Image device and method for removing noise

An image capturing apparatus for capturing an object using a solid-state imaging device, comprising:

• subtraction means for subtracting second image data, which is captured with a shutter closed under a same exposure condition as an ordinary capturing, immediately before or after thereof and digitalized, from first image data, which is captured by an ordinary capturing mode with the shutter opened and digitalized;
• adder means for adding an offset, for negative noise, to a signal value from said subtraction means;
• limiter means for limiting a signal level from said adder means;
• bright spot position detection means for detecting an occurrence position of a bright spot noise, which is a high level noise which produces a bright spot on a captured image, in said second image data;
• and
• noise compensation means for compensating for data of a pixel corresponding to the occurrence position of said bright spot noise detected by said bright spot position detection means, with respect to output data from said limiter means, wherein:
• said bright spot position detection means detects the occurrence position of said bright spot noise if a value, obtained by subtracting an average signal level of two pixels adjacent to said pixel from a signal level of said pixel, reaches the predetermined value.

An image capturing apparatus for capturing an object using a solid-state imaging device, comprising:

• subtraction means for subtracting second image data, which is captured with a shutter closed under a same exposure condition as an ordinary capturing, immediately before or after thereof and digitalized, from first image data, which is captured by an ordinary capturing mode with the shutter opened and digitalized;
• adder means for adding an offset, for negative noise, to a signal value from said subtraction means;
• limiter means for limiting a signal level from said adder means;
• bright spot position detection means for detecting an occurrence position of a bright spot noise, which is a high level noise which produces a bright spot on a captured image, in said second image data;
• and
• noise compensation means for compensating for data of a pixel corresponding to the occurrence position of said bright spot noise detected by said bright spot position detection means, with respect to output data from said limiter means,
• wherein said bright spot position detection means detects the occurrence position of said bright spot noise if a value, obtained by subtracting a signal level of either one of pixels adjacent to said pixel from a signal level of said pixel reaches the predetermined value.

A noise elimination method for eliminating a noise occurring at a time of capturing an object using a solid-state imaging device, comprising the steps of:

• subtracting, from first image data which is captured by an ordinary capturing mode with a shutter opened and then digitalized, second image data which is captured immediately before or after the ordinary capturing with a shutter closed in a same exposure condition as said ordinary capturing and then digitalized;
• adding an offset for a negative noise to data resulting from said subtraction;
• limiting a signal level of the offset data;
• detecting an occurrence position of a bright spot noise in said second image data, which is a high level noise which produces a bright spot on a captured image, if a signal level of a pixel in said second pixel data reaches a predetermined value;
• and
• compensating for data of said pixel corresponding to the occurrence position of said bright spot noise detected, with respect to data resulting from said limiting.