Image signal processor with adaptive noise reduction and an image signal processing method therefor

An image signal processing device for executing signal processing on image data representative of an input image, said device comprising:

• a signal processing circuit for executing signal processing on the image data for correction and recording, and executing noise reduction on individual image data in accordance with at least one of image inputting conditions and a pixel level;
• said signal processing circuit comprising:
• a threshold generating circuit for generating a threshold by taking account of at least one of the image inputting conditions and the pixel level;
• and
• a noise reducing circuit for producing, during the noise reduction, a difference in level between subject pixel data whose noise is to be detected and a mean value of said subject pixel data and pixel data around said subject pixel data, and selecting either one of said subject pixel data and said mean value in accordance with said difference and the threshold.