KR20000013000A - Display bitmap printer system and method using compression - Google Patents

Abstract

PURPOSE: A display bitmap printer system and method using compression is provided to supply fast printing result using extend procedure which extends display bitmap format to printer display bitmap. CONSTITUTION: The display bitmap printer system and method comprises an application program, a printer driver, a video controller and a engine controller. In the display bitmap printer system and method, the application program organize a data to device independent bitmap(DIB). The printer driver makes a gray table for an image data and transforms device independent color image to image data of device dependent bitmap(DDB) type and zoom in according to printer resolution to y axis direction and compress and transmits a data. The video controller zoom in data to x-axis direction and un-compress image data of DDB type and zoom in to x axis direction. The engine controller drives engine and prints the image data.

Description

Printer system and method for quickly outputting display bitmap using compression

The present invention relates to a printer system, and more particularly, to convert a display bitmap into a printer bitmap through a laser printer and to divide the series of jobs when printing, thereby rapidly displaying a display bitmap using compression, which reduces the burden on the host computer. It relates to a printer system and a method for outputting.

In general, a laser printer converts a display bitmap data of data to be printed generated by an application program into a printer bitmap through a printer driver of a host computer, receives the data, and prints the same through a printer engine.

Referring to this process with reference to Figure 1, first, the application program 11 of the host computer 10 has a display bitmap format and color information of the print data, in general, the display bitmap format is a device-independent bitmap (Device Independent Bitmap).

On the other hand, the printer driver 12 receives the display bitmap format and color information from the application program 11 and performs color mapping with a color mapping table (not shown) that it has, and then the video controller 22 of the printer 20. ) Expands into a printer bitmap format that can be represented.

In general, the printer driver 12 extends the 72 DPI display bitmap format delivered from the application 11 to the standardized printer bitmap formats of 75, 150, 300, and 600 DPI depending on the printer DPI.

After the host computer 10 expands the display bitmap format to the printer bitmap format by the printer driver 12, the host computer 10 transmits the expanded printer bitmap format data to the laser printer 20 through the print data transmission unit 13. It transfers to the print data receiver 21.

Meanwhile, the video controller 22 of the laser printer 20 receives the extended printer bitmap format data through the print data receiver 21 and then performs half toning to set the printer bitmap format data to 0 ,. The engine controller 23 is transmitted to the engine controller 23 in the form of 1, and the engine controller 23 drives and prints the engine 24 according to the transmitted information of the 0 and 1 forms.

According to this conventional printing method, the printer driver 12 of the host computer 10 formats the 72 DPI display bitmap format delivered from the application 11 according to the printer DPI of 75, 150, 300, and 600 DPI. Since the printer driver 12 existing on the host computer is fully responsible for extending the printer bitmap format, the problem of reducing the efficiency of the host computer in performing the display bitmap expansion operation.

In addition, the conventional printing method has a problem in that the transfer time from the host computer 10 to the printer 20 is consumed because the amount of printer bitmap format data extended by the printer driver 12 is large.

Accordingly, it is an object of the present invention to overcome the problems of the prior art caused by the printer driver performing the expansion of the display bitmap format to a printer bitmap format suitable for a video controller on a host computer. The process of extending the format is divided between the printer driver and the video controller so as to reduce the burden on the host computer due to the expansion of the bitmap format.

Another object of the present invention is to reduce the burden of transmitting a print bitmap from a host computer to a printer.

1 shows a typical printer environment,

2 illustrates a printer system for quickly outputting a display bitmap using compression according to the present invention.

3 illustrates a method of quickly outputting a display bitmap using compression according to the present invention;

4 illustrates binarizing an enlarged image using an 8x8 halftoning table in accordance with the present invention.

<Description of Symbols of Major Parts of Drawings>

100: host computer 110: application

120: printer driver 121: DIB receiver

122: gray table creation unit 123: color mapping unit

124: Y-axis enlargement unit 125: Compression unit

130: print data transmission unit 200: printer

210: print data receiver 220: video controller

221: decompression unit 222: X-axis expansion unit

223: half toning unit 230: engine controller

240: engine

According to an aspect of the present invention for achieving the above object, the application program of the host computer is configured to form a device independent bitmap (DIB) through a GDI method that supports the data to be printed in Windows printer driver The printer driver creates a gray table of the transmitted image data and changes the device-independent color image into image data in the form of a device dependent bitmap (DDB). The printer receives the image data in the form of a device-dependent bitmap (DDB), which is enlarged and compressed on the Y-axis to the printer, and compressed on the Y-axis from the host computer, to the resolution of the image data through the video controller. Decompress and enlarge the X axis to match the resolution of the printer. Binarizing the transfer to the engine controller for the printing, and the engine controller that drives the engine according to the binarized image data expanding rapidly output the display bitmaps using compression printer which performs printing system is disclosed.

Preferably, the printer driver receives device data of the device independent bitmap form from the application program through the DIB receiver and uses the RGB color table present in the header portion of the device independent bitmap image received through the gray table generator. A gray table is created, and the device-independent color image is changed into image data in a device dependent bitmap (DDB) form according to the gray table created through the color mapping unit. In addition, the Y-axis enlargement unit enlarges the Y-axis image data in the form of device-dependent bitmap (DDB) to fit the resolution of the printer, and the Y-axis enlarged device-dependent bitmap (DDB) form the image data in the compression unit. Compress.

Preferably, the video controller decompresses the compression of the image data in the form of a device-dependent bitmap (DDB) form by decompressing and decompressing the image data transmitted from the host computer to the Y-axis received through the print data receiving unit. After the enlarged image data is enlarged on the X-axis to match the resolution of the printer through the X-axis enlargement unit, the half-toning unit binarizes the enlarged image data by using a halftone table.

According to another aspect of the present invention, in a printer printing method for receiving and printing print data transmitted from a host computer, a device-independent bitmap of data to be printed on the host computer side through a predetermined means DIB), a gray table for the configured image data, and the device-independent color image in the form of a device dependent bitmap (DDB) through the created gray table. The image data is changed into image data, the image data in the form of the device-dependent bitmap (DDB) is expanded on the Y-axis, and the enlarged image data is compressed and transmitted to the printer. On the other hand, the printer side decompresses the compressed image data enlarged on the Y axis, and decompresses the decompressed image data on the X axis to drive the engine according to the binary enlarged image data. A method of rapidly outputting a display bitmap using compression to perform printing is disclosed.

Hereinafter, the objects, features, and advantages of the present invention described above will be described in more detail with reference to the preferred embodiments of the present invention shown in the accompanying drawings.

The terms to be described below are terms defined in consideration of functions in the present invention, and may vary according to the intention or custom of a person skilled in the art, and the definitions should be made based on the contents throughout the specification.

A printer system for quickly outputting a display bitmap using compression according to the present invention will be described with reference to FIG. 2.

First, the application program 110 of the host computer 100 configures a device independent bitmap (DIB) format through a GDI method supported by Windows and transmits the data to the printer driver 120. The printer driver 120 creates a gray table for the transmitted image data, and changes the device-independent color image into image data in the form of a device dependent bitmap (DDB). Magnification and compression on the Y-axis to fit the resolution is transmitted to the printer 200 through the print data transmission unit 130.

On the other hand, the printer 200 receives the image data in the form of a device-dependent bitmap (DDB) expanded and compressed on the Y-axis from the host computer 100 through the print data receiver 210, and receives the video controller 210. Decompresses the image data and enlarges the X-axis to fit the resolution of the printer and transmits the binarized image to the engine controller 230 for printing. The engine controller 230 drives the engine 240 according to the binarized enlarged image data. Drive to print.

At this time, the printer driver 120 receives the image data of the device independent bitmap form from the application program through the DIB receiving unit 121, and the header of the device independent bitmap image received through the gray table creating unit 122 Create a gray table using the RGB color table existing in the part, and device-dependent bitmap (DDB) to display a device-independent color image according to the gray table created through the color mapping unit 123. Change to image data of type.

In addition, the Y-axis enlarger 124 enlarges the Y-axis image data in the form of a device-dependent bitmap (DDB) to match the resolution of the printer, and the Y-axis enlarged device-dependent bitmap through the compressor 125. (DDB) compresses image data.

Meanwhile, the video controller 220 decompresses the compression of the image data in the form of a device-dependent bitmap (DDB), which is transmitted from the host computer 100 and expanded on the Y axis received through the print data receiver 210. After decompressing through the unit 221 and expanding the decompressed image data through the X-axis enlarger 222 to match the resolution of the printer, the half-toning unit 223 uses the enlarged image data as shown in FIG. 4. Binarize using a halftone table as follows.

Hereinafter, the operation of the printer system for quickly outputting a display bitmap using compression according to the present invention will be described with reference to FIGS. 2 to 4.

When a print command is executed, the application program 110 of the host computer 100 configures the print data as image data in a device independent bitmap (DIB) format through Windows Graphic Descript Interpret (GDI). Transfer to step 120 (step: S310).

The printer driver 120 receiving the transmitted image data through the DIB receiver 121 uses the RGB color table present in the header portion of the device-independent bitmap (DIB) image by the gray table generator 122. Create a gray table (step: S320).

Preferably, the process of creating a gray table using an RGB color table uses an RGB color table provided by Microsoft's Windows (MS-Windows), which is a general technique, and Microsoft's Windows (MS-windows). Anyone with a normal knowledge of) can easily create gray tables.

After the gray table is created, the actual color image is changed into image data in the form of a device dependent bitmap (DDB) using the gray table (step S330).

Preferably, the device dependent bitmap (DDB) may vary depending on the state of the device independent bitmap (DIB) image, but is represented by 256 gray when the device independent bitmap (DIB) image state is 256 colors or more.

The process of converting a device independent bitmap (DIB) image into a device dependent bitmap (DDB) is called color mapping and is performed by the color mapping unit 123.

The printer driver 120 converts the device independent bitmap (DIB) image into device-dependent bitmap (DDB) image data through color mapping, and then converts the changed image data into the Y-axis enlarger 124. Zoom to the Y-axis to fit the printer DPI through (step S340).

After the image data is enlarged on the Y axis through the Y axis enlarger 124, the image data enlarged on the Y axis is compressed by the compression unit 125 (step S350).

After compressing the image data enlarged on the Y-axis, the host computer 100 transmits the image data enlarged on the Y-axis to the printer 200 through the print data transmission unit 130 (step: S360).

The video controller 220 of the printer 200, which receives the image data enlarged on the Y-axis transmitted from the host computer 100 through the print data receiver 210, decompresses through the decompressor 221, The image data decompressed by the X-axis enlargement unit 222 is enlarged by the X-axis according to the resolution of the printer 200 (step: S370).

Preferably, if the display bitmap is 72 DPI and the printer DPI is 600, then the gray image is plotted on the X axis. It scales by as much as possible, even if it is not already a constant multiplier using a scaling scaling algorithm.

After the X-axis / Y-axis enlarged to receive the device-dependent bitmap (DDB) gray image data to match the resolution of the printer 200, the half-toning unit 223 of the video controller 220 is as shown in FIG. The enlarged gray image data is converted into a bitmap image consisting of 0s and 1s by comparing the value of the halftone table with the enlarged gray image value through an 8 × 8 halftone table. (Step: S380).

Preferably, the binarization process of converting the enlarged image into a bitmap image consisting of zeros and ones is performed by moving the halftone table and using an error diffusion algorithm, which has a general knowledge of image processing. This is a common technique for humans, so description is omitted.

The bitmap image modified through the above-described process is transmitted to the engine controller 230 and is printed through the engine 240 under the control of the engine controller 230 (steps S390 and S400).

Preferably, the video controller 220 according to the present invention generates bitmap data to be transmitted to the engine in advance, stores it in a compressed form, and decompresses the compression at the moment when the engine 240 substantially prints. A method of transmitting and printing to the engine 240 may be used.

As described above, according to the present invention, the process of extending the display bitmap format to the printer bitmap format can be appropriately divided between the printer driver and the video controller, thereby reducing the burden on the host computer due to the expansion of the bitmap format. By optimizing the data generated by the driver, it reduces the amount of data sent to the printer, thereby providing a quick output result to the user.

Although the preferred embodiments of the present invention have been described in detail above, those skilled in the art will appreciate that the present invention may be modified without departing from the spirit and scope of the invention as defined in the appended claims. It will be appreciated that modifications or variations may be made. Therefore, changes in the future embodiments of the present invention will not be able to escape the technology of the present invention.

Claims (8)

An application program for configuring data to be printed in a device independent bitmap (DIB) form through a predetermined means; Create a gray table for the configured image data and change the device-independent color image into image data in the form of device dependent bitmap (DDB) to the Y-axis according to the resolution of the printer. A printer driver for enlarging, compressing, and transmitting the image; A video controller for decompressing image data in the form of a device-dependent bitmap (DDB) compressed by expanding the transmitted Y-axis and expanding and binarizing the X-axis according to the resolution of a printer; And a printer system for rapidly outputting a display bitmap using compression, including an engine controller for driving the engine according to the binarized enlarged image data. The method of claim 1, wherein the printer driver, A DIB receiver configured to receive image data in a device independent bitmap form from the application program; A gray table creating unit which creates a gray table using an RGB color table present in a header portion of the received device independent bitmap image; A color mapping unit for converting the device-independent color image into image data in a device dependent bitmap (DDB) form according to the created gray table; A Y-axis magnifying unit configured to enlarge the Y-axis of the image data in the form of a device-dependent bitmap (DDB) according to a resolution of a printer; And a compression unit configured to compress the image data in the Y-axis-enlarged device-dependent bitmap (DDB) form. The method of claim 1, wherein the video controller, A decompression unit configured to decompress image data in the form of a device-dependent bitmap (DDB) compressed by expanding the Y-axis; An X-axis magnifying unit configured to enlarge the decompressed image data to an X-axis in accordance with a resolution of a printer; And a printer system for quickly outputting a display bitmap using compression including a half-toning unit for binarizing the enlarged image data through a halftone table. The method of claim 3, wherein the half toning unit, The halftone table is moved by comparing the value of the halftone table with the enlarged gray image value through an 8 × 8 halftone table, and binarized using an error diffusion algorithm. A printer system for quickly outputting display bitmaps using compression. The method of claim 1, wherein the predetermined means, A printer system for quickly outputting a display bitmap using compression, characterized by Windows Graphic Descript Interpret (GDI) means. The method of claim 1, wherein the video controller, The bitmap data to be transmitted to the engine is generated in advance, stored in a compressed form, and then decompressed and transmitted to the engine for printing at the moment when the engine substantially prints. Printer system for quickly printing display bitmaps. In the printing method of a printer for receiving and printing print data transmitted from a host computer, On the host computer side Configuring the data to be printed in the form of a device independent bitmap (DIB) through a predetermined means; Creating a gray table for the constructed image data; Changing the device independent color image into image data in a device dependent bitmap (DDB) form through the created gray table; Enlarging the modified device-dependent bitmap (DDB) image data on a Y-axis; Compressing the enlarged image data and transmitting the compressed image data to the printer; Decompressing the compressed image data enlarged on the Y axis at the printer side; Binarizing the decompressed image data on an X axis; A method of rapidly outputting a display bitmap using compression, the method comprising: driving an engine according to the binarized enlarged image data to perform printing. The method of claim 7, wherein the predetermined means, A method of quickly outputting a display bitmap using compression, characterized by Windows Graphic Descript Interpret (GDI) means.