1. A raw-cost calculation apparatus using an adaptive window mask, the apparatus comprising: an image acquirer configured to acquire image information that includes pattern and texture information of a reference image, and pattern and texture information of a target image; a window generator configured to generate a plurality of windows, each including at least one pixel, by receiving the texture information, included in the acquired image information, from a user, or by dividing the texture information by a predetermined size; a window mask generator configured to generate a window mask, which has a same size as a size of the generated windows, and is capable of converting the pattern information, included in the acquired image information, according to a predetermined algorithm; a window masker configured to perform masking of the reference image and the target image the by using the generated window mask to convert the pattern information of the reference image and the pattern information of the target image included in the acquired image information; and a raw-cost calculator configured to match pattern information of the masked reference image and pattern information of the masked target image to calculate a difference, and to calculate a raw cost based on the difference.