Image-processing method and recording medium in which such an image-processing method is recorded

An image-processing method, which carries out a sharpening process by subtracting second-order differential with respect to each pixel, obtained by defining the distribution of image data of an original image as a function, from the image data of the original image,

• wherein:
• the second-order differential is obtained by the sum total of differences in value between a target pixel and a plurality of pixels in the vicinity thereof, and each of the differences is multiplied by a coefficient, with the coefficient being varied depending on the size of the corresponding difference.

An image-processing, which carries out a sharpening process by subtracting second-order differential with respect to each pixel, obtained by defining the distribution of image data of an original image as a function, from the image data of the original image,

• wherein the second-order differential is provided with an upper limit and/or a lower limit, and the degree of the sharpening process is controlled by altering a third parameter for determining the upper limit and/or the lower limit.

A recording medium, which has an image-processing program recorded therein, the image-processing program being arranged to allow a computer to carry out a sharpening process by subtracting second-order differential with respect to each pixel, obtained by defining the distribution of image data of an original image as a function, from the image data of the original image,

• wherein the computer is allowed to execute a process for controlling the degree of the sharpening process altering a first parameter for determining the size of the second-order differential to be subtracted from the image data of the original image.

A recording medium, which has an image-processing program recorded therein, the image-processing program being arranged to allow a computer to carry out a sharpening process by subtracting second-order differential with respect to each pixel, obtained by defining the distribution of image data of an original image as a function, from the image data of the original image,

• the computer being allowed to execute a process wherein:
• the second-order differential is obtained by the sum total of differences between a target pixel and a plurality of pixels in the vicinity thereof, and each of the differences is multiplied by a coefficient, with the coefficient being varied depending on the size of the corresponding difference.

A recording medium, which has an image-processing program recorded therein, the image-processing program being arranged to allow a computer to carry out a sharpening process by subtracting second-order differential with respect to each pixel, obtained by defining the distribution of image data of an original image as a function, from the image data of the original image,

• the computer being allowed to execute a process wherein:
• the second-order differential is provided with an upper limit and/or a lower limit, and the degree of the sharpening process is controlled by altering a third parameter for determining the upper limit and/or the lower limit.