Adaptive block transform image coding method and apparatus
AssigneeEastman Kodak Company
InventorsScott J. Daly, Cheng-Tie Chen, Majid Rabbani
Life of this patent
Estimating the term…
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.
Claims14
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.
A method for compressing a digital image for transmission over a limited bandwidth communication channel, comprising the steps of:
- 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.
Dependencies are inferred from the claim text.