Encryption then Compression Based on Image Fusion, Chaotic Map and DNA Subsequence Operation. Initially two or more similar images are combined into a single image and the fused image is more informative than the input images. This is used for image enhancement. After image fusion the Chaotic map is used to generate the chaotic sequence which is then used for DNA Encoding. The image is the sent to the receiver in encrypted form. At the receiver end the image is initially decoded using the DNA Subsequence operation. It is followed by realization of the chaotic sequence, then the splitting up of the fused image is done to get back the original image.