Edge detection apparatus and edge detection method

An edge detection method, comprising:

• a detection step of detecting a dispersion degree of gradation values of input image data whose resolution is lower than an output resolution;
• a determination step of determining detection sensitivity, which is edge detectability, based on the dispersion degree detected in the detection step;
• an edge detection step of detecting an edge from an input image based on the input image data, at the detection sensitivity determined in the determination step;
• and
• a scaling step of outputting image data generated by converting the input image data to the output resolution in accordance with the detected edge, wherein
• with respect to first and second cases in which the dispersion degree is lower in the first case than the dispersion degree in the second case, the determination step determines a detection sensitivity that is lower in the first case and higher in the second case.

A non-transitory computer readable medium that stores a program, wherein

• the program causes a computer to execute:
• a detection step of detecting a dispersion degree of gradation values of input image data whose resolution is lower than an output resolution;
• a determination step of determining detection sensitivity, which is edge detectability, based on the dispersion degree detected in the detection step;
• an edge detection step of detecting an edge from an input image based on the input image data, at the detection sensitivity determined in the determination step;
• and
• a scaling step of outputting image data generated by converting the input image data to the output resolution in accordance with the detected edge, wherein
• with respect to first and second cases in which the dispersion degree is lower in the first case than the dispersion degree in the second case, the determination step determines a detection sensitivity that is lower in the first case and higher in the second case.

An edge detection apparatus, comprising at least one processor that operates as:

• a detection unit configured to detect a dispersion degree of gradation values of input image data whose resolution is lower than an output resolution;
• a determination unit configured to determine detection sensitivity, which is edge detectability, based on the dispersion degree detected by the detection unit;
• an edge detection unit configured to detect an edge from an input image based on the input image data, at the detection sensitivity determined by the determination unit;
• and
• a scaling unit configured to output image data generated by converting the input image data to the output resolution in accordance with the detected edge, wherein
• with respect to first and second cases in which the dispersion degree is lower in the first case than the dispersion degree in the second case, the determination unit determines a detection sensitivity that is lower in the first case and higher in the second case.