Image tamper detection and self-recovery using multiple median watermarking

Photographs play a very crucial role in our lives, be it in the field of forensic investigation, military intelligence, scientific research, and publications. Nowadays, most of these photographs are in the digital format; which can be easily edited in any photo editing software without requiring any special knowledge of the field. It has become quite hard to identify whether an image is real or fake. This can be very crucial in the cases of forensic investigation or authorization of images. So, we need a solution, which not only identifies the attacks from different schemes like collage attack, crop attack, etc. but also recovers the edited or tampered portion. In proposed work, 4 reduced-size copy of the original image is hidden in the original image's 4-LSB using four pseudo-random codes. Later on, these copies are used for tamper detection. As image gets tampered, recovery images (which are stored in the 4-LSB's of the original image) also get tampered. So, before recovering the edited portion using the median image (or one out of the four recovery images) various filters like median filters, sharpening filters, and noise removal filters are used to enhance the quality. The proposed scheme recovers the host better than the many recently proposed schemes.