Adaptive block transform image coding method and apparatus
First Claim
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1. A transmitter for compressing and transmitting a digital image over a limited bandwidth communication channel, comprising:
- a. means for performing a two-dimensional spatial frequency block transformation on the digital image to produce blocks of transform coefficients;
b. means for quantizing the transform coefficients in accordance with a model of the visibility of quantization error in the presence of image detail;
c. means for encoding the quantized transformation coefficients with a minimum redundancy code; and
d. means for transmitting the encoded transform coefficients.
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Abstract
In a method and apparatus for transmitting a digital image over a limited bandwidth communication channel, an image is block transformed to produce blocks of transform coefficients; the transform coefficients are quantized in accordance with a model of the visibility of quantization error in the presence of image detail; the quantized coefficients are encoded with a minimum redundancy code; and the coded, quantized transform coefficients are transmitted.
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Citations
14 Claims
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1. A transmitter for compressing and transmitting a digital image over a limited bandwidth communication channel, comprising:
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a. means for performing a two-dimensional spatial frequency block transformation on the digital image to produce blocks of transform coefficients; b. means for quantizing the transform coefficients in accordance with a model of the visibility of quantization error in the presence of image detail; c. means for encoding the quantized transformation coefficients with a minimum redundancy code; and d. means for transmitting the encoded transform coefficients. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A method for compressing a digital image for transmission over a limited bandwidth communication channel, comprising the steps of:
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a. performing a two-dimensional spatial frequency block transformation on the digital image to produce blocks of transform coefficients; b. quantizing the transform coefficients in accordance with a model of the visibility of quantization error in the presence of image detail; and c. encoding the quantized transformation coefficients employing a minimum redundancy code. - View Dependent Claims (9, 10, 11, 12, 13, 14)
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Specification