A New Watermarking Algorithm for Color Satellite Images Using Color Logos and Hash Functions

This paper deals with a new robust and fragile watermarking algorithm which embeds 3bit index map of color logo watermark in the frequency domain and fragile information in the spatial domain of 24bit satellite color images. The color logo is used for copyright protection and the hash functions are used for checking the authenticity of the satellite image. The new algorithm caused minimal invisible distortion to the images demonstrated by high peak signal to noise ratio and similarity structure index measure values. The new watermarking technique has been successfully tested on a variety of satellite images. The robust watermarking scheme survived many attacks such as JPEG compression, resizing and rotation while the fragile watermark is very sensitive to the slightest modification to any RGB pixel, also it can accurately locate the tampered areas on the satellite color images.