Wavelet image coder using trellis-coded quantization
AssigneeMotorola, Inc.
InventorGlen Patrick Abousleman
Life of this patent
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Abstract
A system (8) for digital processing of optical image data includes a wavelet decomposition unit (12) for decomposing an input image (10) into a plurality of frequency subbands. Each subband is then converted to a frequency domain representation, phase scrambled, and then converted back into a time domain representation in a phase scrambling unit (14). The subbands are then subject to trellis coded quantization (TCQ) in a trellis coded quantization encoding unit (16, 40) before being transmitted into a channel (28). In one embodiment, fixed rate trellis coded quantization (FRTCQ) is used in a communications system having a relatively noiseless channel.
Claims19
An image coder for use in encoding an image for transmission over a channel, comprising:
- an input image source for providing an image to be encoded;
- a wavelet decomposition unit for dividing said image into a plurality of two dimensional frequency subbands, each of said plurality of two dimensional frequency subbands having X rows and Y columns wherein X and Y vary with each of the subbands;
- a phase scrambling unit for generating phase scrambled frequency subbands by modifying a phase component of each of said plurality of two dimensional frequency subbands using a one-dimension m-sequence truncated to a (X) times (Y) length;
- and
- a fixed rate trellis coded quantization (FRTCQ) unit for performing FRTCQ on said phase scrambled frequency subbands.
A communications system for delivering an image from a first location to a second location, comprising:
- a transmitter at said first location for creating a transmit signal including a first image, said transmitter including an image coder comprising:
- a wavelet decomposition unit for dividing said first image into a plurality of two dimensional frequency subbands, each of said plurality of two dimensional frequency subbands having X rows and Y columns wherein X and Y vary with each of the subbands;
- a phase scrambling unit for generating phase scrambled frequency subbands by modifying a phase component of each of said two dimensional frequency subbands using a one-dimension m-sequence truncated to a (X) times (Y) length;
- and
- a fixed rate trellis coded quantization (FRTCQ) unit for performing FRTCQ on said phase scrambled frequency subbands;
- a receiver at said second location for receiving said transmit signal and for processing said transmit signal to extract said first image;
- and
- a channel for carrying said transmit signal from said transmitter to said receiver wherein said channel approximates a noiseless channel.
Dependencies are inferred from the claim text.