Apparatus and method for processing image signal, imaging apparatus, and method for displaying image

An image processing method comprising:

• down-converting, with one or more processors, an input image signal in a first resolution into a down-converted image signal in a second resolution that is lower than the first resolution,
• in parallel to down-converting the input image signal in the first resolution into the down-converted image signal in the second resolution, performing, with the one or more processors, a filtering process on the input image signal in the first resolution to output a high frequency band edge signal by extracting components in a high frequency band,
• down-converting, with the one or more processors, the high frequency band edge signal into a down-converted high frequency band edge signal in the second resolution, and
• combining, with the one or more processors, the down-converted high frequency band edge signal in the second resolution with the down-converted image signal in the second resolution so as to obtain an output image signal in the second resolution.

A non-transitory computer-readable medium comprising an image processing program that, when executed by one or more processors, performs a set of operations comprising:

• down-converting an input image signal in a first resolution into a down-converted image signal in a second resolution that is lower than the first resolution,
• in parallel to down-converting the input image signal in the first resolution into the down-converted image signal in the second resolution, performing a filtering process on the input image signal in the first resolution to output a high frequency band edge signal by extracting components in a high frequency band,
• down-converting the high frequency band edge signal into a down-converted high frequency band edge signal in the second resolution, and
• combining the down-converted high frequency band edge signal in the second resolution with the down-converted image signal in the second resolution so as to obtain an output image signal in the second resolution.

A camera apparatus comprising:

• an imaging unit configured to output an image signal in a first resolution;
• and
• one or more processors configured to:
• receive the image signal that is output from the imaging unit as an input image signal in the first resolution,
• down-convert the input image signal in the first resolution into a down-converted image signal in a second resolution that is lower than the first resolution,
• in parallel to down-converting the input image signal in the first resolution into the down-converted image signal in the second resolution, perform filtering process on the input image signal in the first resolution to output a high frequency band edge signal by extracting components in a high frequency band,
• down-convert the high frequency band edge signal into a down-converted high frequency band edge signal in the second resolution, and
• control combining the down-converted high frequency band edge signal in the second resolution with the down-converted image signal in the second resolution so as to obtain an output image signal in the second resolution.