US 7,352,903 B2 · Methods and apparatus for implementing JPEG 2000 encoding operations

Abstract

Improved methods and apparatus for implementing JPEG 2000 MQ encoding operations are described. The following features of the invention may be used alone or in combination to implement JPEG 2000's coefficient bit modeling 1) Lists of coefficients to be processed in one or more subsequent coding passes are generated as coefficients are processed. The list is allows processing in the subsequent coding pass to be limited to coefficients on the list; and 2) Generation, updating and use of a neighborhood descriptor value table that stores a neighborhood descriptor value for each coefficient of a block being processed. The neighborhood descriptor values provide information about the state of the coefficient and its adjacent neighbors. Neighborhood descriptor values are used to access a lookup table that provides one or more context values and/or sign value to be used in MQ encoding. The neighborhood descriptor value corresponding to a coefficient and the neighborhood descriptor values corresponding to coefficients adjacent the coefficient are updated when the coefficient becomes significant, e.g., a 1 is first encountered in the coefficient.

Claims21

Dependent claims

A method of performing an MQ encoding operation on at least one coefficient in a block of coefficients representing at least a portion of an image, said at least one coefficient being a quantized coefficient value including at least one coefficient bit value and a sign bit, the method comprising:

storing a neighborhood descriptor value in a memory for said at least one coefficient value, said neighborhood descriptor value being stored in a set of neighborhood descriptor values, each coefficient value in said block having a separate corresponding neighborhood descriptor value in said set of neighborhood descriptor values;
performing a look up operation using the neighborhood descriptor value corresponding to said at least one coefficient as an index into a neighborhood descriptor value information table to determine from said neighborhood descriptor information table, an MQ coder context state associated with the neighborhood descriptor value corresponding to said at least one coefficient, said MQ coder context state being a context state used as a control input when coding at least one of:
said at least one coefficient bit value of said at least one coefficient and said sign bit of said at least one coefficient;
and
using said determined context state to perform an MQ coding operation on at least one of said at least one coefficient bit value and said sign bit of said at least one coefficient.

2 more elements

A system for performing JPEG-2000 MQ encoding operations on at least one coefficient in a block of coefficients representing at least a portion of an image, said at least one coefficient being a quantized coefficient value including at least one coefficient bit value and a sign bit, the system comprising:

a memory including a set of neighborhood descriptor values, said set including one neighborhood descriptor value for each coefficient in said block of coefficients;
a neighborhood descriptor value information lookup table including an entry associating at least one encoding context value with a neighborhood descriptor value;
means for performing a look up operation using the neighborhood descriptor value corresponding to said at least one coefficient as an index into said neighborhood descriptor value information lookup table to determine from said neighborhood descriptor information lookup table, an MQ coder context state associated with the neighborhood descriptor value corresponding to said at least one coefficient, said MQ coder context state being a context state used as a control input when coding at least one of:
said at least one coefficient bit value of said at least one coefficient and said sign bit of said at least one coefficient;
and
means for supplying the determined context value to an MQ coder for performing an MQ coding operation on at least one of said at least one coefficient bit value and said sign bit of said at least one coefficient.

3 more elements

Dependencies are inferred from the claim text.

Methods and apparatus for implementing JPEG 2000 encoding operations

Life of this patent

Methods and apparatus for implementing JPEG 2000 encoding operations

Life of this patent

Abstract

Claims21