A method for controlling an image capturing device includes: calculating luminance data of a first image to generate a plurality of first characteristic values, and calculating luminance data of a second image to generate a plurality of second characteristic values; calculating a plurality of motion values of a plurality of blocks of the second image according to the luminance data of the first image and the luminance data of the second image; determining a plurality of ratio parameters corresponding to the blocks of the second image according to the motion values; generating a plurality of adjusted second characteristic values according to the ratio parameters, the second characteristic values and the first characteristic values; and generating an adjustment signal for controlling the image capturing device according to the adjusted second characteristic values.