Technique for use in a transform coder for imparting robustness to

Abstract

A technique for use in, illustratively, a transform coder for imparting robustness against burst (or similar) errors to data patterns, such as illustratively two-dimensional image data, that exhibit local redundancy. Robustness is provided, in the case of images, by passing localized (blocked) image data, i.e. either pixel values or transformed, illustratively discrete cosine transform (DCT), image coefficient values therefor, through a global block transform, such as a global block Hadamard transform, prior to compression coding in order to produce 'holographic-like' compressed data for subsequent transmission and/or storage. Specifically, globally transforming an image in this fashion effectively spreads (diffuses) the image data in each block of pixels in that image or in the transform coefficients therefor in a regularly ordered pre-defined global manner throughout the entire image to create what is, in effect, intentionally 'smeared' image data. By subjecting the 'smeared' image data upon de-compression to an inverse global block transformation, such as an inverse global block Hadamard transformation, then, even if a portion of the 'smeared' data for an image is obliterated during transmission or playback, the entire image can still be advantageously reconstituted, though at a somewhat degraded quality, from the remaining 'smeared' data.