1. An image processing device comprising: an estimating portion estimating, based on first image data obtained through imaging, using an imaging device, a first image that includes a specific image pattern, and based on second image data, obtained by imaging, using the imaging device, second image data that does not include the specific image pattern, a frequency component of noise that is included in both the first and second images, and a frequency component of a first image that does not include said noise; and a controlling portion controlling weighting, relative to frequencies, when calculating a correlation between the first image data and third image data, obtained through imaging a third image through the imaging device, based on the individual frequency components estimated by the estimating portion.