Patent ID: 8913161

Claim:
An image capturing apparatus comprising: an image sensing element including an effective pixel portion in which a plurality of pixels are two-dimensionally arrayed in a row direction and a column direction, and a shading pixel portion provided on at least one line at an end portion of said effective pixel portion in the row direction or the column direction; a setting unit configured to variably set, in at least one of the row direction and the column direction, an effective pixel signal readout region in which effective pixel signals are read out from said effective pixel portion, and a shading pixel signal readout region in which shading pixel signals are read out from said shading pixel portion; a readout unit configured to read out the effective pixel signals from the effective pixel signal readout region, and read out the shading pixel signals from the shading pixel signal readout region; a correction data generation unit configured to generate correction data for each column or each row based on the shading pixel signals read out by said readout unit; a correction data storage unit configured to store the correction data generated by the correction data generation unit; a correction unit configured to correct luminance levels of the effective pixel signals, read out by said readout unit, for each column or each row using the correction data; and a control unit configured to control said setting unit so that the shading pixel signal readout region becomes wider than the effective pixel signal readout region, wherein in a case that the effective pixel signal readout region and shading pixel signal readout region set by the setting unit are changed, the correction data generation unit generates correction data based on the shading pixel signals read out from the shading pixel signal readout region changed by the control unit and updates the correction data that has been already stored in the correction data storage unit to latest correction data, and the correction unit corrects luminance levels of the effective pixel signals by using the difference between the correction data corresponding to the changed shading pixel signal readout region and the effective pixel signals read out from the effective pixel signal readout region.