JP2003060914A - Imaging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an imaging device that can easily change a gamma line. SOLUTION: A reference point of the gamma line desirably to be changed is set and adjustment points A, B with the reference point inbetween are set. Then a moving destination of the reference point is decided, and a change amount = (an output value at a reference point after the change) - (an output value at a reference point before the change) is calculated. Then a PA = (the change amount of the reference point) ÷ (an input value at the reference point, after the change) - (an input value at the adjustment point A)} and PB = (the change amount of the reference point) ÷ (an input value at the reference point, after the change) - (an input value at the adjustment pint B)} are obtained as parameter values. They respectively represent the gradient of a straight line, passing through the reference point and the adjustment point A and the gradient of a straight line, passing through the reference point and the adjustment point B. Then the absolute value of a distance dn, from each adjustment point to the reference point, = (input value at the reference point) -(input value at each adjustment point) is obtained. Then a change amount An at the adjustment point A, after the change between the reference point after the change and the adjustment point A is becomes An=dn×PA, and a change amount Bn at the adjustment point B after the change between the reference point after the change and the adjustment point B is expressed as Bn=dn×PB. Adding An, Bn to each adjustment point enables obtaining the adjustment point, after the change.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus using a gamma line formed on the basis of adjustment points for adjusting an output image of a printer or the like, and more particularly to a color printer or the like in which the need for the gamma line is high. The present invention relates to an image forming apparatus suitable for use.

[0002]

2. Description of the Related Art Conventionally, a gamma line (an image correction curve having a correction characteristic such as gamma correction) is used to adjust an output image of a color printer, and this gamma line is formed by using a plurality of adjustment points. . When changing a gamma line, each adjustment point was changed and a new gamma line was formed using the changed adjustment point.

[0003]

However, when the number of adjustment points is large, in order to change the data of each adjustment point, it has to be manually changed one by one, which requires a great deal of work.

The present invention has been made to solve the above problems, and it is an object of the present invention to simplify the work of changing adjustment points other than the above one by determining one adjustment point and a parameter value. .

[0005]

To achieve the above object, in an image forming apparatus according to the present invention, a plurality of adjustment points forming an image correction curve for adjusting an output image with respect to an input image are provided. One of them is used as the reference point, the amount of change of this reference point is determined, the slope of the straight line passing through the changed reference point and the predetermined adjustment point is calculated as a parameter value, and the parameter value is used A calculation means for calculating the change amount of each adjustment point is provided.

[0006]

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 showing an image forming apparatus according to an embodiment of the present invention. In FIG. 1, the present apparatus includes a printer 8, an input device 3 operated by an operator 2, and a data processing device 7 for processing data of the printer 8.
And a display device 1 for displaying to the operator 2. The printer 8 includes a storage device 4 that stores adjustment point data, an arithmetic processing device 5 that calculates gamma line data using the adjustment point data, and a storage device 6 that stores the calculated gamma line data. Have.

Next, the operation will be described with reference to the characteristic diagrams of FIGS. 4 and 5 and the flowchart of FIG. The arithmetic processing unit 5 calculates the gamma line data using the data of the plurality of adjustment points stored in the storage unit 4, and the calculated gamma line data is stored in the storage unit 6.
The data processing device 7 reads the gamma line data from the storage device 6 and also reads each adjustment point data from the storage device 4, and causes the display device 1 to display the gamma lines and the adjustment points in a graph.

FIG. 2 shows the displayed gamma lines and adjustment points. The horizontal axis shows the input image data and the vertical axis shows the output image data. Each adjustment point is indicated by □, and the line connecting each adjustment point is a gamma line.

The operator 2 looks at the graph of FIG. 2 to determine the point to be adjusted, and the input device 3 sets one point to be adjusted as a reference point as shown in FIG. 3, and then sandwiches the reference point. The adjustment point A and the adjustment point B are set (steps S1 and S2 in FIG. 6, hereinafter, step omitted). Next, operator 2
Inputs the destination of the reference point using the input device 3 (S
3).

Next, as shown in FIG. 4, after the change amount of each adjustment point is set to 0, the data processing device 7 changes the reference point = (changed reference point output value) − (before change) The output value of the reference point) is calculated (S4). In the present embodiment, the adjusted adjustment points A1, A2, ..., B1, B2, ... Of the adjustment points other than the adjustment points A and B are obtained based on the changed reference points.

For this purpose, first, the parameter value PA = (amount of change of reference point) / {(input value of reference point after change)-(input value of adjustment point A)} parameter value PB = (amount of change of reference point) ) ÷ {(input value of reference point after change)-(input value of adjustment point B)}. This parameter value represents the slope of a straight line passing through the changed reference point and each of the adjustment points A and B. Next, according to the absolute value of dn = {(input value of reference point)-(input value of adjustment point)}, the distance dn (n = 1
, 2, 3, ──).

The change amount An of each post-change adjustment point between the post-change reference point and the adjustment point A is: An = dn × PA A change of each post-change adjustment point between the post-change reference point and the adjustment point B The quantity Bn is Bn = dn * PB (S5). By adding An and Bn to each adjustment point (S6), a new adjustment point (adjustment point after change) can be obtained as shown in FIG.

FIG. 7 is a flow chart showing the procedure for changing the gamma line. After initialization of the printer (S11), the calculated new adjustment point is sent to the storage device 4, the gamma line is formed by the arithmetic processing device 5 and sent to the storage device 6.
It is displayed on the display device 1 by the data processing device 7 (S1
2, S13). This is confirmed by the operator 2, and it is determined whether or not the change is necessary (S14). If the change is necessary, the above-described processing such as setting the reference value and changing the adjustment point is performed again to calculate a new gamma line. (S15-S1
8). If the change is not necessary, the change work is finished.

As described above, according to the present embodiment, one of a plurality of adjustment points necessary for forming a gamma line for adjusting an output image is used as a reference point to determine the amount of change. After setting the change amount of each adjustment point to 0, the slope of the straight line passing through the changed reference point and the predetermined adjustment point is calculated as a parameter value, and using this parameter value, each adjustment point other than the reference point is changed. Since the gamma line is changed by determining the amount, it is possible to automatically change each adjustment point other than the reference point. In addition, the influence range of the adjustment point to be changed can be easily understood, and the adjustment can be facilitated.

Although a plurality of parameter values and the number of adjustment points to be changed are set, if the change amounts of the adjustment points overlap, the smaller one is determined as the change amount of the adjustment points, so that I can clarify the points. Further, the gamma line has a plurality of gradations, and there are three or more adjustment points.

[0016]

According to the invention described in claim 1, it is possible to automatically change the adjustment point other than the reference point by using the change of the reference point and the parameter value, and the conventional manual movement of the adjustment point. The work can be reduced. According to the second aspect of the present invention, the influence range of the adjustment point that is automatically changed by the method of determining the parameter value by the adjustment point can be easily understood and adjusted. According to the third aspect of the invention, it is possible to solve the problem that occurs when determining the magnitude of the change amount of a plurality of points, and clarify the changed point. According to the invention described in claim 4, it is possible to guarantee that there are a plurality of adjustment points and the adjustment points can be changed.

[Brief description of drawings]

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

FIG. 2 is a characteristic diagram showing a display example of gamma lines and adjustment points.

FIG. 3 is a characteristic diagram showing a setting example of reference points and adjustment points A and B.

FIG. 4 is a characteristic diagram showing the determination of the inclination and the amount of change at each adjustment point.

FIG. 5 is a characteristic diagram showing gamma lines before and after adding a change amount to each adjustment point.

FIG. 6 is a flowchart showing a procedure for determining an inclination and a change amount.

FIG. 7 is a flowchart showing a procedure of a method for changing an adjustment point.

[Explanation of symbols]

1 Display device 2 operators 3 input devices 4 storage devices 5 Processor 6 storage devices 7 Data processing device 8 printers

Claims (4)

[Claims] 1. A reference point is defined as one of a plurality of adjustment points forming an image correction curve for adjusting an output image with respect to an input image, and a change amount of the reference point is determined. Image formation characterized by including calculation means for calculating a slope of a straight line passing through the point and a predetermined adjustment point as a parameter value, and using the parameter value to calculate a change amount of each adjustment point other than the reference point apparatus. 2. The image forming apparatus according to claim 1, wherein each of the adjustment points is set so that a change amount is 0, and the parameter value is calculated. 3. The parameter value or the change amount is 0.
3. The image forming apparatus according to claim 2, wherein a plurality of adjustment points can be set, and when the adjustment amounts of the adjustment points overlap, the smaller one is determined as the adjustment amount of the adjustment point. 4. The image correction curve is a gamma line having a plurality of gradations, and there are a plurality of adjustment points of three or more adjustment points. Image forming apparatus.