A novel still image error concealment using fragile watermarking in wireless image transmission and packet-switched networks

Abstract

Images transmitted over unreliable channels are highly prone to errors. Produces distortion in transmitted images is usually repaired using post processing techniques called error concealment. Error concealment techniques provide a simple framework to compensate the produced distortions without incurring additional delays and wasting bandwidth resources which are crucial for real-time applications over networks with limited resources. Utilizing data hiding techniques is a suitable approach to overcome these restrictions. In this paper, we propose a new error concealment method for covering up the high packet losses of an original image after its transmission through an error-prone channel. Our proposed technique utilizes discrete wavelet transform (DWT) to produce a lower resolution copy of the original image. Then we embed some of DCT coefficients of this downsized replica of the original image into the original image in spatial (pixel) domain inside macroblocks (MBs) as a watermark. Wrong extracted watermark is detected immediately which is one of the distinguished characteristics of this algorithm. This technique can be implemented for error-prone channels to combat degradations due to packets loss in a backward-compatible scheme.