JP4136894B2 - Printing apparatus, printing method, and storage medium storing computer-readable program - Google Patents

Description

  The present invention relates to a printing apparatus and a printing method for receiving and processing print information from a plurality of computers on a network via a predetermined interface, and a storage medium storing a computer-readable program.

  In recent years, information processing systems have been generalized and widely used. Under such circumstances, many electronic documents created on the information processing system are created, and output demand to the color printing apparatus tends to increase, and a high-speed and inexpensive color printing apparatus is desired. .

  Conventionally, a printing system that interprets a page description language (PDL) transmitted from a host computer or a print server and creates a raster image creates a display list (DL) that is an intermediate language after interpreting the PDL. It is common to perform raster image conversion (rendering) from DL.

  At this time, since the size of the PDL data is not limited, the size of the DL created from the PDL data may be very large. In addition, when the DL becomes complicated and its size increases, the work area used by the renderer that renders the DL also increases.

  However, the amount of memory installed in the printing apparatus is finite, and due to cost restrictions, there is often no sufficient amount to store the DL.

Therefore, the size of the area for storing the DL and the work area that can be used by the renderer are limited, and there is a restriction that a DL larger than a predetermined size cannot be processed.

  In order to avoid this restriction, a process called fallback is performed. Fallback renders the DL generated once when the DL size exceeds a certain size, or when the work area for processing the DL exceeds a certain size. The raster image is created and the DL created up to that point is cleared once.

  This raster image is added again to a part of DL as a background image of the drawing area.

Since this background image is usually compressed, the size of the added DL is smaller than the original DL size. Therefore, a large DL can be processed in a limited memory space by creating the remaining DL in this vacant area. In addition, since the renderer work area is cleared at the end of rendering during fallback, the size restriction of the work area can be avoided, and a low-cost printing apparatus can be provided. For example, the following Patent Document 1 has already been published.
JP 7-137355 A

  On the other hand, the raster image created in the process of performing the fallback processing as described above is compressed and added to the DL list, and the compressed image created at this time must also be within a predetermined size.

  In particular, in a color image, the size of a raster image created at the time of rendering is very large. In lossless compression, the compressed image cannot often be stored within a predetermined size, and lossy compression is usually used.

  However, using lossy compression degrades the compressed image. Therefore, when the remaining front image is drawn on the compressed image having deteriorated image as a background, there is a problem that the boundary line becomes conspicuous because there is a difference in image quality between the front surface and the background.

  FIG. 9 is a diagram for explaining an example of a printing result subjected to irreversible compression processing in a conventional printing apparatus.

  In FIG. 9, reference numeral 301 denotes a printing result. For example, a background image is located above the position 310 and a front image is located below the position 310 due to a difference in image quality between the front surface and the background. There was a problem that only conspicuous low-quality printing results could be obtained.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to reduce a difference in image quality between a deteriorated image and an undegraded image, thereby demarcating the boundary between the deteriorated image and the undegraded image. It is an object to provide a printing apparatus and printing method capable of obtaining an inconspicuous good printing result, and a storage medium and program storing a computer-readable program.

  The printing apparatus of the present invention that achieves the above object has the following configuration.

A creation means for creating a display list, a fallback means for rendering and compressing the display list to generate a background image, and registering the generated background image in the display list, and a display list for one page being generated Determining means for determining whether or not the degree of deterioration of the background image generated by the fallback means is greater than or equal to a threshold; and if the degree of deterioration of the background image generated by the fallback means by the determining means is not greater than or equal to the threshold If determined, the background image is generated by compressing the degraded image generated by rendering the background image registered by the fallback means of the display list and the non-degraded image generated by rendering the display list. And add the generated background image to the display list. Without performing the processing of the case where the degree of deterioration of the fallback means the background image generated by is determined to be equal to or larger than the threshold, to render the background image registered by the fallback means of the display list by the discriminating means image and display list that has deteriorated, which is generated by compressing an image that is not degraded are generated by rendering to generate a background image Te, again fall back to the generated background image carries out a process to be registered in the display list And a rendering means for rendering a display list to generate a raster image, and a printing means for executing printing based on the raster image generated by the rendering means.

  According to the present invention, it is possible to reduce the difference in image quality between a deteriorated image and an undegraded image, and to obtain an excellent print result in which the boundary between the deteriorated image and the undegraded image is not noticeable.

  Next, the best mode for carrying out the present invention will be described with reference to the drawings.

  Before describing the configuration of the present embodiment, the configuration of a laser beam printer suitable for applying the present embodiment will be described with reference to FIG. Needless to say, the printer to which the present embodiment is applied is not limited to a laser beam printer, but may be a printer of another printing method (such as an ink jet printer).

  FIG. 1 is a cross-sectional view showing the configuration of an output device to which the present invention can be applied.

  In FIG. 1, reference numeral 1000 denotes an LBP main body (LBP), which is print information (character code, etc.), form information, macro instructions, etc. supplied from an external information source such as a host computer connected to the outside via a network or a direct interface. Are input and stored, and a corresponding character pattern, form pattern, or the like is created according to the information, and an image is formed on a recording sheet or the like as a recording medium.

  Reference numeral 1012 denotes an operation panel on which switches for operation, an LED display, and the like are arranged. Reference numeral 1001 denotes a printer control unit that controls the entire LBP 1000 and analyzes character information supplied from an external network or the like.

  The printer control unit 1001 mainly converts character information into a video signal having a corresponding character pattern and outputs the video signal to the laser driver 1002. The laser driver 1002 is a circuit for driving the semiconductor laser 1003, and switches on / off the laser light 1004 emitted from the semiconductor laser 1003 in accordance with the input video signal. The laser beam 1004 is shaken in the left-right direction by the rotary polygon mirror 1005 to scan and expose the electrostatic drum 1006.

  As a result, an electrostatic latent image of a character pattern is formed on the electrostatic drum 1006. This latent image is developed by a developing unit 1007 disposed around the electrostatic drum 1006 and then transferred to a recording sheet.

A cut sheet is used as the recording paper, and the cut sheet recording paper is stored in a paper cassette 1008 mounted on the LBP 1000 and is taken into the apparatus by a paper feed roller 1009, a transport roller 1010, and a transport roller 1011. The drum 1006 is supplied.

[First Embodiment]
FIG. 2 is a block diagram illustrating the configuration of the printer control system in the printing apparatus according to the first embodiment of the present invention. The same components as those in FIG. 1 are denoted by the same reference numerals.

  In the printer control unit 1001 shown in FIG. 2, a MAIN-CPU (CPU) 1 is a printer CPU, and is connected to the system bus 5 based on a control program stored in the ROM 4 or a control program stored in the external memory 7. Access to various devices is comprehensively controlled, and an image signal is output as output information to a printing unit (printer engine) 9 connected via the printing unit interface 8.

  The ROM 4 stores a control program for the MAIN-CPU 1 as shown in flowcharts of FIGS. 3, 4, and 5, which will be described later, and data necessary for control of the LBP 1000. The MAIN-CPU 1 is configured to be able to communicate with an external device such as a host computer connected to the external network 3000 via the I / O 11.

  Although it is assumed that communication is performed with the host computer via an external network, it goes without saying that communication may be performed by directly connecting to the host computer via an interface (not shown).

  A RAM 2 functions as a main memory / work area of the MAIN-CPU 1. The RAM 2 is configured so that the memory capacity can be expanded by an optional RAM connected to an expansion port (not shown). Also, the PDL transmitted from the host computer is stored, and the DL generated based on the PDL is stored.

  Reference numeral 3 denotes an image output buffer prepared on the RAM 2, in which a raster image and attribute bits created by a hard renderer 20 described later are recorded as a fallback buffer and an output buffer. The compressed image stored in the image output buffer is decompressed by the CPU or decompression unit and transferred to the printing unit.

  A memory controller (MC) 6 controls access to the external memory 7 such as a hard disk. A hard renderer 20 has a local memory 21 therein. The hard renderer 20 interprets the display list (DL) transferred to the local memory 21 or the DL on the RAM 2 as it is, and creates an attribute bit corresponding to each pixel of the raster image and the raster image.

  Each attribute bit generated here is composed of three bit fields, 4 bits in total: 1 bit color bit, 1 bit thin line bit, and 2 bit object type bit.

  The color bit indicates whether the corresponding pixel is a pixel constituting a color object or a pixel constituting a monochrome object. When this bit is “0”, the color bit is a pixel constituting the color object. When it is “1”, it indicates a pixel constituting a monochrome object.

  The thin line bit indicates whether or not the corresponding pixel is a pixel constituting a thin line. When this bit is “1”, it indicates that the pixel constitutes a thin line.

  The object type bit indicates what kind of drawing object the corresponding pixel constitutes. When it is “01”, it is a pixel that constitutes a character object, and when it is “10”, it is a pixel that constitutes a graphics object. Yes, when it is “11”, it is a pixel constituting an image object, and when it is “00”, this pixel indicates that no object is constructed.

  The irreversible compression unit 22 performs irreversible compression on the raster image and stores it in the image output buffer 3 on the RAM 2. The lossy compression unit according to the present embodiment employs JPEG. JPEG can change the compression rate of an image to be compressed by changing the Q table used at the time of compression. The higher the compression rate, the greater the image degradation.

  Here, JPEG is used as the irreversible compression, but the present invention is not applicable to any irreversible compression method that can change the compression rate.

  The lossless compression unit 23 performs lossless compression on the attribute bits and stores them in the image output buffer 3. Based on the attribute bits generated by the hard renderer 20, the image processing unit 24 processes character image processing, image image processing, graphic image processing, color image processing, and monochrome image processing on raster data. Processing or image processing for fine lines or a combination thereof is performed.

  In the printer control system configured as described above, an embodiment of the present invention will be described according to the flowcharts of FIGS. 3, 4, and 5.

  The LBP 1000 has, for example, six types of Q tables to be set in JPEG of the lossy compression unit 22 when compressing a raster image generated at the time of rendering described later. Each Q table has identifiers 1 to 6, and these identifiers are called Q table IDs for convenience. Each Q table is set so as to have a higher compression ratio as it has a larger Q table ID. Therefore, as a Q table having a larger Q table ID is used, image degradation increases.

  Here, the number of Q table types is six, but it goes without saying that this number is not limited.

  In this embodiment, the compression results using the Q tables from the Q table ID 1 to the Q table ID 5 are at a glance that image degradation is not noticeable, but the Q table of the Q table ID 6 is the compression result of most images. Is designed to be stored in a fallback buffer and an image spool area, which will be described later, and image degradation using this Q table is very large.

  For this reason, when a foreground image is drawn on a compressed image compressed using the Q table of Q table ID 6 at the time of fallback as a background image, the difference in image quality becomes very large, as shown in FIG. The boundary part will be very conspicuous.

  Therefore, in this embodiment, the variable QTH is set to “6”, and only when the Q table of the Q table ID 6 is used in the compression during fallback of the PDL job printing process described later, the fall back is generated again. I have to.

  FIG. 3 is a flowchart showing an example of the first data processing procedure in the printing apparatus according to the present invention. Based on the print control program stored in the ROM 4, the PDL job printing processed by the MAIN-CPU 1 when receiving a PDL job. Corresponds to the processing procedure. In addition, S400-S414 shows each step.

  When the LBP 1000 receives a PDL job from the external network 3000 (S401), the process proceeds to step S402, the variable current QID indicating the currently set Q table ID is set to “1”, and the process proceeds to step S403.

  In step S403, the MAIN-CPU 1 generates a display list (DL) on the RAM 2 while performing PDL data analysis processing, and issues a print or fallback DL.

  When the DL is generated in step S403, the printing DL is normally issued at the timing when the DL for one page is created. However, the size of the local memory of the hard renderer 20 and the size of the work table are always inspected. If the DL being generated exceeds the size of the local memory, the work table used when rendering the DL being generated is rendered. If the size exceeds the table size mounted on the hard renderer 20, a fallback DL is issued, and the process proceeds to step S404.

  In step S404, it is determined from the inspection flag whether the DL issued in step S403 is a print DL or a fallback DL. If it is determined that the DL is a fallback DL, the process proceeds to step S405. The fallback process will be described later in detail, and the process returns to step S403 to continue the analysis of PDL data and the generation of DL.

  Thereafter, when a DL for one page is created without any fallback, a printing DL is issued, and the process proceeds to S403. For example, in the example illustrated in FIG. 9, a DL of an image that is deteriorated due to compression is generated in a portion above the position 310 and an image that is not deteriorated in a portion below 310 is generated, and a print DL is issued.

  On the other hand, if it is determined in step S404 that the DL issued in step S403 is a printing DL, the process proceeds to step S406.

  In step S406, it is determined whether or not the variable current QID is equal to or greater than the variable QTH. If the variable current QID is equal to or greater than QTH, the process proceeds to step S407 to execute the recompression process due to the fallback again. Process.

  In step S408, the DL of the background image created and registered during the fallback in step S407 is issued as a printing DL. Note that only the background image is included in the print DL as a drawing object.

  In steps S407 and S408, in the example shown in FIG. 9, an image deteriorated by compression is rendered in the portion above the position 310, and an image not deteriorated is rendered in the portion below the position 310, from the rendered position 310. The upper part applies compression that deteriorates again to the image deteriorated due to compression and the part below the position 310 does not deteriorate, and creates and issues a DL that has been subjected to compression that deteriorates the entire image.

  The portion above the position 310 is subjected to compression that deteriorates twice, and the portion below the position 310 is subjected to compression that deteriorates once, but the difference between the deteriorated image and the image that does not deteriorate In contrast, since there is not much difference between an image degraded twice and an image degraded once, the boundary of the position 310 becomes inconspicuous.

  In step S409, the image output buffer for storing the compressed image after rendering is set to the image spool for storing the image for printing, and a mode for compressing the raster image generated by rendering is suitable for printing. The mode is set to packet JPEG which is compressed on a packet basis.

  Next, in step S410, the print DL issued in step S403 or step S408 is rendered using the hard renderer 20 to generate a raster image, and then a compressed image is created. Details of this processing will be described later.

  Next, in step S411, the compressed image stored in the image spool in the rendering process in step S410 and the compressed attribute bit are transferred to the image processing unit 24, and the compressed image is decompressed into a raster image, and an appropriate image according to the attribute bit. Apply processing.

  In step S412, the raster image subjected to the image processing is transferred to the printing unit 9 and printed on paper.

  Next, in step S413, it is determined whether or not the processing of all pages of the PDL job received in step S402 has been completed. If the processing of all pages has been completed, the printing processing of the PDL job is terminated (S414). If PDL data to be processed still remains, the process returns to step S402, the current QID is initialized to 1, and then the PDL data analysis / DL generation process is continued.

  Hereinafter, the fallback processing executed in steps S405 and S407 will be described with reference to the flowchart shown in FIG.

  FIG. 4 is a flowchart showing an example of a second data processing procedure in the printing apparatus according to the present invention, and corresponds to the detailed procedure of the fallback processing executed in steps S405 and S407 shown in FIG. In addition, S500-S504 shows each step.

  When the fallback process is started (S500), in step S501, the image output buffer in which the compressed image after rendering is stored is set in the fallback buffer, and the mode for compressing the raster image generated by rendering is set to fall. A mode suitable for back-up, specifically, JPEG is set for each scan line.

  In step S502, the same processing as step S410 shown in FIG. 3 is executed except for rendering processing, for example, the image output buffer and the compression mode at the time of compression.

  When the rendering process ends, in step S503, the compressed image stored in the image spool in step S502 and the compressed attribute bits are registered again in the DL as a background image, and the fallback process ends (step S503). S504).

  Hereinafter, the rendering process executed in steps S410 and S502 will be described with reference to the flowchart shown in FIG.

  FIG. 5 is a flowchart showing an example of a third data processing procedure in the printing apparatus according to the present invention. The raster image generated by rendering the DLs in steps S410 and S502 in FIGS. 3 and 4 is compressed. This corresponds to the detailed procedure of the rendering process until it is stored in the output buffer set in the immediately preceding step. S600 to S609 indicate each step.

  First, when the rendering process is started (S600), the DL issued in step S403 or step S408 shown in FIG. 3 is transferred to the local memory 21 on the hard renderer 20 (S601).

  In step S602, the Q table of the Q table ID set in the variable current QID is set in the lossy compression unit 22.

  In step S603, after performing various initialization processes such as register setting of the hard renderer 20, a rendering start signal is sent to start rendering of the DL on the local memory 21.

  In step S604, the hard renderer 20 generates a raster image for 64 scan lines and attribute bits corresponding to the raster image in a buffer on the local memory while analyzing the DL on the local memory 21. Although the raster image for 64 scan lines is generated here, it goes without saying that the number of scan lines is an example, and other scan lines may be used.

  Next, in step S605, the raster image generated in step S604 is transferred to the irreversible compression unit 22, and compression is performed using the Q table set in step S602 and the compression mode set in advance. The compressed image is stored in a preset image output buffer, and the attribute bits generated in step S604 are transferred to the lossless compression unit 23 and subjected to lossless compression. Store in image output buffer.

  In step S606, when the compressed image and the compressed attribute bits in step S605 are stored in the image output buffer, it is determined whether or not the compressed image and the compressed attribute bits can always be stored in the image output buffer. If YES in step S607, the flow advances to step S607 to check whether or not the rendering of one page has been completed by checking the number of rendered scan lines and determine that the rendering of one page has been completed. If so, the rendering process is terminated (S608).

  On the other hand, if it is determined in step S607 that rendering for one page has not been completed, the process returns to step S604 and the remaining rendering is continued.

  If it is determined in step S606 that the compressed image or the compressed attribute bit does not fit in the image output buffer, the process proceeds to step S609, the value of the variable current QID is incremented, the process returns to step S602, and the variable current QID is set. The Q table with the set Q table ID is reset in the lossy compression unit 22 and rendering is restarted.

  As described above, according to the first embodiment, when a raster image compressed using the Q table of the Q table ID 6 having a large image degradation at the time of fallback is used as the background, the fallback is generated again in the front image drawing, Since the image is also compressed in the same manner as the background image, the boundary between the background image and the front image becomes inconspicuous as shown in the print result example shown in FIG.

  FIG. 6 is a diagram illustrating a print output example for a compressed image in the printing apparatus according to the present invention.

  In FIG. 6, reference numeral 302 denotes a print output obtained by applying the present embodiment. Compared with the print output 301 before application of the present embodiment shown in FIG. It can be confirmed that the border with the image has disappeared.

[Second Embodiment]
You may comprise so that the value of the variable QTH which was fixed in 1st Embodiment may be provided with the user interface which a user can set from the operation panel 1012. FIG. The embodiment will be described below.

  FIG. 7 is a view showing an example of a compressed image output selection screen in the printer use setting in the printing apparatus showing the second embodiment of the present invention, and is displayed on the LCD provided in the operation panel 1012 shown in FIG. This is an example screen.

  In FIG. 7, reference numeral 703 denotes a slider, and the user can freely move the slider 703 within the slider movable range 702 by operating the operation panel 1012, and the position of the slider 703 within the slider movable range 702 A value registered in the variable QTH is selected.

  When the OK button 711 is selected when the center position of the slider 703 is in the range 704, “1” is registered in the variable QTH, and when the OK button 711 is selected when the center position of the slider 703 is in the range 705, When “2” is registered in the variable QTH and the center position of the slider 703 is in the range of 706, when the OK button 711 is selected, “3” is registered in the variable QTH and the center position of the slider 703 is 707. When the OK button 711 is selected when the range is within the range, “4” is registered in the variable QTH. When the center position of the slider 703 is within the range 708, when the OK button 711 is selected, the variable QTH is set to “5”. Is registered and the center position of the slider 703 is in the range of 709, and when the OK button 711 is selected, the variable QTH is changed to “ "It is registered. Reference numeral 710 denotes a cancel button.

  From the viewpoint of the user, the QTH value is small, and a smoother image appears when recompression by fallback is performed from the stage of low image degradation.

  As described above, according to the second embodiment, the user can select the degree of image deterioration at which compression of the front image is started, and the user can adjust the image quality more finely.

[Third Embodiment]
In the first embodiment, during DL creation, fallback processing is performed in step S405, and if it is determined in step S406 that a part of the image generated by the fallback has exceeded a specific degree of degradation, the fallback processing in step S407 is performed. In particular, after rendering for one page, the entire image is compressed to cause the same degree of degradation, and a DL including only the compressed image is created.

  In the present embodiment, when the processing from step S406 to step S408 is omitted, and during the rendering processing of step S410, the DL is examined to determine whether a part of the image exceeds a specific degree of degradation, and when it is determined that it has exceeded In step S604, which shows details of step S410, the DL including the image generated by the fallback is rendered. In step S605, which shows details of step S410, the image rendered in step S604 is compressed with a specific degree of degradation. This can be realized by outputting to the output buffer, reading the compressed image in the image output buffer in step S411, performing decompression and image processing in the image processing unit, transferring to the engine in step S412, and printing.

  The configuration of a data processing program that can be read by the printing apparatus according to the present invention will be described below with reference to the memory map shown in FIG.

  FIG. 8 is a diagram illustrating a memory map of a storage medium that stores various data processing programs that can be read by the printing apparatus according to the present invention.

  Although not particularly illustrated, information for managing a program group stored in the storage medium, for example, version information, creator, etc. is also stored, and information depending on the OS on the program reading side, for example, a program is identified and displayed. Icons may also be stored.

  Further, data depending on various programs is also managed in the directory. In addition, a program for installing various programs in the computer, and a program for decompressing when the program to be installed is compressed may be stored.

  The functions shown in FIGS. 3 to 5 in this embodiment may be performed by the host computer by a program installed from the outside. In this case, the present invention is applied even when an information group including a program is supplied to the output device from a storage medium such as a CD-ROM, a flash memory, or an FD, or from an external storage medium via a network. Is.

  As described above, a storage medium storing software program codes for realizing the functions of the above-described embodiments is supplied to the system or apparatus, and the computer (or CPU or MPU) of the system or apparatus stores the storage medium in the storage medium. It goes without saying that the object of the present invention can also be achieved by reading and executing the programmed program code.

  In this case, the program code itself read from the storage medium realizes the novel function of the present invention, and the storage medium storing the program code constitutes the present invention.

  As a storage medium for supplying the program code, for example, a flexible disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a CD-R, a magnetic tape, a nonvolatile memory card, a ROM, an EEPROM, or the like is used. it can.

  Further, by executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but also an OS (operating system) or the like running on the computer based on the instruction of the program code. It goes without saying that a case where the function of the above-described embodiment is realized by performing part or all of the actual processing and the processing is included.

  Further, after the program code read from the storage medium is written to a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, the function expansion is performed based on the instruction of the program code. It goes without saying that the case where the CPU or the like provided in the board or the function expansion unit performs part or all of the actual processing and the functions of the above-described embodiments are realized by the processing.

  The present invention is not limited to the above embodiments, and various modifications (including organic combinations of the embodiments) are possible based on the spirit of the present invention, and these are excluded from the scope of the present invention. is not.

  Although various examples and embodiments of the present invention have been shown and described, those skilled in the art will recognize that the spirit and scope of the present invention are not limited to the specific descriptions in the present specification, but the following embodiments. Needless to say, is also included. Hereinafter, Embodiments 1 to 10 will be described.

[Embodiment 1]
A printing apparatus that compresses raster image information generated in accordance with input print information and draws a front image on the compressed image as a background, and is an image obtained by compressing the compressed background image. Image degradation degree detection means for detecting the degree of degradation (for example, step S406 shown in FIG. 3), and after the front image is rendered, image degradation of the same degree as that detected by the image degradation degree detection means. A printing apparatus comprising: a recompression unit (for example, step S407 shown in FIG. 3) that performs a compression process to be performed on the entire image.

[Embodiment 2]
If the degree of image deterioration detected by the image deterioration degree detection means is equal to or greater than a certain value, after the front image is rendered, image deterioration equivalent to the degree of image deterioration detected by the image deterioration degree detection means is caused. The printing apparatus according to claim 1, further comprising re-compression means (for example, step S407 shown in FIG. 3) for compressing the entire image.

[Embodiment 3]
Rendering means (for example, step S410 shown in FIG. 3) that interprets the intermediate language to generate a raster image, and when the intermediate language cannot be rendered at once using the rendering means, the intermediate language is partially processed And a fallback unit that compresses a raster image generated by rendering by the rendering unit and adds the compressed image as a background to the intermediate language again, and the recompression unit includes the fallback unit. The printing apparatus according to Embodiment 1.

[Embodiment 4]
The printing apparatus according to claim 2, further comprising an image deterioration degree designation unit that allows a user to designate an image deterioration degree of a background image to be recompressed by the recompression unit.

[Embodiment 5]
A control method in a printing apparatus that compresses raster image information generated according to input print information and draws a front image on the compressed image as a background, the method comprising: An image deterioration degree detection step (for example, step S406 shown in FIG. 3) for detecting the degree of image deterioration due to compression, and the image deterioration degree detected by the image deterioration degree detection means after the front image is rendered. A control method in a printing apparatus, comprising: a recompression step (for example, step S407 shown in FIG. 3) for performing compression processing that causes image degradation on the entire image.

[Embodiment 6]
If the image degradation level detected by the image degradation level detection step is equal to or greater than a certain value, after the front image is rendered, image degradation similar to the level of image degradation detected by the image degradation level detection step occurs. 6. The control method according to embodiment 5, further comprising a recompression step (for example, step S407 shown in FIG. 3) for compressing the entire image.

[Embodiment 7]
A rendering step for interpreting the intermediate language to generate a raster image (for example, step S410 shown in FIG. 3), and if the intermediate language cannot be rendered at once using the rendering step, the intermediate language is partially processed. The raster image generated by the rendering step is compressed, and then a fallback step (for example, step S407 shown in FIG. 3) is added to the intermediate language again using the compressed image as a background. The recompression step includes the fallback. The control method according to Embodiment 5, wherein the control method comprises steps.

[Embodiment 8]
Embodiment 6 wherein the recompression step includes an image degradation degree designation step (for example, designation via a user interface shown in FIG. 7) in which a user designates an image degradation degree of a background image to be recompressed. Control method.

[Embodiment 9]
A computer-readable storage medium storing a program for realizing the control method according to claim 5.

[Embodiment 10]
The program which implement | achieves the control method in any one of Claims 5-8.

  According to each of the above embodiments, it is possible to obtain a good print result in which the boundary between the front image and the background image is not noticeable by reducing the difference in image quality between the front image and the background image.

  As described above, according to the embodiment of the present invention, the raster image information generated according to the input print information is compressed, and the front image is drawn on the compressed image as a background. In the apparatus, after the front image is rendered, the degree of image degradation due to compression of the compressed background image is detected, and a compression process that causes image degradation equivalent to the detected degree of image degradation is performed on the entire image. As a result, the difference in image quality between the front image and the background image can be reduced, and an excellent print result in which the boundary between the front image and the background image is not conspicuous can be obtained.

It is sectional drawing which shows the structure of the output device which can apply this invention. 1 is a block diagram illustrating a configuration of a printer control system in a printing apparatus according to a first embodiment of the present invention. 6 is a flowchart illustrating an example of a first data processing procedure in the printing apparatus according to the present invention. It is a flowchart which shows an example of the 2nd data processing procedure in the printing apparatus which concerns on this invention. 10 is a flowchart illustrating an example of a third data processing procedure in the printing apparatus according to the present invention. It is a figure which shows the example of a print output with respect to the compressed image in the printing apparatus which concerns on this invention. It is a figure which shows an example of the compression image output selection screen in the printer use setting in the printing apparatus which shows 2nd Embodiment of this invention. It is a figure explaining the memory map of the storage medium which stores the various data processing program which can be read with the printing apparatus which concerns on this invention. It is a figure explaining the example of the printing result by which the irreversible compression process in the conventional printing apparatus was carried out.

Explanation of symbols

1 CPU
2 RAM
3 Image output buffer 20 Hard renderer 22 Lossy compression unit
23 Lossless compression unit
24 Image processing unit 1000 LBP
1001 Printer control unit 3000 External network

Claims (12)

Creating means for creating a display list;
A fallback means for rendering and compressing the display list to generate a background image, and registering the generated background image in the display list;
A discriminating unit for discriminating whether or not the degree of deterioration of the background image generated by the fallback unit is greater than or equal to a threshold after the display list for one page is generated;
When the determination means determines that the degree of deterioration of the background image generated by the fallback means is not equal to or greater than a threshold value, the deteriorated image generated by rendering the background image registered by the fallback means of the display list And a non-degraded image generated by rendering the display list to generate a background image, and processing for registering the generated background image in the display list is not performed, and the fallback means by the determination means When it is determined that the degradation level of the background image generated by the above is greater than or equal to the threshold , the degraded image generated by rendering the background image registered by the fallback means of the display list and the display list are rendered. Compress the generated non-degraded image Generating an image, and re-fallback means the generated background image performs a process of registering the display list,
Rendering means for rendering a display list to generate a raster image;
And a printing unit that executes printing based on the raster image generated by the rendering unit.   The printing apparatus according to claim 1, wherein the determination unit determines that the background image generated by the fallback unit is degraded when the compression variable is equal to or greater than a predetermined value.   The fallback means, when the display list being generated exceeds the size of the memory, renders and compresses the display list to generate a background image, and registers the generated background image in the display list. Item 2. The printing apparatus according to Item 1.   If the size of the table used when rendering the display list being generated exceeds a predetermined size, the fallback means renders and compresses the display list to generate a background image, and the generated background image is displayed in the display list. The printing apparatus according to claim 1, wherein the printing apparatus is registered with the printing apparatus. A fallback step of rendering and compressing the display list to generate a background image and registering the generated background image in the display list;
A determination step of determining whether or not the degree of deterioration of the background image generated by the fallback step is equal to or greater than a threshold after the display list for one page is generated;
When the determination step determines that the degree of deterioration of the background image generated by the fallback step is not equal to or greater than a threshold, the deteriorated image generated by rendering the background image registered by the fallback step of the display list And a non-degraded image generated by rendering the display list to generate a background image, and a process of registering the generated background image in the display list is not performed, and the fallback step by the determination step When it is determined that the degradation level of the background image generated by the above is greater than or equal to the threshold , the degraded image generated by rendering the background image registered by the fallback step of the display list and the display list are rendered. Generated degradation Not to compress the image to generate a background image, and re-fallback step the generated background image performs a process of registering the display list,
A rendering step for rendering the display list to generate a raster image;
And a printing step for executing printing based on the raster image generated by the rendering step.   6. The printing method according to claim 5, wherein the determination step determines that the background image generated by the fallback step is deteriorated when the compression variable is equal to or greater than a predetermined value.   The fallback step, when the display list being generated exceeds the size of the memory, renders and compresses the display list to generate a background image, and registers the generated background image in the display list. Item 6. The printing method according to Item 5.   If the size of the table used when rendering the display list being generated exceeds a predetermined size, the fallback step renders and compresses the display list to generate a background image, and the generated background image is displayed in the display list. The printing method according to claim 5, wherein the printing method is registered. A fallback step of rendering and compressing the display list to generate a background image and registering the generated background image in the display list;
A determination step of determining whether or not the degree of deterioration of the background image generated by the fallback step is equal to or greater than a threshold after the display list for one page is generated;
When the determination step determines that the degree of deterioration of the background image generated by the fallback step is not equal to or greater than a threshold, the deteriorated image generated by rendering the background image registered by the fallback step of the display list And a non-degraded image generated by rendering the display list to generate a background image, and a process of registering the generated background image in the display list is not performed, and the fallback step by the determination step When it is determined that the degradation level of the background image generated by the above is greater than or equal to the threshold , the degraded image generated by rendering the background image registered by the fallback step of the display list and the display list are rendered. Generated degradation Not to compress the image to generate a background image, and re-fallback step the generated background image performs a process of registering the display list,
A rendering step for rendering the display list to generate a raster image;
A computer-readable storage medium storing a program that causes a computer to execute a printing step of executing printing based on a raster image generated by the rendering step.   The storage medium according to claim 9, wherein the determination step determines that the background image generated by the fallback step is deteriorated when the compression variable is equal to or greater than a predetermined value.   The fallback step, when the display list being generated exceeds the size of the memory, renders and compresses the display list to generate a background image, and registers the generated background image in the display list. Item 10. The storage medium according to Item 9.   If the size of the table used when rendering the display list being generated exceeds a predetermined size, the fallback step renders the display list and compresses it to generate a background image, and the generated background image is displayed in the display list. The storage medium according to claim 9, wherein the storage medium is registered.

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