Success

The success of the steganography algorithm is twofold: no change in the image's size on disk, and no change in appearance. The only way to detect that the image has been modified is by using a computer to compare it to an image that is positively known to be the original. Because of the uncertainty of the reason for the differences between the two images, it may not be realized that the steganographic data is there. For example, if the original image were converted to another file type and then converted back, some changes in the pixel values might occur. This leaves reasonable doubt to an outsider that the changes may not indicate steganography.