Digital images are very easy to copy, edit, and place within one's own work—so easy that many users ignore the copyrights that protect these images from unauthorized use and distribution. Some artists have turned to technological means to thwart illegal copying of their work. The digital watermark is one of these methods. An original digital artwork is loaded into special software that subtlely modifies the image to insert the watermark. The changes are invisible to the human eye, but the same software can detect an image that contains the watermark, even after the image has been compressed, cropped, or rotated (with certain limits). This allows artwork owners to discover any illegal uses of their art and to prove that the artwork was their own.