1. An image-providing apparatus providing image data used for printing to a printing apparatus, the image-providing apparatus comprising: a generation unit adapted to generate image data used for printing from data of an original image; and a communication unit adapted to provide the image data used for printing to a connected printing apparatus, wherein, when the original image is rotated during generation of the image data used for printing, the generation unit, along with obtaining a rotated image by rotating the original image, generates image data used for printing by including achromatic pixels or pixels from non-overlapping regions that do not overlap with a region corresponding to the original image within the rotated image in blank regions of the rotated image, and wherein the generation unit generates partial images by geometric transformation of the non-overlapping regions and generates the image data used for printing by compositing the generated partial images with regions of corresponding shapes among the blank regions.