A digital image sensor comprising an array of pixels and a processor is
provided. The array of pixels comprises a current pixel in a first color
plane that is configured to produce a current sensor value, a first
plurality of pixels in the first color plane that is configured to
produce a first plurality of sensor values, and a second plurality of
pixels in the second color plane that is configured to produce a second
plurality of sensor values. The processor is configured to generate a
plurality of estimate values using the first plurality of sensor values
and a plurality of intensity ratios associated with the second plurality
of sensor values, and the processor is configured to determine whether
the current pixel is defective using the plurality of estimate values and
the current sensor value.