Image processing system, image processing method, and image processing program

摘要

There is provided an image processing system which can remove jaggies not only from binary images but also from gray scale images, color images and images upscaled by an unknown scaler. When the center pixel of the local area clipped from a processing target image is decided to be the jaggy removal target pixel, a base filter computing means 84 applies a plurality of types of predetermined base filters to the local area. A weight calculating means 85 calculates weights with respect to the plurality of types of base filters based on the feature amount calculated by a principal component analyzing means 82. Based on a filtering result of each base filter and a weight with respect to each base filter, a filtering result weight computing means 86 updates a pixel value of the center pixel.

主权项

1. An image processing system comprising:
a brightness gradient calculating unit which calculates a brightness gradient of each pixel in a local area clipped from a processing target image; a principal component analyzing unit which analyzes a principal component of the brightness gradient of each pixel in the local area, and calculates a feature amount which represents a distribution of brightness gradients; a target pixel deciding unit which, based on a brightness gradient of a center pixel of the local area and the feature amount calculated by the principal component analyzing unit, decides whether or not the center pixel is a jaggy removal target pixel; a target pixel detail deciding unit which transforms each pixel value of each pixel, which is sampled based on a pixel decided as the jaggy removal target pixel by the target pixel deciding unit, into a frequency domain, and decides whether or not intensity equal to or more than a threshold can be obtained at an arbitrary frequency; a base filter computing unit which, when the center pixel of the local area is decided to be the jaggy removal target pixel, applies a plurality of types of predetermined base filters to the local area; a weight calculating unit which calculates a weight with respect to the plurality of types of base filters based on the feature amount calculated by the principal component analyzing unit; and a filtering result weight computing unit which, based on a result that the plurality of types of base filters is applied to the local area and the weight with respect to the plurality of types of base filters, determines a pixel value of a pixel which is included in a corrected image created as an image by correcting a processing target image and which corresponds to the center pixel of the local area.