Image processing method and computer program

An image processing method for adjusting a size of an image signal of each pixel included in an input image by a computer according to a predetermined purpose, the image processing method comprising the steps of:

• (Sa1) inputting data of an input image into a computer;
• (Sa2) inputting an arbitrarily defined constant m as a contrast intensity;
• (Sa3) demarcating a closed region made up of a plurality of pixels in the input image as a target region D, summing degrees of inclination between respective two pixels, namely, a pixel of interest in the target region D and arbitrarily defined neighboring pixels thereof, over a whole circumference around the pixel of interest, and dividing the sum by the number of pixels within the target region to calculate a mean value thereof, wherein the mean value is an amplitude β of a gradient;
• and
• (Sa4) multiplying the amplitude value β of a gradient obtained in step (Sa3) by the contrast intensity m (where m is a positive constant) inputted in step (Sa2) and adding an arbitrarily defined offset value γ to the obtained value,
• wherein
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• i is an index corresponding to a first spatial dimension,
• j is an index corresponding to a second spatial dimension,
• k is an arbitrarily defined boundary constant greater than or equal to one,
• x(i, j) corresponds to the pixels of the target region D,
• target region D is bounded in one corner by a pixel corresponding to x(i=−k, j=−k) and in another corner by a pixel corresponding to x(i=k, j=k),
• N is the number of pixels in the target region D,
• x(j=0, j=0) corresponds to the pixel of interest in the target region D, and
• x(i≠0, j≠0) corresponds to the arbitrarily defined neighboring pixels of target region D;
• the method further including repeating (Sa3) and (Sa4) with respect to a new target region D and new pixel of interest in the new target region D.