A digital camera includes a printing system including an image receiving module for receiving a first image, a selection module, a availability, a comparison module, a size module, an image forming module, and an image output module. The selection module can allow selection of a desired print size for the first image. The availability module can determining available paper sizes of a printer connected to the digital camera. The comparison module can determine whether the printer supports the desired print size input to the selection module. The size module is capable of selecting a paper size from the available paper sizes bigger than the desired print size, if the printer doesn't support the desired print size. And then, the image forming module resizes the first image to form a second image. The image output module is capable of outputting the second image to the printer.