A chaos based symmetric key partial encryptio of 8 bit/pixel grayscale image has been proposed. An original image is first decomposed into its 8 binary bitplanes among which the significant ones are non-adaptively determined. The significant bitplanes are encrypted with the key stream generated by a "Cross Coupled Chaotic random bit Generator" and then combined with the uncrypted ones to from the cipher image. Performance of the technique is verified bt tests based on image statistics- Key sensitive and impermeability of cipher image.
Python 3 and Jupyter Notebook