JPH08123633A - Color image printing system - Google Patents

Abstract

PURPOSE: To increase the processing speed by eliminating repeated image processing. CONSTITUTION: This color image printing system which transfers color image data to be printed out that are generated by a host computer 1 to a printer 3 in band units, converts the transferred data into print data for print output through the color processing of the printer 3, and expands the data on a band memory 33 and then outputs the data transfers the print data expanded on the band memory 33 to the side of the host computer 1 through two-way interfaces 21 and 18. The host computer 1 stores a hard disk 12 with the transferred print data in the band units and when the same print data are printed by plural sheets, the print data for the 2nd and succeeding sheets are transferred to a print output device side in the band units from the band memory 2 and then outputted on the printer 3 without the color processing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color image printing system for converting color image data generated by a host device into print data which can be printed out and outputting the print data from the print output device.

[0002]

2. Description of the Related Art CAD data generated by a CAD system, image data read by an image scanner, etc. are a set of drawing commands for a plotter,
Since these are compressed raster data, it is necessary to convert the data format to a printable format when outputting them with a raster printer or the like. In particular, in the case of printing a color image, the color image data on the host computer is subjected to processes such as rasterization, edge emphasis, enlargement / reduction, color correction, binarization, RGB → CMYK conversion, etc., and the color image is output. .

On the other hand, there are various types of recording methods adopted in a printer which is a print output device, such as ink jet, thermal, electrostatic, electrophotographic, etc. even if only the raster method is used.
Among them, in the case of a high-speed recording method such as thermal, electrostatic, or electrophotographic, print data of full bit map rasterized in advance is collectively transferred to the printer engine. However, in this case, it is necessary to provide the printer with a large-capacity buffer memory, and there is a problem that the printer becomes expensive. On the other hand, in the case of a relatively low-speed printer using an inkjet head or the like, the capacity of the buffer memory of the printer can be increased by transferring each process after rasterization to the printer engine while executing each process of each band of a predetermined width. Can be suppressed to the bandwidth, and a comparatively inexpensive printer can be provided.

[0004]

However, in the conventional band-type color image printing system described above, since the buffer memory on the printer side does not have a capacity for one image data, one page of data is output. In the meantime, the band memory is sequentially rewritten. Therefore, when the same image data is repeatedly printed, the same image processing as that for the first sheet has to be repeated for the second and subsequent sheets, and there is a problem that it takes time to complete printing.

The present invention has been made to solve such a problem, and in a color image printing system of band type, color image printing capable of omitting redundant image processing and improving processing speed. The purpose is to provide a system.

[0006]

A color image printing system according to the present invention is a print data for print output by color-processing color image data to be printed out generated on the host side in band units of a predetermined width. In the color image printing system which converts the print data into a band memory provided in the print output device and then outputs the print data, the print data expanded in the band memory on the print output device side is output to the host side via a bidirectional interface. Print data transfer means for transferring to the host side, storage means for storing the print data transferred to the host side by the printer data transfer means, and printing of the same print data on a plurality of sheets Is
The print data stored in the storage means is transferred to the print output device side in band units, and is output from the print output device without undergoing the color processing.

[0007]

According to the present invention, the print data once expanded in the band memory by the print output device is transferred to the host side through the bidirectional interface and stored in the storage device provided in the host side. When printing the same print data on a plurality of sheets, for the print data for the second and subsequent sheets, the print data stored in the storage means is transferred to the print output device side in band units, and the overlapping color Since the print output is performed immediately without executing the processing, it is possible to greatly reduce the time until the completion of printing.

In a system that outputs a full-color image as a pseudo-color image, for example, 24 bits / dot
Rasterized data of 3bit / do by color processing
Since the print data is converted into the print data of t, the data transfer amount for the second and subsequent sheets is also significantly reduced, and the printing speed can be improved accordingly.

[0009]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a functional block diagram showing the configuration of a color image printing system according to an embodiment of the present invention. This system includes a host computer 1, an image scanner 2 connected to the host computer 1, and a printer 3 that receives image data from the host computer 1 via a bidirectional interface such as a SCSI interface and performs print processing. It is configured.

A color original such as a photograph is read by the scanner 2 and stored in the hard disk 12 under the control of the scanner driver 11 of the host computer 1. The synthesizing / editing processing unit 13 is composed of a CPU and an image synthesizing / editing application program, displays the read color image data on a display device 14 such as a CRT, a liquid crystal display, and an input device 15 such as a keyboard and a mouse. In accordance with the operation of, characters and other color images are appropriately combined and edited. The color image data including the edited character code is rasterized in a band unit of a predetermined width by a drawing processing unit 16 such as an image processor, and under the control of the printer driver 17, a bidirectional interface (hereinafter, I / F). 18)
The data is transferred to the printer 3 side in units of bands via the.

On the printer 3 side, the transferred color image data in band units is supplied to a printer controller 22 via an I / F (bidirectional) 21. The printer controller 22 stores the color image data of one band received via the I / F 21 in the reception buffer 31, and then, in the color processing unit 32, edge emphasis and enlargement / enlargement
Reduction, color correction, binarization (pseudo color conversion), RGB → C
Convert to print data by performing each process of MYK conversion,
The data is expanded in the band memory 33 having a data storage capacity for one band. The print data expanded in the band memory 33 is supplied to the printer engine 23 and printed out.

The print data for one band stored in the band memory 33 is supplied to the print data transmission processing section 34 and stored in the transmission buffer 35 under the control of the print data transmission processing section 34. Later, I /
It is transferred to the host computer 1 side via F21.
On the host computer 1 side, the print data for one band transferred from the printer 3 is sent to the printer driver 17
It is stored in the hard disk 12 via. The printer driver 17 reads out the print data stored in the hard disk 12 in band units and transfers the print data to the printer 3 side for the second and subsequent print outputs. Printer 3
When the received data is print data, the transferred print data is directly expanded in the band memory 33 without activating each process in the color processing unit 32. In addition to the above configuration, the printer 3 is provided with an operation panel 24 for setting the print mode of the printer 3 offline and a display unit 25 for displaying the print mode and the like.

FIG. 2 is a diagram showing color image data to be printed out. As shown in the figure, the color image data is divided into a plurality of bands corresponding to the capacity of the band memory 33 of the printer 3 and transferred and processed. In this embodiment, it is assumed that one color image data is divided into four bands and processed. The rasterizing process in the host computer 1 is a process of expanding original image data described in, for example, a page description language into high resolution bit image data, and the transfer data has 8 bits (24 bits / dot) for each pixel of RGB. As expressed, it is full-color data representing approximately 16.7 million different colors.

Of the color processing for the rasterized data transferred to the printer 2, the edge emphasis processing is performed using, for example, a Gaussian filter or the like. The color correction process corrects the difference between the numerical color expressed inside the computer and the color actually output by the printer, that is, a slight color shift caused by the characteristic difference between the two devices, and is prepared in advance. This is a process for replacing the color of the pixel by referring to the color matching table with the data of the pixel image. The binarization process converts a pixel image expressed in full color into a pseudo full color image. For example, white, cyan, magenta, yellow,
Each pixel of the rasterized data is reconstructed so that it looks like a full color by combining eight colors of black, red, green and blue. In this binarization processing, a known pattern dither method, error diffusion method, or the like is used. RGB
In the CMYK conversion process, the color of each pixel expressed in red, green, and blue obtained by the binarization process is converted into four ink colors of cyan, magenta, yellow, and black that can be output by the printer. As a result, the obtained print data becomes data represented by 3 bits / dot, and the information amount is compressed to about 1/8 of the data before transfer.

FIG. 3 shows a printer driver 17 of the host computer 1 for printing only one copy of a color image.
It is a flowchart which shows the process of. When printing only one copy of the color image, the rasterized data may be transferred to the printer 3 in sequence from the first band to the fourth band (S1, S4, S5) and as soon as the printer is ready (S2). (S3).

FIG. 4 is a flow chart showing the processing of the printer driver 17 of the host computer 1 when printing a plurality of color images. The printing process (S11) for the first sheet is almost the same as the process shown in FIG. 3 described above (S12 to S14, S16, S17), but in the case of printing a plurality of copies, the rasterized data of each band is used. After transferring to the printer 3, the print data processed by the printer 3 is received from the printer 3 and stored in the hard disk 12 (S15). And 2
The print processing for the first and subsequent sheets is the same as the hard disk 1
The small-capacity print data stored in 2 may be read from the hard disk 12 for each band and transferred to the printer 3 (S18 to S23).

Which of the single-sheet printing in FIG. 3 and the multiple-sheet printing in FIG. 4 is to be executed is determined by the printer driver 17 based on the information on the number of copies designated by the operator through the user interface incorporated in the printer driver 17. Just make a decision.

According to this system, for the print output of the second and subsequent printers 3 of the same image data, the time until the completion of printing can be shortened by the amount that the processing in the color processing unit 32 can be omitted. Further, since the information amount of the print data of the second and subsequent sheets is significantly smaller than that of the rasterized data of the first sheet, the time required for the transfer of the second and subsequent sheets is shortened.

Although the color processing is executed on the printer 3 side in the above embodiment, all or part of the color processing may be executed on the host computer 1 side. Further, the sharing of the processing performed by the host computer 1 and the processing performed by the printer 3 may be adaptively changed according to the processing statuses of the host computer 1 and the printer 3.

[0020]

As described above, according to the present invention, the print data once expanded in the band memory in the print output device is transferred to the host side through the bidirectional interface and is provided in the host side. While storing in the storage device,
When printing the same print data on a plurality of sheets, for the print data for the second and subsequent sheets, the print data stored in the storage means is transferred to the print output device side in band units, thereby overlapping the duplicated color. Since the print output is performed immediately without executing the process, it is possible to significantly reduce the time required to complete the print.

[Brief description of drawings]

FIG. 1 is a functional block diagram showing a configuration of a color image printing system according to an embodiment of the present invention.

FIG. 2 is a diagram for explaining color image data printed by the system.

FIG. 3 is a flowchart showing a process of a printer driver when printing one copy of a color image in the system.

FIG. 4 is a flowchart showing a process of a printer driver when printing a plurality of color images in the system.

[Explanation of symbols]

1 ... Host computer, 2 ... Image scanner, 3 ...
Printer, 11 ... Scanner driver, 12 ... Hard disk, 13 ... Compositing / editing processing unit, 14 ... Display device, 15 ... Input device, 16 ... Drawing processing unit, 17 ... Printer driver, 18, 21 ... Bidirectional interface, 22
... printer controller, 23 ... printer engine, 2
4 ... Operation panel, 25 ... Display unit, 31 ... Reception buffer,
32 ... Color processing unit, 33 ... Band memory, 34 ... Print data transmission processing unit, 35 ... Transmission buffer.

Claims (1)

[Claims] 1. A color image data to be printed out, which is generated on the host side, is color-processed in band units of a predetermined width to be converted into print data for printout, and is stored in a band memory provided in a printout device. In a color image printing system for expanding and then outputting, print data transfer means for transferring the print data expanded in the band memory on the print output device side to the host side via a bidirectional interface, and the printer data transfer means. Storage means for storing the print data transferred to the host side by the above, and when printing the same print data for a plurality of sheets, for the print data for the second and subsequent sheets, the print data stored in the storage means is divided into band units. To the print output device side, and the print output is performed without going through the color processing. A color image printing system characterized by outputting from a pressure device.