JP2003264694A - Image processing device - Google Patents

Abstract

(57) [Problem] To provide an image processing apparatus capable of improving image quality at the time of printout by selecting an optimum printer γ based on a document determination signal. A type of input image is determined in an image processing apparatus that compresses an input image signal by a compression unit, stores the image signal in an image storage unit, decompresses an image signal extracted from the image storage unit by a decompression unit, and outputs the image. When an image is stored in the image storage unit, a document determination signal from the document determination unit and an input image signal are stored in combination.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing apparatus such as a color copying machine or a color printer, and more particularly to an image processing apparatus for accumulating an input image signal and outputting the accumulated image.

[0002]

2. Description of the Related Art Japanese Unexamined Patent Publication No. 2000-324338 exists as a conventional technique related to an image processing technique of accumulating an input image signal and outputting the accumulated image. The technique disclosed in this publication is for determining the type of a document based on an image signal input from a scanner.

[0003]

In a conventional color copying machine, RGB signals read by a scanner reading device are subjected to image processing such as edge enhancement and moire removal, and then converted into color material signals YMC. is doing. Further, after black plate (K) generation and undercolor removal are performed, characteristics of the input image, for example, a printer γ correction for a copy original in the case of a copy original, a printer γ correction for a character in the case of a character original,
The charged photoconductor is exposed by the laser light modulated with the gradation-processed data to form an image of each color.

Further, when the CMYK signals after color conversion are stored in a hard disk or the like and the stored image in the hard disk is reused and printed out after a lapse of time, the image data is encoded when the image data is stored. It is compressed and compressed to reduce the data capacity.

For example, considering a color copy image output by a copying machine as an input original, the copied original is output on paper with a yellow tracking pattern added to identify illegal copying. When this paper output is read by a scanner, the added yellow tracking pattern is also read as a document.

The input RGB image signal is filtered, and the color-converted CMYK signal is compressed and stored. When the accumulated image is expanded and reused, there is only information of image data, and even if the accumulated image is a copy original, it cannot be known.In normal copying, the user specifies the copy mode. Since it is not possible to perform the printer γ correction for the copy original as in the case of copying by using the copy method, the image quality may be deteriorated as compared with the normal copy operation. Further, in the case of inputting a copy document, even if the tracking pattern has already been printed, it may occur that an unsightly image is generated by further adding the tracking pattern and outputting.

Therefore, according to the present invention, when the input image signal is once stored and reused, the user does not need to specify it, the type of the original is automatically discriminated, and the discriminated signal is added to the image data. The accumulated image and the original judgment signal are expanded, and the optimum printer γ is calculated based on the original judgment signal.
It is an object of the present invention to provide an image processing apparatus capable of improving the image quality at the time of printing out by selecting.

Further, by eliminating the need for the user to directly specify what kind of original document is to be input during image storage, the load on the user is reduced, and when the stored image is reused, appropriate image processing is performed and printing is performed. An object is to provide an image processing device.

Further, when the stored original determination signal indicates a copy original, an image processing apparatus capable of improving output image quality by outputting without adding a new tracking pattern when printing out The purpose is to provide.

[0010]

In order to achieve the above-mentioned object, the invention according to claim 1 compresses an input image signal by a compression section, accumulates it in an image accumulation section, and extracts an image signal from the image accumulation section. In the image processing apparatus for decompressing the image by the decompression unit and outputting the image, the document determination unit for determining the type of the input image is provided, and when the image is stored in the image storage unit, the document determination signal from the document determination unit and the input image are input. The most main feature is an image processing device that stores the combined signal.

According to a second aspect of the present invention, a main feature of the image processing apparatus according to the first aspect is that the printer has a printer γ section for selecting an optimum γ table and outputting an image based on the original determination signal. And

According to a third aspect of the present invention, when the original determination signal expanded from the image storage unit indicates a copy original, the original determination signal is output without adding a new tracking pattern. The image processing apparatus described in 1 is a main feature.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of an image processing apparatus according to an embodiment of the present invention. FIG. 2 is a diagram showing signals stored in the memory. As shown in FIG. 1, the image processing apparatus includes a document determination unit 1, a filter processing unit 2, a color conversion unit 3, a compression unit 4, a memory 5, an expansion unit 6, and a printer γ unit 7.
Equipped with.

An original is read by a scanner reading device to obtain RGB signals as input image data. The RGB signals are input to the document determination unit 1 and a filter processing unit 2 including a smoothing filter that performs a smoothing process for removing moire and an emphasis filter that emphasizes character edges.

The output of the filter processing unit 2 is input to a color conversion unit 3 which converts an RGB signal into a CMYK signal, and a CM is supplied.
Converted to YK signal. This CMYK signal and the original determination signal from the original determination unit 1 (for example, “1” copy original,
“2”: signal indicating that the document is a character document) is sent to the compression unit 4.

Here, the document determining section 1 is, for example, disclosed in
No. 000-324338, and FIGS.
The document type determination method as shown in FIG.
To briefly explain this method, the type of original such as a copy original or a character original is determined from the input RGB signals.

The compression unit 4 compresses the CMYK signals,
It is stored in the memory 5 together with the document determination signal. For example, in FIG.
As described above, the CMYK compressed data may be attached with a fixed-length bit header and stored. The above is the procedure for writing to the memory.

The compressed data and the original determination signal read from the memory 5 are separated into compressed data and the original determination signal in the expansion section 6, and the compressed data is expanded and converted into a CMYK signal and sent to the printer γ section 7. .

FIG. 3 is an internal block diagram showing a first example of the printer γ section. The expanded CMYK signal and the original determination signal are input from the memory 5. CMYK signals are processed by different printer γ processing units 11-1 and 11-2 ...
11-n.

The processing units 11-1, 11-2 to 11-n perform different printer γ processing, and the processing unit 11-1
Performs processing using the printer .gamma. Table for copy documents, the processing unit 11-2 performs processing using the printer .gamma. Table for characters, and the processing unit 11-n performs processing using another printer .gamma. The original determination signal is an output selection signal of the multiplexer 12 which selects which of the CMYK signals subjected to different printer γ processing is used.

For example, when the original determination signal is "1", that is, when the original is a copy original, the CMYK signals processed by the processing section 11-1 for character originals are output from the multiplexer 12, and the determination signal is "2". That is, in the case of a character original, the CMYK processed by the copy original processing unit 11-2
The signal is output from the multiplexer 12. In this way, C processed by the optimum printer γ in accordance with the original determination signal
The MYK signal is sent to the output and the image formation for each color is performed.

FIG. 4 is an internal block diagram showing a second example of the printer γ unit. By passing the original determination signal together with the CMYK output after the printer γ processing as shown in FIG. 4, when the determination signal is a copy original, it is an original to which a tracking pattern has already been added. Can be prevented from being added.

[0023]

As described above, according to the first aspect of the present invention, since the original determination signal and the input image data are stored at the time of storing the image, the type of the image data when the image data is expanded later. Can be judged.

According to the second aspect of the present invention, the optimum printer γ can be selected according to the document determination signal, so that the image quality at the time of printing can be improved.

According to the third aspect of the present invention, if the original determination signal indicates a copy original, a new tracking pattern can be added to prevent image formation. Therefore, the image quality at the time of printout can be improved. Can be planned.

[Brief description of drawings]

FIG. 1 is a block diagram of an image processing apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing signals stored in a memory.

FIG. 3 is an internal block diagram showing a first example of a printer γ unit.

FIG. 4 is an internal block diagram showing a second example of a printer γ unit.

[Explanation of symbols]

1 Document judgment section 2 Filter processing unit 3 color converter 4 Compressor 5 memory (image storage) 6 Extension part 7 Printer γ section

Claims (3)

[Claims] 1. An image processing apparatus for compressing an input image signal in a compression unit, storing the image signal in an image storage unit, and expanding an image signal extracted from the image storage unit in an expansion unit to output an image. An image processing apparatus comprising a document determination unit for determining, and when storing an image in the image storage unit, a document determination signal from the document determination unit and the input image signal are stored in combination. 2. An optimum γ based on the original determination signal.
The image processing apparatus according to claim 1, further comprising a printer γ unit for selecting a table and outputting the image. 3. The original determination signal is output without adding a new tracking pattern when the original determination signal expanded from the image storage section indicates a copy original. The image processing device described.