Provided is an image processing apparatus and image processing method that make it possible to reduce jaggedness and blurring that may occur when performing resolution conversion of an inputted image from low resolution to high resolution, and make it possible to output a high-resolution image. When performing the conversion from low resolution to high resolution, a multi-gradation signal value pattern that surround a pixel of interest for which interpolation is being performed is acquired. By performing pattern matching, a pattern that corresponds to the acquired signal value pattern is extracted from among pattern files that are prepared in advance for the acquired signal value pattern, after which the image is converted to high resolution by signal value substitution and then outputted.