JP5268813B2 - Computer program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To transfer image data generated by an application to an image forming apparatus without decreasing image quality excessively. <P>SOLUTION: A control unit 41 and a data compression process unit 42 are achieved by executing a driver program 21. If image data output from an application 32-i has a bitmap format, the control unit 41 causes the data compression process unit 42 to compress the image data by a compression method (reversible delta row compression or irreversible JPEG compression) corresponding to the set value of image compression setting, and transfers the compressed image data to the image forming apparatus 2. If the data is compressed by an irreversible compression method (e.g., JPEG compression), the image data output from the application 32-i is directly transferred to the image forming apparatus 2 regardless of the value set for the image compression. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a computer program.

  When image data is transferred from the host computer to the printer, the image data may be compressed before being transferred in order to reduce the amount of transfer data. In such a case, the host computer selects a compression method so that the total time of image data compression, transfer, and expansion is shortened (see, for example, Patent Document 1), or selects a compression method according to the content of the image data. (See, for example, Patent Document 2).

JP-A-9-146732 JP 2001-282482 A

  The driver performs the image data transfer process as described above. In the host computer, an application is operating in addition to the driver, and the application generates image data to be transferred to an image forming apparatus such as a printer.

  There are a plurality of image data formats generated by an application, and image data may be generated in a bitmap format, or image data may be generated in a JPEG (Joint Photographic Experts Group) format.

  In the above-described technique, the image data is compressed regardless of the data format of the image data generated by the application. Therefore, the image quality of the image data expanded by the image forming apparatus may be deteriorated. For example, in the case of an irreversible compression method such as the JPEG method, if the compression rate is increased, mosquito noise or the like is generated in the image, and the image quality is degraded.

  The present invention has been made in view of the above problems, and can transfer image data to an image forming apparatus without degrading image quality more than necessary according to the data format of image data generated by an application. The purpose is to obtain a computer program that can be used.

  In order to solve the above problems, the present invention is configured as follows.

The computer program according to the present invention includes: (a) a data compression processing unit capable of compressing image data output from an application by a lossless compression method and an irreversible compression method; and (b) a print request from the application. If there is, the data format of the image data output from the application is specified, the setting value of the image compression setting for the data compression at the time of image data transfer to the image forming apparatus is specified, and the data format is a bitmap format. In some cases, the data compression processing unit compresses the image data by the lossless compression method or the lossy compression method corresponding to the set value of the image compression setting, and the compressed image data is transferred to the image forming apparatus, If the format is compressed using the lossy compression method, regardless of the setting value of the image compression setting. , Without compression in the data compression processing section, to function as a control unit for transferring the image data output from an application to directly image forming apparatus. The data compression processing unit can compress the image data by the delta row method or the JPEG method, and when the data format is a bitmap format, the control unit sets the image compression setting among the delta row method and the JPEG method. If the data compression processing unit compresses the image data with the compression method corresponding to the value and the data format is JPEG format, the compression rate of the lossy compression method by the data compression processing unit is irreversible. Even when the compression rate is different from the compression rate when the image is compressed by the compression method, the image data output from the application is directly transferred to the image forming apparatus without being compressed by the data compression processing unit regardless of the set value of the image compression setting. Forward. The data compression processing unit makes the compression rate of the lossy compression method when compressing the image data higher than the compression rate of the lossless compression method.

Thereby, when the image data generated by the application is compressed by a specific lossy compression method, the image data is transferred without performing the compression process again. In other words, even when the lossless compression method is specified by the setting value of the image compression setting, if the image data from the application is already compressed with a specific lossy compression method, the compression with the lossless compression method is not performed. No re-compression by the lossless compression method is performed. Therefore, it is possible to transfer image data to the image forming apparatus without degrading image quality more than necessary. In addition, when the lossy compression method is selected based on the setting value of the image compression setting, the data transfer amount is reduced, so that the printing process is executed at high speed. On the other hand, when the lossless compression method is selected based on the setting value of the image compression setting, the data transfer amount increases, but image quality deterioration due to data compression / decompression does not occur.

The computer program according to the present invention, in addition to the above computer program, may be as follows. In this case, data indicating the compression method of the image data is included in the header of the image data.

  As a result, the image forming apparatus can appropriately decompress the image data in accordance with the compression method.

  According to the present invention, it is possible to obtain a computer program that can transfer image data to an image forming apparatus without degrading image quality more than necessary according to the data format of image data generated by an application.

FIG. 1 is a block diagram mainly showing a configuration of a terminal device installed with a driver program according to Embodiment 1 of the present invention. FIG. 2 is a flowchart for explaining processing by the driver program according to Embodiment 1 of the present invention. FIG. 3 is a diagram illustrating an example of a graphics details setting window.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram mainly showing a configuration of a terminal device installed with a driver program according to Embodiment 1 of the present invention. The terminal device 1 is, for example, a personal computer. The image forming apparatus 2 is connected to the terminal device 1 via a predetermined communication path (peripheral device interface cable, computer network, etc.). The image forming apparatus 2 is an apparatus having at least one of a printing function, an image reading function, and a facsimile transmission / reception function.

  The terminal device 1 includes an input device 11, a display device 12, a communication device 13, a data storage device 14, and a computer 15.

  The input device 11 is a device that detects a user operation and outputs it as an electrical signal. As the input device 11, a keyboard, a mouse, a touch panel, or the like is used.

  The display device 12 is a device that receives an electrical signal and displays an image corresponding to the electrical signal on a screen. A liquid crystal display or the like is used as the display device 12.

  The communication device 13 is a device that performs data communication with peripheral devices such as the image forming apparatus 2 via a predetermined communication path. As the communication device 13, a peripheral device interface, a network interface card, or the like is used.

  The data storage device 14 is a device that stores data and programs. In the first embodiment, the data storage device 14 includes a driver program 21 for the image forming apparatus 2, a plurality of application programs 22-1 and 22-2 that can use the driver program 21, and setting data for the driver program 21. 23 is stored. As the data storage device 14, a hard disk driver, a nonvolatile memory, or the like is used. The driver program 21 is an example of a computer program.

  The setting data 23 includes image compression settings. The image compression setting is a setting for data compression at the time of image data transfer to the image forming apparatus 2, and the setting value of the image compression setting indicates image quality priority or transfer speed priority. When the setting value of the image compression setting indicates image quality priority, this setting specifies a lossless compression method with a low compression rate. When the setting value of the image compression setting indicates transfer speed priority, this setting is used for high compression. A rate lossy compression scheme is specified.

  The computer 15 includes a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), etc. (not shown), loads various programs into the RAM, and executes them by the CPU, thereby realizing various processing units. It is a device to do.

  When the driver program 21 is executed by the computer 15, a driver 31 that is a processing unit that performs data transfer, data processing, and the like to the image forming apparatus 2 is realized. The driver 31 includes a control unit 41 and a data compression processing unit 42.

  When there is a print request from the application 32-i (i = 1, 2), the control unit 41 specifies the data format of the image data output from the application 32-i and compresses the image based on the setting data 23. When the setting value is specified and the data format is a bitmap format, the image data is sent to the data compression processing unit 42 by a compression method (lossless compression method or lossy compression method) corresponding to the setting value of the image compression setting. And the compressed image data is transferred to the image forming apparatus 2, and the data compression processing is performed regardless of the set value of the image compression setting when the data format is a format compressed by the lossy compression method. This is a processing unit that transfers the image data output from the application 32-i as it is to the image forming apparatus 2 without being compressed by the unit 42. The control unit 41 controls the communication device 13 to transfer image data.

  Note that the control unit 41 does not provide the data even when the compression rate of the lossy compression method by the data compression processing unit 42 is different from the compression rate when the data format by the application 32-i is compressed by the lossy compression method. When the format is a format compressed by the lossy compression method, the image data output from the application is formed as it is without being compressed by the data compression processing unit 42 regardless of the setting value of the image compression setting. Transfer to device 2.

  The data compression processing unit 42 is a processing unit capable of compressing image data output from the applications 32-1 and 32-2 by a lossless compression method and a lossy compression method. In this embodiment, the data compression unit 42 can compress data by the delta row method, which is one of the lossless compression methods, and the JPEG method, which is one of the lossy compression methods.

  The data compression processing unit 42 sets the compression rate of the irreversible compression method to be higher than the compression rate of the lossless compression method. Here, the compression rate is defined as, for example, (data size before compression−data size after compression) / data size before compression. For this reason, the higher the compression ratio, the smaller the data size after compression.

  The data compression processing unit 42 or the control unit 41 includes data indicating the compression method of the image data in the header of the image data. Thereby, the compression method is specified by referring to the data in the image forming apparatus 2, and the image data can be appropriately decompressed in accordance with the compression method.

  In addition, the application programs 22-1 and 22-2 are executed by the computer 15, thereby realizing the applications 32-1 and 32-2. Each of the applications 32-1 and 32-2 is a processing unit that performs processing for a specific purpose such as document creation and numerical calculation. The applications 32-1 and 32-2 can cause the image forming apparatus 2 to execute printing using the driver 31. When executing printing, the applications 32-1 and 32-2 generate image data for printing and pass it to the driver 31. Here, at that time, the application 32-1 generates image data in the bitmap format, and the application 32-2 generates image data in the JPEG format.

  The image forming apparatus 2 illustrated in FIG. 1 is a device such as a printer or a multifunction peripheral, and includes a control circuit 51, a communication device 52, and an arithmetic processing device 53.

  The control circuit 51 is a circuit that controls an electrophotographic print engine (not shown), for example, and prints an image on paper. The communication device 52 is a device capable of data communication with the communication device 13 of the terminal device 1.

  The arithmetic processing unit 53 is a computer, a digital signal processor, or the like, and implements a control unit 61, an image processing unit 62, and a data expansion processing unit 63. The control unit 61 is a processing unit that controls the control circuit 51 with image data after image processing. The image processing unit 62 is a processing unit that performs processing such as image enlargement / reduction and rotation on the image data as necessary in addition to rasterization and multi-value processing. The data decompression processing unit 63 is a processing unit that decompresses image data when compressed image data is received. Therefore, in the image forming apparatus 2, when the compressed image data is received by the communication device 52, the data decompression processing unit 63 identifies the compression method from the header of the image data, decompresses the image data, Thereafter, the image processing unit 62 appropriately performs image processing on the image data, and the control unit 61 causes the control circuit 51 to operate using the image data after the image processing to execute image printing.

  Next, the operation of the above apparatus will be described.

  FIG. 2 is a flowchart for explaining processing by the driver program 21 according to the first embodiment of the present invention.

  When the control unit 41 detects a print request from the application 32-1 or the application 32-2 (step S1), the control unit 41 specifies a setting value of the image compression setting at the time of data transfer based on the setting data 23 (step S2).

  Further, the control unit 41 specifies the data format of the image data output from the application 32-1 or the application 32-2 (step S3). The data format of the image data is specified based on the type of the application 32-1 or the application 32-2 that has requested printing and the content of the image data.

  Then, the control unit 41 determines whether or not the data format is a JPEG format (step S4).

  When it is determined that the data format is, for example, the bitmap format and not the JPEG format (step S4), the control unit 41 determines whether or not the setting value of the image compression setting in the setting data 23 indicates the transfer speed priority. (Step S5).

  When it is determined that the setting value of the image compression setting in the setting data 23 indicates the transfer speed priority, the control unit 41 causes the data compression processing unit 42 to compress the image data by the JPEG method (step S6), and after the compression. The image data is transferred to the image forming apparatus 2 via the communication device 13 (step S7).

  On the other hand, when it is determined that the setting value of the image compression setting in the setting data 23 does not indicate transfer speed priority (that is, when the setting value of the image compression setting in the setting data 23 indicates image quality priority), The control unit 41 causes the data compression processing unit 42 to compress the image data by the delta row method (step S8), and transfers the compressed image data to the image forming apparatus 2 via the communication device 13 (step S7).

  If it is determined in step S4 that the data format output from the application 32-i that has requested printing is the JPEG format, the control unit 41 directly transmits the image data in the JPEG format via the communication device 13. To the image forming apparatus 2 (step S7).

  As described above, when the data format of the image data from the application 32-i is the JPEG format, the driver 31 transfers the image data as it is regardless of the setting value of the image compression setting in the setting data 23.

  Here, input and change of the setting value of the image compression setting will be described.

  When a predetermined user operation is detected by the input device 11, the driver 31 causes the display device 12 to display a graphics detailed setting window. FIG. 3 is a diagram illustrating an example of a graphics details setting window. In the graphics details setting window, two radio buttons 101 and 102 for inputting setting values of image compression settings are displayed as image processing options.

  Only one of the two radio buttons 101 and 102 can be selected. When the radio button 101 is selected, the driver 31 sets the setting value of the image compression setting in the setting data 23 to a value indicating transfer speed priority, and when the radio button 102 is selected, The driver 31 sets the setting value of the image compression setting in the setting data 23 to a value indicating image quality priority.

  In this manner, the setting value of the image compression setting is determined by the graphical user interface according to the user operation, and is stored as the setting data 23.

  As described above, according to the above embodiment, when there is a print request from the application 32-i, the control unit 41 of the driver 31 specifies the data format of the image data output from the application 32-i. In addition, when the setting value of the image compression setting is specified and the data format is a bitmap format, the compression method corresponding to the setting value of the image compression setting (a lossless compression method such as a delta row method or an irreversible compression method such as a JPEG method) ), The data compression processing unit 42 compresses the image data, transfers the compressed image data to the image forming apparatus 2, and the data format is a format compressed in the lossy compression method (here, JPEG format). In this case, regardless of the setting value of the image compression setting, the data is not compressed by the data compression processing unit 42 and output from the application 32-i. Directly transferred to the image forming apparatus 2 to image data.

  Thus, when the image data generated by the application 32-i is compressed by a specific lossy compression method, the image data is transferred without performing the compression process again by the driver 31. That is, even when the lossless compression method is designated by the setting value of the image compression setting, if the image data from the application 32-i has been compressed by a specific lossy compression method, the compression by the lossless compression method is performed. Also, re-compression by the lossy compression method is not performed. Therefore, the image data can be transferred to the image forming apparatus 2 without deteriorating the image quality more than necessary. In that case, since the driver 31 does not perform compression processing, the image data can be transferred immediately, and the transfer time of the image data is shortened.

  The above-described embodiments are preferred examples of the present invention, but the present invention is not limited to these, and various modifications and changes can be made without departing from the scope of the present invention. is there.

  For example, in the above embodiment, the delta row method is used as the lossless compression method, but another method such as a run length method may be used. Moreover, in the said embodiment, although the JPEG system is used as a lossy compression system, you may use another system.

  In the above embodiment, the image data transferred to the image forming apparatus 2 is used for printing, but may be used for other functions (facsimile transmission and the like).

  The present invention can be applied to a device driver for an image forming apparatus such as a printer, a copier, or a multifunction peripheral.

2 Image forming apparatus 15 Computer 21 Driver program (an example of a computer program)
32-1 and 32-2 Application 41 Control unit 42 Data compression processing unit

Claims (2)

Computer
A data compression processing unit that can compress image data output from an application using a lossless compression method or a lossy compression method, and when there is a print request from the application, the data format of the image data output from the application is specified. In addition, the setting value of the image compression setting for the data compression at the time of transferring the image data to the image forming apparatus is specified, and when the data format is a bitmap format, the setting value of the image compression setting is supported. The data compression processing unit compresses the image data by the lossless compression method or the lossy compression method, transfers the compressed image data to the image forming apparatus, and the data format is compressed by the lossy compression method. The data compression processing unit does not compress the data regardless of the setting value of the image compression setting. And functioning as a control unit that directly transfers the image data output from the application to the image forming apparatus ,
The data compression processing unit can compress the image data by a delta row method or a JPEG method,
When the data format is a bitmap format, the control unit compresses the image data into the data compression processing unit using a compression method corresponding to a setting value of the image compression setting, among a delta row method and a JPEG method. When the data format is JPEG format, the compression rate of the lossy compression method by the data compression processing unit is the compression rate when the data format by the application is compressed by the lossy compression method. Even when different from the above, regardless of the setting value of the image compression setting, the image data output from the application is directly transferred to the image forming apparatus without being compressed by the data compression processing unit,
The data compression processing unit makes the compression rate of the lossy compression method higher than the compression rate of the lossless compression method when compressing the image data;
A computer program characterized by the above. Claim 1 Symbol placement computer program data indicating the compression method of the image data is characterized in that it is included in a header of the image data.

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