JPH03219781A - Picture processing unit - Google Patents

Abstract

PURPOSE:To attain optimum picture processing by applying picture processing to plural colors of color picture information subjected to multi-value processing and outputting plural colors of color picture information subjected to binarizing processing with the density conservation type binarizing method. CONSTITUTION:A binary color picture data binarized by the binarizing method not the density conservation type such as the organizing dither method or the like is stored in a binary color picture database 1. A multi-value arithmetic section 2 receives a binary color picture data from the database 1 to apply multi-value processing for the binary color picture for a masking arithmetic section 3. The masking arithmetic section 3 applies various picture processings to the color picture data subjected to multi-value processing by the multi-value arithmetic section 2. An error spread method arithmetic section 4 uses an error spread method one of known density conservation type binarizing methods to spread an error caused in the binarization of a noted picture element to surrounding picture elements to conserve the density as the binarizing processing. Then a color printer is used for an output section 5 in this embodiment.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an image processing device, and particularly relates to an image processing device that performs image processing on multivalued image information and binarizes the image information. be.

[Prior Art] Conventionally, color image databases used in image processing apparatuses and the like usually store color image data, and the data is multivalued image data. In other words, each pixel of a multivalued image is represented by, for example, R, G, and B data each using 8 bits. When outputting multivalued image data to a color printer, it is configured to perform image processing such as γ correction and masking, and output the corrected image to be optimal for the characteristics of the color printer.

[Problems to be Solved by the Invention] However, in the above conventional example, since the database is multivalued image data, the amount of data becomes large, and problems such as memory capacity, processing speed, etc. arise when constructing an image database. Point-to-binary color image databases have been attracting attention. This binary color image is a multivalued color image converted into a binary image using some kind of binarization method. For example, each pixel has 1 bit each for R, G, and B.
That is, it is expressed as "0" or "1".

However, when outputting binary color image data to a color printer, even if image processing such as γ correction and color correction is performed using conventional methods to create an image that is optimal for the characteristics of the color printer, “ In the binary data of “0” and “1”,
There is a drawback that the result of multiplication by the calculation count becomes "O゛°" or a fixed value, making it impossible to perform optimal processing.

Particularly when the output color printer is a binary color printer, it is difficult to directly modify the binary color image data.

The present invention was made to solve the above problems, and
It is an object of the present invention to provide an image processing device that can perform optimal image processing by converting input binary image information into multiple values.

[Means and operations for solving the problems] In order to achieve the above object, an image processing apparatus of the present invention has the following configuration. That is, image processing is performed on multivalued image information, and 2
An image processing device that performs digitization, comprising an input means for inputting binary color image information for a plurality of colors, and a multi-value conversion means for performing multi-value conversion on each of the binary color image information input by the input means. , performs image processing on color image information for multiple colors multi-valued by the multi-value conversion means, and outputs color image information for multiple colors binarized using a density-preserving binarization method; Features.

[Embodiment] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

<Description of Configuration (FIG. 1)> FIG. 1 is a schematic block diagram showing the configuration of an image processing apparatus in this embodiment. In the figure, l is a binary color image database, which stores binary color image data that has been binarized using a non-density-preserving binarization method such as a systematic dither method. In this embodiment, each pixel of the binary color image has one bit each of R, G, and B, that is, 'O°
.

Or “expressed in 1°°”.

Reference numeral 2 denotes a multi-value calculation unit in this embodiment, which inputs binary color image data from the above-mentioned binary color image database 1 and converts the binary color image into multiple values for the masking calculation unit 3, which will be described later. This is an arithmetic unit that performs value conversion. 3 is a masking calculation section, which is a calculation section that performs various image processing on the color image data multi-valued by the multi-value calculation section 2; Reference numeral 4 denotes an error diffusion method calculation unit, and in this embodiment, an error generated during binarization of the pixel of interest is transferred to surrounding pixels using the error diffusion method, which is one of the known density-preserving binarization methods. This is an arithmetic unit that performs a binarization process that allows diffusion and density preservation. Further, 5 is an output unit, which in this embodiment is a color printer.

Note that each of the calculation units 2 to 4 described above is controlled by a control unit (not shown). The control unit uses a CPU that controls the entire device, a ROM that stores processing procedures (programs) executed by the CPU, and a RAM that includes a work area and various tables that are used when executing the processing procedures in the ROM. It is configured.

Explanation of Processing Procedures (FIGS. 2 and 3) Next, the multi-value processing in this embodiment will be explained below according to the flowchart shown in FIG.

First, in step Sl, desired binary color image data of R, G,
Input each pixel of B (1 bit each). and,
The process advances to the next step S2, and the bit values of each R, G, and B pixel are multiplied by "255". In other words, one bit of each pixel of R, G, and B becomes 8 bits, and the bit value becomes "0" or "255".

Next, when the multi-value processing is completed for the desired binary color image data, the process proceeds to step S3, where the multi-value image data R, G, and B are output to the masking calculation section 3, and the process ends. .

With the above processing, the multivalue processing of the binary color image data in this embodiment is completed, and the masking calculation unit 3 performs image processing that is optimal for the characteristics of the color printer 5.

FIG. 3 is a flowchart showing the processing in the masking calculation unit 3.

First, in step SIO, each 8-bit R, G, and B pixel output from the multivalue calculation unit 2 is converted into C (cyan), 9M (magenta), and Y (yellow) corresponding to the ink characteristics of the color printer 5. Logarithmically transform. In this example, R
, G, and B are each 8 bits, so it is converted into C, M, and Y by subtracting the values of R, G, and B from "255". Next, the process proceeds to step Sll, and the converted C, M, and Y are multiplied by masking coefficients as shown in FIG. 4, for example.

The C, M, and Y data thus processed are then binarized by the error diffusion calculation unit 4, and a permanent visible image is formed by the color printer 5.

As explained above, according to this embodiment, the binary image data obtained by converting a multi-value original image into a binary image using a non-density-preserving binarization method such as a systematic dither method is multi-valued. By performing image processing and binarizing using a density-preserving binarization method, an image that has undergone appropriate image processing can be obtained.

In this embodiment, binary data is output to the color printer 5, but the color printer 5 is not used (for example, a CRT
An output device such as a display or a liquid crystal display may be used. Also, instead of outputting to an external output device,
The value may be stored in the color image database 1.

In addition, in the multivalue calculation unit 2 described above, as a multivalue conversion method,
Although the R, G, and B values of each pixel are multiplied by 255, it may be configured to not only be multiplied by 255° but also processed as an average value including surrounding pixels. and,
It is not necessarily limited to "255" times, but may be other numerical values such as "127" times, for example. Further, depending on the masking method, a plurality of types of multi-value encoding methods may be combined.

In this example, binarization is performed using the error diffusion method, but
For example, other concentration-preserving binarization methods such as the minimum average error method may also be used. Furthermore, even if the systematic dither method is a binarization method that is not density-preserving in principle, it may be modified to preserve the density by, for example, diffusing errors.

Further, in this embodiment, a binary color image is obtained from a binary color image database, but binary color image data may be input from an image input device such as a color scanner or a video camera.

Further, in this embodiment, a binary color image is obtained from a binary color image database, but a modem or the like may be connected to receive binary color image data through a telephone line or the like.

In this embodiment, a binary color image is input from a binary color image database, but binary color image data received by a TV receiver may also be used.

[Effects of the Invention] As described above, according to the present invention, optimal image processing can be performed by converting input binary image information into multivalued information.

[Brief explanation of drawings]

FIG. 1 is a schematic block diagram showing the configuration of the image processing device in this embodiment, FIGS. 2 and 3 are flowcharts showing the processing procedure in this embodiment, and FIG. 4 is a diagram for explaining the masking pattern. be. In the figure, 1...binary color image database, 2...
Multi-value calculation section, 3... Masking calculation section, 4... Error diffusion method calculation section, 5... Color printer. 7: Figure 1/Mamoru 3' Figure 32 Figure 4

Claims (1)

[Claims] Image processing is performed on multivalued image information, and two parts of the image information are
An image processing device that performs digitization, comprising an input means for inputting binary color image information for a plurality of colors, and a multi-value conversion means for performing multi-value conversion on each of the binary color image information input by the input means. , performs image processing on color image information for multiple colors multivalued by the multivalue conversion means,
An image processing device that outputs color image information for a plurality of colors that has been binarized using a density-preserving binarization method.