Edge-based sharpness strength control circuit, image sensing device and operation method of the same

An image sensing device, comprising:

• an image sensor including a pixel array having a plurality of pixels;
• an image signal processor suitable for processing signal output from the image sensor;
• wherein one of the image sensor and image signal processor includes an edge-based sharpness strength control circuit that comprises:
• a first edge determination unit suitable for determining each of multiple regions in a pixel array to be an edge region having edge information or a flat region having flat information on pixel data of the corresponding region, the pixel array including a plurality of pixels;
• a second edge determination unit suitable for determining each edge region to be a step edge region having directional information or a texture edge region having non-directional information within the corresponding edge region;
• and
• a noise removing unit suitable for removing noise from each step edge region using a first filter and for removing noise from each texture edge region using a second filter having a different gain than that of first filter.

An operation method of an image sensing device, comprising:

• determining each of multiple regions in a pixel array to be an edge region when a standard deviation of the pixel data of neighboring pixels within the corresponding region is greater than a reference value, and to be a flat region when the standard deviation of the pixel data of the neighboring pixels within the corresponding region is less than the reference value;
• determining each edge region to be a step edge region when a total number of directional changes in the corresponding edge region is less than a set value, and to be a texture edge region when the total number of direction changes in the corresponding edge region is greater than the set value;
• and
• removing noise from each step edge region using a first filter and for removing noise from each texture edge region using a second filter having a different gain than that of the first filter.