A robust perceptual colour image compression with watermarking
N. Surabhi, Sreeleja N Unnithan · 2017
The development of multimedia and digital technology has led to the requirement of high quantity of data to represent images. Also multimedia security has become an important concern in the world of internet technology. These factors indicates the need for various image compression and security techniques. This paper focuses on compression scheme which makes use of the sensitivity of the Human Visual System. A robust watermarking method is also incorporated to add copyright protection to the image. The compression technique is optimized perceptually by making use of a Contrast Sensitivity Function (CSF). The technique is based on a wavelet transform technique known as Embedded Zerotree Wavelet (EZW) along with CSF quantization. A band average of CSF value is calculated for each subband which gives the quantization value for the transformed coefficients of that subband. The performance metric used are PSNR, CR, SSIM. Results shows that compression ratio is increased for the proposed method with a comparable PSNR and SSIM. Result is also evaluated based on subjective quality.