IMAGE PROCESSING DEVICE THAT EFFICIENTLY PERFORMS LOGARITHM CALCULATION IN RETINEX PROCESS

摘要

A storage unit stores a table including a plurality of logarithmic values corresponding to respective ones of a plurality of antilogarithmic values. An antilogarithmic-value calculating portion divides a pixel value of a subject pixel in an original image by a peripheral average luminance of the subject pixel, thereby calculating a desired antilogarithmic value. A determining portion determines whether the desired antilogarithmic value is included in a predetermined range. A first logarithmic-value calculating portion calculates a desired logarithmic value corresponding to the desired antilogarithmic value by referring to the table when the determining portion determines that the desired antilogarithmic value is included in the predetermined range. A second logarithmic-value calculating portion calculates the desired logarithmic value based on a linear function when the determining portion determines that the desired antilogarithmic value is outside the predetermined range.