A controller converts the original image data into converted image data representing a first converted image, analyzes the original image data and counts a number of first characters recognized in the original image represented by the original image data, and analyzes the converted image data and count a number of second characters recognized in the converted image represented by the first converted image data. The controller compares the number of first characters with the number of second characters and determine which one of the number of first characters and the number of second characters is greater than the other. The controller outputs the original image data when the controller determines that the number of first characters is greater than the number of second characters, and outputs the converted image data when the controller determines that the number of second characters is greater than the number of first characters.