IMAGE DATA CONVERSION DEVICE, IMAGE DATA CONVERSION METHOD, IMAGE DATA CONVERSION PROGRAM, POS TERMINAL DEVICE, AND SERVER
First Claim
1. An image data conversion device that represents color image data in gray scale to convert the color image data to black-and-white image data, the image data conversion device comprising:
- gray scale operation unit configured to represent the color image data in gray scale;
histogram creation unit configured to create a histogram of brightness values for gray-scaled image data;
determination unit configured to, based on created histogram, determine which image pattern of image patterns of bright image, a dark image, a highly contrasted image whose contrast that is a difference in a brightness between a bright portion and a dark portion is significantly large, and an image which is not included in any of the bright image, the dark image, and the highly contrasted image the gray-scaled image data is classified into; and
image data conversion unit configured to, in accordance with which image of the bright image, the dark image, the highly contrasted image, and the image not included any of the above a determined image pattern is classified into, set a brightness value range on which gamma correction is performed for the gray-scaled image data, set a brightness value range on which correction for fixing a brightness value to at least one of a minimum value and a maximum value of gray scale is performed for the gray-scaled image data, and perform image data conversion including the gamma correction and correction for fixing a brightness value to at least one of the minimum value and the maximum value of the gray scale for the gray-scaled image data,wherein the bright image is an image in which a peak having the highest brightness value is present above a second threshold greater than a first threshold of a brightness value in the histogram and the peak is not present below the first threshold,wherein the dark image is an image in which the peak is present below the first threshold, the total number of pixels above the first threshold is greater than or equal to 10% of the whole number of pixels, and the peak is not present above the second threshold, andwherein the highly contrasted image is an image in which the peak is present one of a range below the first threshold and a range above the second threshold and another peak is present in the other.
1 Assignment
0 Petitions
Accused Products
Abstract
In an image data conversion device, color image data is represented in gray scale, a histogram of brightness values is created for the gray-scaled image data, it is determined based on the created histogram which image pattern of a plurality of image patterns the gray-scaled image data is classified into, a range subjected to gamma correction and a range fixed to at least one of a minimum value and a maximum value of gray scale are set for each image pattern, and image data conversion including the gamma correction is performed on the gray-scaled image data.
2 Citations
12 Claims
-
1. An image data conversion device that represents color image data in gray scale to convert the color image data to black-and-white image data, the image data conversion device comprising:
-
gray scale operation unit configured to represent the color image data in gray scale; histogram creation unit configured to create a histogram of brightness values for gray-scaled image data; determination unit configured to, based on created histogram, determine which image pattern of image patterns of bright image, a dark image, a highly contrasted image whose contrast that is a difference in a brightness between a bright portion and a dark portion is significantly large, and an image which is not included in any of the bright image, the dark image, and the highly contrasted image the gray-scaled image data is classified into; and image data conversion unit configured to, in accordance with which image of the bright image, the dark image, the highly contrasted image, and the image not included any of the above a determined image pattern is classified into, set a brightness value range on which gamma correction is performed for the gray-scaled image data, set a brightness value range on which correction for fixing a brightness value to at least one of a minimum value and a maximum value of gray scale is performed for the gray-scaled image data, and perform image data conversion including the gamma correction and correction for fixing a brightness value to at least one of the minimum value and the maximum value of the gray scale for the gray-scaled image data, wherein the bright image is an image in which a peak having the highest brightness value is present above a second threshold greater than a first threshold of a brightness value in the histogram and the peak is not present below the first threshold, wherein the dark image is an image in which the peak is present below the first threshold, the total number of pixels above the first threshold is greater than or equal to 10% of the whole number of pixels, and the peak is not present above the second threshold, and wherein the highly contrasted image is an image in which the peak is present one of a range below the first threshold and a range above the second threshold and another peak is present in the other. - View Dependent Claims (2, 3, 4, 5, 9, 10, 12)
-
-
6. (canceled)
-
7. An image data conversion method of an image data conversion device that represents color image data in gray scale to convert the color image data to black-and-white image data, the image data conversion method comprising:
-
representing the color image data in gray scale; creating a histogram of brightness values for a gray-scaled image data; based on a created histogram, determining which image pattern of image patterns of bright image, a dark image, a highly contrasted image whose contrast that is a difference in a brightness between a bright portion and a dark portion is significantly large, and an image which is not included in any of the bright image, the dark image, and the highly contrasted image the gray-scaled image data is classified into; and in accordance with which image of the bright image, the dark image, the highly contrasted image, and the image not included any of the above a determined image pattern is classified into, setting a brightness value range on which gamma correction is performed for the gray-scaled image data, setting a brightness value range on which correction for fixing a brightness value to at least one of a minimum value and a maximum value of gray scale is performed for the gray-scaled image data, and performing image data conversion including the gamma correction and correction for fixing a brightness value to at least one of the minimum value and the maximum value of the gray scale for the gray-scaled image data, wherein the bright image is an image in which a peak having the highest brightness value is present above a second threshold greater than a first threshold of a brightness value in the histogram and the peak is not present below the first threshold, wherein the dark image is an image in which the peak is present below the first threshold, the total number of pixels above the first threshold is greater than or equal to 10% of the whole number of pixels, and the peak is not present above the second threshold, and wherein the highly contrasted image is an image in which the peak is present one of a range below the first threshold and a range above the second threshold and another peak is present in the other.
-
-
8. A non-transitory storage medium storing an image data conversion program that causes a computer as an image data conversion device that represents the color image data by gray scale to convert the color image data to black-and-white image data to execute:
-
representing the color image data in gray scale; creating a histogram of brightness values for a gray-scaled image data; based on a created histogram, determining which image pattern of image patterns of bright image, a dark image, a highly contrasted image whose contrast that is a difference in a brightness between a bright portion and a dark portion is significantly large, and an image which is not included in any of the bright image, the dark image, and the highly contrasted image the gray-scaled image data is classified into; and in accordance with which image of the bright image, the dark image, the highly contrasted image, and the image not included any of the above a determined image pattern is classified into, setting a brightness value range on which gamma correction is performed for the gray-scaled image data, setting a brightness value range on which correction for fixing a brightness value to at least one of a minimum value and a maximum value of gray scale is performed for the gray-scaled image data, and performing image data conversion including the gamma correction and correction for fixing a brightness value to at least one of the minimum value and the maximum value of the gray scale for the gray-scaled image data, wherein the bright image is an image in which a peak having the highest brightness value is present above a second threshold greater than a first threshold of a brightness value in the histogram and the peak is not present below the first threshold, wherein the dark image is an image in which the peak is present below the first threshold, the total number of pixels above the first threshold is greater than or equal to 10% of the whole number of pixels, and the peak is not present above the second threshold, and wherein the highly contrasted image is an image in which the peak is present one of a range below the first threshold and a range above the second threshold and another peak is present in the other. - View Dependent Claims (11)
-
Specification