Software and lasers are used in finishing apparel to produce a desired wear pattern or other design. A technique includes determining a fabric's response to a laser, capturing an initial image of a wear pattern on a garment, and processing the initial image to obtain a working image in grayscale. The working image is further processed to obtain a difference image by comparing each pixel relative to a dark reference. The difference image is converted to a laser values image by using the previously determined fabric response to the laser.