Image forming apparatus and image forming method therefor

Patent metadata

Field	Value
Publication number	US-9247105-B2
Application number	US-201113291813-A
Country	US
Kind code	B2
Filing date	Nov 8, 2011
Priority date	Dec 10, 2010
Publication date	Jan 26, 2016
Grant date	Jan 26, 2016

Abstract

An image forming apparatus detects an edge in image data and performs density correction so as to reduce the density of the detected edge. The apparatus then performs screen processing on the image data including the edge that has undergone the density correction, and performs smoothing processing on the edge in screen data obtained through the screen processing.

First claim

What is claimed is:

1. An image forming apparatus comprising:
a determination unit configured to determine whether or not to perform smoothing processing to a pixel of image data;
a correction unit configured to reduce a value of a pixel to which the determination unit determines the smoothing processing is to be performed;
a screen processing unit configured to generate screen data by performing screen processing to the pixel corrected by the correction unit; and
a smoothing processing unit configured to perform the smoothing processing to the pixel to which the determination unit determines the smoothing processing is to be performed by comparing a value of the generated screen data and a value generated from the pixel value after correction by the correction unit, and outputting data having a greater value.

2. The apparatus according to claim 1 , further comprising a gamma correction unit configured to perform gamma correction for the pixel corrected by the correction unit.

3. The apparatus according to claim 1 , wherein the smoothing processing unit performs the second smoothing processing by comparing a value of the generated screen data and a value generated from the value of the pixel after correction by the correction unit, and outputting data having a greater value.

4. The apparatus according to claim 1 , wherein the correction unit reduces the value of the pixel using a one-dimensional look-up table.

5. An image forming method comprising:
a determination step of determining whether or not to perform smoothing processing to a pixel of image data;
a correction step of reducing a value of a pixel to which the determination step determines the smoothing processing is to be performed;
a screen processing step of generating screen data by performing screen processing to the pixel corrected in the correction step; and
a smoothing processing step of performing the smoothing processing to the pixel to which the determination step determines the smoothing processing is to be performed by comparing a value of the generated screen data and a value generated from the pixel value after correction in the correction step, and outputting data having a greater value.

6. A non-transitory computer-readable recording medium storing a program for causing a computer to execute an image forming method, the image forming method comprising:
a determination step of determining whether or not to perform smoothing processing to a pixel of image data;
a correction step of reducing a value of a pixel to which the determination step determines the smoothing processing is to be performed;
a screen processing step of generating screen data by performing screen processing to the pixel corrected in the correction step; and
a smoothing processing step of performing the smoothing processing to the pixel to which the determination step determines the smoothing processing is to be performed by comparing a value of the generated screen data and a value generated from the pixel value after correction in the correction step, and outputting data having a greater value.

7. An image forming apparatus comprising:
a first determination unit configured to determine whether or not to perform a first smoothing processing to each pixel of image data;
a second determination unit configured to determine whether or not to perform a second smoothing processing to a pixel to which the first determination unit determines the first smoothing processing is not to be performed;
a correction unit configured to reduce a value of a pixel to which the second determination unit determines the second smoothing processing is to be performed;
a screen processing unit configured to generate screen data by performing screen processing to the pixel corrected by the correction unit;
a smoothing processing unit configured to perform the second smoothing processing to the pixel to which the second determination unit determines the second smoothing processing is to be performed, based on the generated screen data and a value of the pixel after correction by the correction unit;
a control unit configured to control so as not to perform processing by the correction unit and the screen processing unit to a pixel to which the first determination unit determines the first smoothing processing is to be performed.

8. An image forming method comprising:
a first determination step of determining whether or not to perform a first smoothing processing to each pixel of image data;
a second determination step of determining whether or not to perform a second smoothing processing to a pixel to which the first determination step determines the first smoothing processing is not to be performed;
a correction step of reducing a value of a pixel to which the second determination step determines the second smoothing processing is to be performed;
a screen processing step of generating screen data by performing screen processing to the pixel corrected by the correction step;
a smoothing processing step of performing the second smoothing processing to the pixel to which the second determination step determines the second smoothing processing is to be performed, based on the generated screen data and a value of the pixel after correction by the correction step;
a control step of controlling so as not to perform processing by the correction step and the screen processing step to a pixel to which the first determination step determines the first smoothing processing is to be performed.

Assignees

• Kashibuchi Yoichi
• Canon Kk

Inventors

• Kashibuchi Yoichi

Classifications

• H04N1/4092 Primary

  Edge or detail enhancement · CPC title