Multiple description coding of images using phase scrambling

We discuss phase scrambling which spreads the information in each pixel of an image among virtually all the pixels of the resulting scrambled image. This property can be exploited in multiple description coding of images where the loss of one or many descriptions is a common case. We employ phase scrambling, as a form of all-pass filtering to mix the information of each pixel with all the pixels of the image, followed by decomposing the scrambled image into multiple descriptions. Our experiments show that this technique is competitive with other proposed methods, such as lapped orthogonal transforms. Phase scrambling does not produce localized visual artifacts, such as ringing and blocking effects, and does not require complex post-filtering to yield acceptable reconstruction quality. Another advantage of phase scrambling is that the scrambling can be implemented in hardware and performed in real time.