Method and apparatus for reducing effects of dark current and defective pixels in an imaging device

An image processing apparatus comprising:

• a memory device for storing at least one actual image, at least one dark current reference image, and at least one white reference image captured by a pixel array, the storage system further storing a plurality of gain conditions and a plurality of exposure times associated with the at least one actual image and a plurality of gain conditions and a plurality of exposure times associated with the at least one dark current reference image and the at least one white reference image;
• and
• a processor coupled to the storage system for compensating the at least one actual image by identifying defective pixels of the at least one actual image based on at least one gain condition of the stored plurality of gain conditions associated with the at least one dark current reference image and the at least one white reference image, and at least one exposure time of the stored plurality of exposure times associated with the at least one dark current reference image and the at least one white reference image, applying at least one defective pixel compensation process to the identified defective pixels, capturing a plurality of white reference images under a plurality of gain conditions and exposure times for creating a respective defective pixel reference image, and for each combination of gain conditions and exposure times, identifying locations of defective pixels that need compensation.

A digital camera comprising:

• an image compensation apparatus having:
• a memory device for storing at least one actual image, at least one dark current reference image, and at least one white reference image captured by a pixel array, the storage system further storing a plurality of gain conditions and a plurality of exposure times associated with the at least one actual image and a plurality of gain conditions and a plurality of exposure times associated with the at least one dark current reference image and the at least one white reference image;
• and
• a processor coupled to the storage system for compensating the at least one actual image by identifying defective pixels of the at least one actual image based on at least one gain condition of the stored plurality of gain conditions associated with the at least one dark current reference image and the at least one white reference image, and at least one exposure time of the stored plurality of exposure times associated with the at least one dark current reference image and the at least one white reference image, and applying at least one defective pixel compensation process to the identified defective pixels.