Patent ID: 8477182

Claim:
An endoscope apparatus, comprising: a region dividing portion that divides an endoscope image into a center region and a peripheral region; a brightness mean value calculation portion that has a peripheral brightness mean value calculation portion that calculates a peripheral brightness mean value that indicates a mean value of a brightness of the peripheral region, and a center brightness mean value calculation portion that calculates a center brightness mean value that indicates a mean value of a brightness of the center region; a first weighting factor calculation portion that calculates a first weighting factor α (where 0<α<1) based on a ratio between the center brightness mean value and the peripheral brightness mean value; a first photometric value calculation portion that calculates a first photometric value based on a sum total of a value obtained by multiplying the center brightness mean value by the first weighting factor α and a value obtained by multiplying the peripheral brightness mean value by (1−α); and a brightness adjustment control portion that generates a brightness adjustment control signal that adjusts a brightness of the endoscope image based on the first photometric value; wherein when the ratio between the peripheral brightness mean value and the center brightness mean value is in a predetermined range that is centered around a value of 1, even if the ratio changes, the weighting factor calculation portion calculates the first weighting factor α of a same value.