a character plane CP for storing the character raster data 90 and an image plane PP for storing the image raster data 95 are formed. 90 and the image raster data 95 can be generated separately, and the print engine 35 can perform processing for obtaining the combined raster data 100 from both raster data.
[0092]
Further, priorities between raster data are set in advance so that the character raster data 90 has priority over the image raster data 95, and only pixels for which the transparent color is set on the character raster data 90 are selected. Therefore, the synthesized raster data 100 can be easily obtained from the character raster data 90 and the image raster data 95.
[0093]
In addition, when the character raster data 90 is given priority and the image raster data 95 is not provided with transparency information such as an alpha channel, the data size of the image raster data 95 can be reduced.
[0094]
Furthermore, the data size can be further reduced by providing the conversion unit 57 and the compression unit 59 that reduce the data size of the raster data.
[0095]
B. Second embodiment:
B1. processing:
In the second embodiment, print data is created from character raster data 90 and image raster data 95, respectively, and then a pixel is selected. FIG. 11 is a flowchart showing the processing until print data is generated from document data and output in the second embodiment. The flowchart on the left side is a flowchart of the generation apparatus 30, and the flowchart on the right side is a flowchart of the print engine 35. The generating apparatus 30 creates the character raster data 90 with a resolution of 720 dpi and the image raster data 95 with a resolution of 360 dpi. The compression release unit 70 of the print engine 35 releases the compression of the input character raster data 90 and the image raster data 95 (step S108), and the format conversion unit 77 restores the color expression method of the character raster data 90. (Step S110). Further, the resolution conversion unit 73 unifies the resolutions of the character raster data 90 and the image raster data 95 to 720 dpi (step S112).
[0096]
The print data creation unit 80 creates print data once individually from each pixel of the character raster data 90 and the image raster data 95 (step S120). The created print data is called character print data 105 and image print data 110, respectively. Next, the selection unit 75 checks whether the value of one pixel of the character print data 105 indicates that a dot is to be formed. When forming a dot (step S125), the pixel of the character print data 105 is selected (step S130). If no dot is formed (step S125), the pixel of the image print data 110 is selected (step S135). Further, the resolution conversion unit 73 doubles the resolution of the selected pixel (step S137). That is, the resolution of the composite print data (hereinafter referred to as composite print data 115) is 1440 dpi.
[0097]
FIG. 12 is an explanatory diagram showing the state of processing performed by the print engine 35 in the second embodiment. The character raster data 90 is created at 720 dpi, and the image raster data 95 is created at 360 dpi. The resolution of the image raster data 95 is changed to 720 dpi, and print data is created for each raster data. Next, the character print data 105 or the image print data 110 is selected for each pixel. The resolution is doubled for the selected pixel, and 1440 dpi composite print data 115 is obtained.
[0098]
B2. effect:
According to the present embodiment configured as described above, since the pixels are selected after the print data is created, clearer print data can be obtained.
[0099]
C. Variation:
Each embodiment of the present invention mentioned above is an illustration for explaining the present invention, and does not mean that the scope of the present invention is limited only to the embodiment. Those skilled in the art can implement the present invention in various other modes without departing from the gist of the present invention.
[0100]
For example, the case where the character raster data 90 is configured as binary data that takes either “1” or “0” has been described. However, the present invention is not limited to this, and the character raster data 90 may be formed with 3 bits or more. Good. When expressing the pixel of the character raster data 90 in 3 bits, for example, “000” is a transparent color, “001” is black, “010” is red, “011” is blue, “110” is green, and “111” is Characters can be printed with multiple character colors, such as white.
[0101]
The printer 25 is exemplified as the image processing apparatus. However, the present invention is not limited to this, and other image processing apparatuses such as a copying machine, a facsimile machine, and a multifunction machine (having a copying function and a printing function) may be used. Applicable. Further, the present invention is not limited to a serial printer such as an ink jet printer, and can also be applied to a page printer such as a laser printer.
[0102]
Further, the case where the character raster data 90 is prioritized over the image raster data 95 and the pixel value of the image is replaced with the value of the pixel of the character is exemplified. However, the present invention is not limited to this. The value of the image raster data 95 having a high gradation number is given priority by giving priority to the image raster data 95 having a low gradation number, such as obtaining the composite raster data 100 from the image raster data 95 capable of expressing more colors. Is also applicable to the case where the value is replaced with the value of the image raster data 95 having a low gradation number.
[0103]
Each process in the print engine 35 may be configured as an ASIC. Each process after the raster data generation does not require high-level command interpretation or the like, and merely performs standard processing mechanically. Therefore, the function of each unit can be easily implemented as hardware.
[0104]
The compression process and the process of changing the color expression method are not necessarily required, and may be performed only when it is desired to reduce the data size. Resolution conversion after pixel selection is not always necessary. Furthermore, if the generating device 30 creates raster data so that the resolutions of the character raster data 90 and the image raster data 95 match, it is not necessary to perform a process for matching the resolutions of the character raster data 90 and the image raster data 95.
[0105]
Moreover, the order of each process can be changed suitably. In other words, the processing for matching the resolutions of the character raster data 90 and the image raster data 95 may be performed before selecting the pixels, and the processing for restoring the color expression method of the character raster data 90 is performed before the print data is created. Just do it.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram of an embodiment of the present invention.
FIG. 2 is a functional block diagram of a printer 25. FIG.
FIG. 3 is an explanatory diagram showing a document 87 to be processed.
FIG. 4 is an explanatory diagram showing character raster data 90;
FIG. 5 is an explanatory diagram showing image raster data 95;
6 is a schematic diagram showing a configuration of a shared buffer 40. FIG.
FIG. 7 is a flowchart showing processing until print data is generated from document data and output in the first embodiment.
FIG. 8 is an explanatory diagram showing a state of processing performed by the print engine in the first embodiment.
FIG. 9 is a flowchart illustrating a transfer process among the generation apparatus 30, the shared buffer 40, and the print engine 35.
FIG. 10 is a flowchart illustrating a transfer process among the generation apparatus 30, the shared buffer 40, and the print engine 35.
FIG. 11 is a flowchart showing processing until print data is generated from document data and output in the second embodiment.
FIG. 12 is an explanatory diagram showing a state of processing performed by the print engine in the second embodiment.
[Explanation of symbols]
20 ... Computer
25 ... Printer
30 ... Generator
35 ... Print engine
40 ... Shared buffer
45 ... Input section
50: Dividing part
55 ... Raster data creation section
57: Conversion unit
59 ... Compression section
60 ... Communication Department
63: Command analysis unit
65: Raster data input section
70: Compression release unit
73 ... Resolution converter
75 ... Selection part
77 ... Format converter
80: Print data creation section
81 ... color conversion unit
82 ... H / T processing section
83. Interlace processing section
85: Print data output section
87 ... Document
90 ... character raster data
95: Image raster data
100: Composite raster data
105: Character print data
110: Image print data
115 ... Composite print data
B0: First input buffer
B1 ... second input buffer
CP: Character plane
CP0 ... character plane
CP1 ... Character plane
PP: Image plane
PP0: Image plane
PP1 ... Image plane
T1 ... Character color control table

Claims (7)

In an image processing apparatus that generates and synthesizes character raster data and image raster data separately,
A character generator for generating character raster data;
A character plane for storing the generated character raster data;
An image generator for generating image raster data;
An image plane for storing the generated image raster data ;
And images synthesizing unit for synthesizing said image raster data and the character raster data,
Bei to give a,
The character generator is
Assigning to each pixel included in the character raster data one of a plurality of values represented by n bits,
A specific value of the plurality of values indicates transparency, and a value other than the specific value of the plurality of values indicates a character color,
The image composition unit
When the pixel of the character raster data is assigned a value other than the specific value, the pixel of the character raster data is selected, and when the specific value is assigned to the pixel of the character raster data , by selecting a pixel of the image raster data, the image processing apparatus characterized that you synthesized with the character raster data and the image raster data. Each pixel included in the prior Kiga image raster data indicate any of a plurality of colors represented by m bits, have a have information for setting the transmission coefficient, according to 請 Motomeko 1 Image processing apparatus. The particular value other than the further to include the character color control table and character color is kicked pair応付image processing apparatus according to billed to claim 1 or 2. And a first data processing device and a second data processing device,
The first data processing device includes the character generation unit and the image generation unit,
The second data processing device includes the image composition unit,
The character plane and the image plane are stored in a buffer memory shared by the first data processing device and the second data processing device,
4. The image processing apparatus according to claim 1, wherein raster data is transferred via the buffer memory.   The image processing apparatus according to claim 4, wherein the buffer memory includes a plurality of shared buffer areas, and the shared buffer areas are switched and used. In an image processing method for generating and combining character raster data and image raster data separately,
Generating character raster data; and
Storing the generated character raster data in a character plane;
Generating image raster data;
Storing the generated image raster data in an image plane ;
Comprising the steps of synthesis and the image raster data and the character raster data,
Including
The character raster data generation step includes:
Assigning to each pixel included in the character raster data one of a plurality of values represented by n bits, wherein the specific value of the plurality of values is transparent; A value other than the specific value of the plurality of values includes an assigning step indicating a character color;
The synthesis step includes
If it assigned a value other than the character raster data pixel to the specific value, the character and select the pixel of the raster data, when said value of said on character raster data pixel particular is assigned to, by selecting a pixel of the image raster data, images processing method characterized by comprising the step of combining the said character raster data and the image raster data. In a program for controlling an image processing apparatus that generates and synthesizes character raster data and image raster data separately,
A function to generate character raster data;
A function of storing the generated character raster data in a character plane;
A function to generate image raster data;
A function of storing the generated image raster data in an image plane ;
A function of synthesis and the image raster data and the character raster data,
Was revealed real to the image processing apparatus,
The character raster data generation function is
A function of allocating any one of a plurality of values represented by n bits to each pixel included in the character raster data, wherein the specific value of the plurality of values is transparent. A value other than the specific value of the plurality of values includes an assignment function indicating a character color;
The synthesis function is
When a pixel other than the specific value is assigned to the pixel of the character raster data, the pixel of the character raster data is selected, and when the specific value is assigned to the pixel of the character raster data, by selecting the pixels of the image raster data, programs, characterized in that it comprises a function of combining the said character raster data and the image raster data.

Images