Protection of Thermal Images using Novel Image Encryption and Decryption Algorithms

Abstract

This proposed research aims at developing a novel thermal image encryption newlinealgorithms and region of interest based thermal image encryption algorithms. This newlineresearch concern is an investigation on full thermal image and selective thermal image newlineencryption algorithms. This will precede with already existing and hence provide a hybrid newlineconcept for better encryption. Encryption can be done in two ways; one way is by newlinescrambling the pixel position and other way is by pixel value manipulation. In this newlineresearch used both approaches for better encryption. For better security there must be an newlineencrypting key or password in the hybrid encryption algorithm. newlineBased on that, proposed a thermal image encryption based on Region of Interest newline(ROI) and chaotic map. Firstly, extract the MSB bit plane of thermal input image. These newlineMSB bit planes undergo ROI calculation method. This method involves the partition of newlineMSB bit plane into several 16*16 blocks. Apply the threshold function to each block to newlineseparate the ROI blocks. Then selected part from the input thermal image undergoes XOR newlineoperation between random images generated from chaotic map. For loss-less decryption newlineat the receiver side, embedded the index of ROI blocks using LSB embedding algorithm. newlineThe simulation results show that the proposed algorithm achieves good security and more newlineefficiency. newlineThe adopted technique having pixel level and bit level permutation process. To newlinereduce time and computational complexity, a partial encryption technique is adopted. newlineArnold cat map technique involved in the pixel level permutation process to decrease newlinecorrelation of original image. The proposed scheme selects only higher four binary planes newlinefor the bit level shuffling process. This process consists of row and column wise circular newlineshift operation with the help of pseudo random numbers generated from chaotic map newlinesystem. Mixing of binary planes of the thermal image will lead to prevent the differential newlineattacks. An experimental result shows that proposed scheme exhibits good performance in newlineterms entropy, Number of Pixel Change Rate (NPCR) and the speed of system. newline