1. An image processing apparatus comprising: an input unit that inputs printing information containing image data; and a conversion unit that, when the pixel value of the top pixel from among successive N pixels (N is an integer equal to or larger than 2) of the image data is a specific value, sets a pixel having a pixel value that is not the specific value as a new top pixel from among pixels from a pixel adjacent to the top pixel to the N-th pixel, refers to data of the new top pixel to the N-th pixel, and performs a conversion into pixel values that are calculated with coefficient values according to the magnitude of the pixel values.