Image processing device, image processing method, and storage medium
AssigneeCanon Kabushiki Kaisha
InventorsRyosuke Otani, Hisashi Ishikawa
Life of this patent
Estimating the term…
Abstract
A quantized value for a pixel of interest in an input image is derived by using a predetermined threshold value matrix. Then, based on a pixel value group in a predetermined reference area including the pixel of interest in the input image and a threshold value group corresponding thereto, directionality of correction is determined. Further, based on the pixel value group and the threshold value group, whether or not the pixel of interest satisfies a predetermined condition for changing the quantized value is determined. Then, based on both the determination results, the quantized value is corrected.
Claims16
An image processing device that generates a halftone image by performing quantization processing for an input image, the device comprising:
- a processor;
- and
- a memory, including instructions stored thereon, which, when executed by the processor, cause the image processing device to:
- derive a quantized value corresponding to a pixel of interest in the input image by using a threshold value matrix;
- perform a first determination relating to correction for the quantized value based on a pixel value group in a reference area including the pixel of interest in the input image and a threshold value group corresponding to the pixel value group in the threshold value matrix;
- perform a second determination relating to whether or not the pixel of interest satisfies a predetermined condition for changing the quantized value based on the pixel value group and the threshold value group;
- and
- correct the quantized value based on determination results of the first determination and determination results of the second determination.
An image processing method of generating a halftone image by performing quantization processing for an input image, the method comprising:
- deriving a quantized value corresponding to a pixel of interest in the input image by using a threshold value matrix;
- performing a first determination relating to correction for the quantized value based on a pixel value group in a reference area including the pixel of interest in the input image and a threshold value group corresponding to the pixel value group in the threshold value matrix;
- performing a second determination relating to whether or not the pixel of interest satisfies a predetermined condition for changing the quantized value based on the pixel value group and the threshold value group;
- and
- correcting the quantized value based on determination results at the first determination and determination results at the second determination.
A non-transitory computer readable storage medium storing a program for causing a computer to perform an image processing method of generating a halftone image by performing quantization processing for an input image, the method comprising:
- deriving a quantized value corresponding to a pixel of interest in the input image by using a threshold value matrix;
- performing a first determination relating to correction for the quantized value based on a pixel value group in a reference area including the pixel of interest in the input image and a threshold value group corresponding to the pixel value group in the threshold value matrix;
- performing a second determination relating to whether or not the pixel of interest satisfies a predetermined condition for changing the quantized value based on the pixel value group and the threshold value group;
- and
- correcting the quantized value based on determination results at the first determination and determination results at the second determination.
Dependencies are inferred from the claim text.