Encoding of Color Images in DWT domain using FrFT

Abstract

This paper presents a new color image encoding and decoding technique using Fractional Fourier Transform (FrFT) and Discrete Wavelet Transform (DWT). In proposed work, all three planes of color images are encoded using subbands of DWT and parameters of FrFT. Selection of subband (among the subbands obtained after applying DWT) for applying FrFT and parameters of FrFT are used as security key for the purpose of encoding and decoding of all three color channels. For ensuring the correct decoding of color images, the knowledge of correct selection of subband of DWT for applying FrFT and exact values of FrFT parameters is required. Correct decoding is not possible without the correct knowledge of DWT subband and FrFT parameters values. The proposed technique is also compared with one of the recent existing techniques and experimental results are used to show the effectiveness of the proposed technique.