Image processing method, image processing apparatus and recording medium
AssigneeSharp Kabushiki Kaisha
InventorTerumitsu KATOUGI
Life of this patent
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Abstract
When generating output image data represented by a reduced number of gray levels from gray level image data, an image processing apparatus subtracts a pixel value of a selected pixel from a pixel value of adjacent pixel, amplifies the reduced value obtained by the subtraction, adds the amplified value to a numerical value in a numerical matrix, and finds a pixel value in the output image data represented by a reduced number of gray levels of pixel values, based on a value obtained by further adding a value obtained by adding the amplified value to the numerical value in the numerical matrix to a predetermined value.
Claims14
An image processing method for performing image processing for reducing the number of gray levels of image data, comprising the steps of:
- storing a numerical matrix composed of predetermined numerical values which are arranged in a matrix form and correspond to pixels, respectively, which are arranged in an image represented by the image data;
- selecting successively each of the pixels in the image represented by the image data;
- calculating a difference between a pixel value of a selected pixel and a pixel value of a pixel adjacent to the selected pixel;
- converting the calculated difference by a predetermined conversion method;
- adding the converted value to a numerical value in the numerical matrix corresponding to the selected pixel;
- and
- processing the pixel value of the selected pixel based on a value obtained by the addition to find a pixel value represented by a reduced number of gray levels for the pixel value.
An image processing apparatus for generating output image data represented by a reduced number of gray levels of image data, comprising:
- a storing section for storing a numerical matrix composed of predetermined numerical values which are arranged in a matrix form and correspond to pixels, respectively, which are arranged in an image represented by the image data;
- a calculating section for selecting successively each of the pixels in the image represented by the image data and calculating a difference between a pixel value of a selected pixel and a pixel value of a pixel adjacent to the selected pixel;
- a converting section for converting the difference calculated by the calculating section by a predetermined conversion method;
- an adding section for adding a converted value given by the converting section to a numerical value in the numerical matrix corresponding to the selected pixel;
- and
- a processing section for processing the pixel value of the selected pixel based on a value obtained by the addition to find a pixel value in output image data represented by a reduced number of gray levels of the pixel values.
An image processing apparatus for generating output image data represented by a reduced number of gray levels of image data, comprising:
- means for storing a numerical matrix composed of predetermined numerical values which are arranged in a matrix form and correspond to pixels, respectively, which are arranged in an image represented by the image data;
- means for selecting successively each of the pixels in the image represented by the image data;
- calculating means for calculating a difference between a pixel value of a pixel selected by said means and a pixel value of a pixel adjacent to the selected pixel;
- converting means for converting the difference calculated by the calculating means by a predetermined conversion method;
- means for adding a converted value given by the converting means to a numerical value in the numerical matrix corresponding to the selected pixel;
- and
- processing means for processing the pixel value of the selected pixel based on a value obtained by the addition to find a pixel value in output image data represented by a reduced number of gray levels of the pixel values.
A recording medium readable by a computer and storing a computer program for causing a computer, which stores a numerical matrix composed of predetermined numerical values arranged in a matrix form and correspond to pixels, respectively, which are arranged in an image represented by image data, to generate output image data represented by a reduced number of gray levels of the image data, the computer program performing a method comprising:
- a step of causing the computer to select successively each of the pixels in the image represented by the image data;
- a step of causing the computer to calculate a difference between a pixel value of a selected pixel and a pixel value of a pixel adjacent to the selected pixel;
- a step of causing the computer to convert the calculated difference by a predetermined conversion method;
- a step of causing the computer to add the converted value to a numerical value in the numerical matrix corresponding to the selected pixel;
- and
- a step of causing the computer to process the pixel value of the selected pixel based on a value obtained by the addition to find a pixel value in output image data represented by a reduced number of gray levels of the pixel values.
Dependencies are inferred from the claim text.