The proposed new partial encryption schemes use a secure encryption algorithm to encrypt only part of the compressed data. After application of image compression algorithm the partial encryption will applied. For two pairs of different gray scale images with the size (256ยด256) pixels, only 0.0244%-25% of the original data is encrypted. As a result, we see a significant reduction of time in the stage of encryption and decryption. In the compression step, Firstly, stereo images were transformed using Discrete Wavelet Transform (DWT) in order to reduce computation time, then the disparities between these images were estimated by the Two Dimensional Logarithmic (TDL) algorithm for motion estimation (the different between stereo images) is used. The result of the Motion Vector (MV) and still image were encrypted by RSA algorithm. The decoded images then compared with the original images. Good results showed in the experimental results of Peak Signal-to-Noise Ratio (PSNR), Compression Ratio (CR) and processing time. The proposed schemes of partial encryption are fast, secure and not be reducing in compression performance of the selected compression methods.
Volume 11 | 01-Special Issue
Pages: 1811-1817