1. An image processing apparatus comprising a computer, the computer programmed to: generate a sample texture image having a texture component by extracting the texture component from a transform target image; generate a texture image including first pixels to each of which a pixel value is not yet assigned and second pixels to which pixel values are assigned, the texture image having a size greater than a size of the sample texture image; select one of the first pixels as a processing target pixel; determine a preset search range within the sample texture image, the preset search range including a first location corresponding to a second location of the processing target pixel; search for a third pixel in the preset search range, a value calculated based on differences between pixels around the third pixel and the second pixels located around the processing target pixel being less than a threshold; and assign a pixel value of the third pixel to the processing target pixel.