1. An image processing device comprising: a processor configured to: generate text image data representing a text image based on original image data representing an original image; and generate background image data representing a background image based on the original image data, wherein the background image represents an image in which text in the original image has disappeared, wherein to generate background image data representing the background image data based on the original image data, the processor is configured to: generate distribution data representing a tone value distribution of target image data as a processing target; determine a specific range on the distribution data; perform a correction process on the target image data for setting a value of a first-type pixel having a tone value within the specific range before the correction process is performed to a tone value within the specific range after the correction process is performed, and setting a value of a second-type pixel having a tone value out of the specific range before the correction process is performed to a tone value within the specific range after the correction process is performed, wherein the specific range includes a plurality of consecutive tone values, wherein the plurality of consecutive tone values included within the specific range include a peak tone value that is included in a tone value distribution of the original image data and corresponds to a background of the text; and wherein, to determine the specific range, the processor is configured to: set a first width of the specific range, the first width determined from first distribution data representing a first dispersion of values of a plurality of pixels representing a background in the target image data; and set a second width of the specific range, the second width determined from second distribution at a representing a second dispersion of values of the plurality of pixels representing the background in the target image data, the second dispersion being larger than the first dispersion; wherein the second width is larger than the first width.