US 5,293,434 A · Technique for use in a transform coder for imparting robustness to compressed image data through use of global block transformations

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.

Claims12

Dependent claims

Apparatus for imparting robustness to image data against localized data loss comprising:

a first transformer, responsive to an incoming matrix of pixel values representing an image, for globally transforming said matrix of pixel values through a block transformation so as to produce a plurality of blocks of transformed pixel values such that each transformed pixel value in each of said blocks of transformed pixel values is a pre-defined combination of all the pixel values in said incoming matrix;
a second transformer for transforming each one of the blocks of transformed pixel values into a corresponding one of a plurality of blocks of transform coefficients;
a quantizer for quantizing each one of said plurality of blocks of transform coefficients to yield a corresponding one of a plurality of blocks of quantized transform coefficients;
a coder for compressively coding said plurality of blocks of quantized transform coefficients into corresponding symbols;
and
means for applying said symbols in a pre-defined sequence to a channel;
and
wherein as a result of globally transforming said matrix of pixel values an image represented by said symbols possesses increased robustness against localized data loss occasioned by a channel imperfection.

5 more elements

Apparatus for imparting robustness to image data against localized data loss comprising:

a segmenter for segmenting an incoming matrix of pixel values representing an image into identically sized blocks of pixel values;
a first transformer for transforming each one of the blocks of pixel values into a corresponding one of a plurality of blocks of transform coefficients;
a quantizer for quantizing the coefficients in each one of said blocks of transform coefficients to yield a corresponding one of a plurality of blocks of quantized transform coefficients;
a second transformer for globally transforming all of said blocks of quantized transform coefficients through a block transformation into transformed data matrices such that each transformed data value in each of said transformed data matrices is a pre-defined combination of all the quantized transform coefficients in all of said blocks of quantized transform coefficients;
a coder for compressively coding said transformed data matrices into corresponding symbols;
and
means for applying said symbols in a pre-defined sequence to a channel;
and
wherein as a result of globally transforming all of said blocks of quantized transform coefficients an image represented by said symbols possesses increased robustness against localized data loss occasioned by a channel imperfection.

6 more elements

Dependencies are inferred from the claim text.

Technique for use in a transform coder for imparting robustness to compressed image data through use of global block transformations

Life of this patent

Technique for use in a transform coder for imparting robustness to compressed image data through use of global block transformations

Life of this patent

Abstract

Claims12