A controller extracts an image resolution in a first direction of image data stored in a memory; determines, based on the image data, whether a code image is included in an image to be printed on a recording medium, the code image being formed with a plurality of print regions and a plurality of non-print regions; in response to determining that the code image is included, determines whether a print resolution in the first direction is lower than the extracted image resolution in the first direction; in response to determining that the print resolution is lower than the extracted image resolution, updates the print resolution in the first direction with a value equal to or higher than the extracted image resolution in the first direction; and controls a print engine to perform printing on the recording medium with the updated print resolution in the first direction.