JPH08102856A - Picture processor - Google Patents

Abstract

PURPOSE: To obtain a picture processor whereby the calibration of a device is executed in an appropriate time. CONSTITUTION: Data for a γ correction table which is calculated by a calibration arithmetic part 105 is transmitted to a stacked memory 107. The stacked memory 107 combines transmitted data for the γ correction table with a calculated date to store it. A calibration arithmetic equipment 105 predicts the proper period fo a next calibration based on data stored in the stacked memory 107 and indicates an output urging the execution of the calibration to an operator in the above period.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing device, and more particularly, to an image processing device which performs calibration in order to obtain stable color output.

[0002]

2. Description of the Related Art In an image processing apparatus such as a copying machine, the output image may be different even when copying from the same document due to changes in the internal mechanism of the apparatus over time. Especially, in an image processing device that handles color images, this difference in output images is very noticeable.
Had been a problem.

In order to solve this problem and obtain a stable color output, an image processing apparatus that performs calibration has been known. For example, in a calibration operation in a color digital copying machine (hereinafter referred to as a copying machine), when an operator instructs the calibration, the copying machine first uses the color patch image data built in the main body to A specific color patch is recorded on recording paper and output.

The operator places the color patch output from the copying machine on the document table of the copying machine. Next, the operator
Press the scan button according to the instructions of the copier. The copier reads the image of the color patch placed on the platen.
The read image data is compared with the image data that should be originally output, that is, the image data for the color patch built in the main body, the difference is calculated, and the difference is corrected manually or automatically. By this series of operations, a stable color image is output.

To execute the calibration in such a color digital copying machine, the device manager periodically
Alternatively, the operation was performed when the operator felt that the output image was unpleasant.

[0006]

However, the above-mentioned conventional apparatus has the following problems. When the device administrator regularly calibrates, the device becomes unstable when the above environment changes during the period between calibration executions, and the device becomes unstable until the next calibration execution. It may not be possible to output a normal color image.

Further, when the apparatus is stable, it is not necessary to calibrate, so that periodical calibration may be useless. further,
When the operator performs the calibration, the operator actually sees the output image and executes the calibration only when he feels that the output image is abnormal. Therefore, the level at which abnormality is felt differs depending on the operator, and the timing of calibration execution changes, so it may not always be possible to obtain a normal output image.

[0008]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and performs γ correction on an input image signal based on a predetermined correction coefficient, and after the γ correction, An image processing apparatus that forms an image based on an image signal, outputs a test image based on a reference image signal, reads the test image, and compares the read image signal with the reference image signal to perform the correction. In the image processing device for calculating the coefficient, a storage unit for storing the correction coefficient and the time when the correction coefficient is calculated in combination,
The calculation unit calculates a correction coefficient based on the stored content of the storage unit, and calculates the correction coefficient based on the tendency of the correction coefficient calculated by the calculation unit. We adopted a configuration that predicts when to do it and issues a warning at the predicted time.

Further, the correction coefficient at the time when the predicted correction coefficient is calculated is predicted, and when the difference between the predicted correction coefficient and the calculated correction coefficient is larger than a predetermined value, the correction coefficient is calculated again. We adopted a configuration that issues a warning. In addition, if there is a tendency that the interval between the time when the predicted correction coefficient is calculated and the time when the next correction coefficient is calculated tends to be short, we have adopted a configuration that issues a warning.

[0010]

Since the present invention employs the above configuration, it predicts the time when the correction coefficient is calculated based on the change over time in the past, and gives a warning to the operator to perform the operation at the predicted time. be able to. Also, when the calculated correction coefficient is significantly different from the predicted correction coefficient, a warning is issued, so
The operator's erroneous operation can be dealt with.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below with reference to the accompanying drawings. FIG. 1 is an overall configuration diagram of a digital copying machine which is an embodiment adopting the present invention. The image input unit 101 is a scanner that optically scans and reads a document image, and outputs the read image data to the shading correction / masking processing unit 102 of the image processing unit.

Shading correction / masking processing unit 1
Reference numeral 02 applies shading correction and masking processing to the image data input from the image input unit 101, and then outputs the image data to the γ correction unit 103. The γ correction unit 103
By referring to the correction table 106, γ correction is performed on the input data, and the processed image data is output to the image output unit 1.
Output to 04.

The γ correction table 106 is a table in which input data and output data output when predetermined input data is input are associated with each other. The data of the γ correction table 106 is rewritable, and the output value with respect to the input can be changed by rewriting.

The image output unit 104 forms and outputs an output image on a recording sheet according to the data output from the image processing unit.

Calibration calculator 1 of the image processing unit
05 is a calibration operation described later,
Image data for color patch and image input unit 10
1 is a unit that compares and calculates the image data of the color patch read and calculates the data for the γ correction table.

The data calculated by the calibration calculator 105 is sent to the above-mentioned γ correction table. The calculated data is also sent to and stored in the stack memory 107.

Next, the calibration operation of the digital copying machine of this embodiment will be described. For some time after the device is installed, calibration is performed periodically with a timer. In this case, the device manager may periodically perform the calibration.

In the calibration, first, a color patch is output from the image output unit 104 based on the color patch data stored in a color patch memory (not shown). The operator inputs the output color patch to the image input unit 1
Read from 01. The image data read by the image input unit 101 is the shading correction / masking processing unit 1.
It is input to the calibration calculator 105 via 02.

The calibration calculator 105 stores the color patch data stored in the color patch memory and
The read color patch data is compared, and the difference is used to calculate the γ correction table data for outputting a color patch of the same color as the color patch data stored in the color patch memory.

The calculated data is the γ correction table 10
3 and the stack memory 107. γ correction unit 1
03 performs γ correction based on the data for the γ correction table calculated by the calibration calculator 105. The stack memory 107 stores the sent γ correction table data in combination with the date of calibration.

After performing the above-described periodical calibration several times, the calibration calculator 105 determines the combination of the data for the γ correction table for several times stored in the stack memory 107 and the date of calibration. Based on this, the tendency of changes in output characteristics over time is calculated. Based on the calculated tendency, the time when the fluctuation value of the predetermined γ correction table data is exceeded, that is, the time suitable for performing the next calibration is calculated, and when the calculated time comes, the operator is calibrated. Is displayed to prompt execution of.

This operation will be described with reference to the flowchart of FIG. In step S201, the current date is acquired. It is determined whether the acquired date is the calculated calibration execution date (S202), and if it is the calibration execution date, a warning prompting the calibration to be executed in step S203, for example, "calibration". Please perform. ”Is displayed, and if not, the processing ends.

In the apparatus of this embodiment, after performing calibration several times periodically, based on the change over time in the past,
An appropriate time to perform the calibration is calculated, and at that time, a display prompting the execution of the calibration is displayed, so that proper calibration can be performed without waste.

In the apparatus of the above-described embodiment, if the tendency of the change in the output characteristics with time is in the diverging direction, the correction by the calibration becomes impossible, and there is a possibility that the correct color cannot be output. In this case, the operator can be warned.

In the flowchart of FIG. 3, the tendency of the change in the output characteristic is calculated in step S303. It is determined whether the calculated tendency of change is in the direction of divergence (S30
4) If it is in the direction of divergence, a warning is displayed, for example, "If this is the case, color adjustment may not be possible. Please call a service person." If not, the process ends.

Further, when the calibration interval stored in the stack memory 107 tends to be short, a similar warning is displayed. In this example,
The abnormality of the device can be detected and dealt with early.

In the above-described series of calibration operations, when the operator sets the color patch on the image input section, the position may shift. In this case, the γ correction table data calculated by calibration is
It will be very different from the predicted data. This difference in data can be used to prevent operator mistakes in setting.

In the flowchart of FIG. 4, the difference between the data predicted in step S401 and the data calculated by calibration is calculated. It is determined whether or not the calculated difference is within a predetermined range (S402), and if it is not within the predetermined range, display is performed so that calibration is performed again in step S403. If it is within the predetermined range, the process ends.

With this configuration, when an operator makes a mistake in setting a color patch, a warning is issued to prompt the user to perform calibration again, so that a malfunction due to a mistake in setting can be prevented.

[0030]

As described above, according to the present invention, the γ is calculated for the input image signal based on the predetermined correction coefficient.
An image processing apparatus which performs correction and forms an image based on the γ-corrected image signal, which outputs a test image based on a reference image signal, reads the test image, and reads the read image signal and the reference image signal. In an image processing apparatus that calculates the correction coefficient by comparing image signals, a storage unit that stores the correction coefficient and the time when the correction coefficient is calculated in combination, and the correction coefficient elapsed time based on the storage content of the storage unit. Has a calculating means for calculating the tendency of the dynamic change, predicts the time when the correction coefficient is calculated based on the tendency of the change of the correction coefficient calculated by the calculating means with time, and issues a warning at the predicted time. Since the configuration is adopted,
This has the effect of prompting the operator to perform calibration at an appropriate time.

Further, since the correction coefficient at the time when the predicted correction coefficient is calculated is predicted, and the difference between the predicted correction coefficient and the calculated correction coefficient is larger than a predetermined value, a warning is issued. ， There is an effect that can respond to the malfunction of the operator. In addition, if there is a tendency that the interval between the time when the predicted correction coefficient is calculated and the time when the next correction coefficient is calculated tends to be short, a configuration that issues a warning is adopted, so that an early response to a device abnormality is possible. There is a possible effect.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of an apparatus according to an embodiment of the present invention.

FIG. 2 is a flowchart illustrating an operation procedure.

FIG. 3 is a flowchart illustrating an operation procedure.

FIG. 4 is a flowchart illustrating an operation procedure.

[Explanation of symbols]

 Reference Signs List 101 image input unit 102 shading correction / masking processing unit 103 γ correction unit 104 image output unit 105 calibration calculation unit 106 γ correction table 107 stack memory

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location // G06F 11/30 305 B 7313-5B

Claims (3)

[Claims] 1. An image processing apparatus for performing γ correction on an input image signal based on a predetermined correction coefficient, and forming an image based on the image signal after the γ correction, the image processing apparatus based on a reference image signal. In an image processing apparatus that outputs a test image, reads the test image, and calculates the correction coefficient by comparing the read image signal with the reference image signal, the correction coefficient and the time when the correction coefficient is calculated are combined. And a storage unit for storing and a calculation unit for calculating the tendency of the change of the correction coefficient with time based on the stored content of the storage unit. Based on the tendency of the change of the correction coefficient with time calculated by the calculation unit, An image processing apparatus, which predicts a time when the correction coefficient is calculated and issues a warning at the predicted time. 2. The image processing apparatus according to claim 1, wherein the correction coefficient at the time of calculating the predicted correction coefficient is predicted, and the difference between the predicted correction coefficient and the calculated correction coefficient is greater than a predetermined value. An image processing device characterized by issuing a warning when large. 3. The image processing apparatus according to claim 1, wherein a warning is issued when the interval between the time when the predicted correction coefficient is calculated and the time when the next correction coefficient is calculated tends to be short. A characteristic image processing device.