Patent ID: 7218789

Claim:
A method for generating a first plurality of output data values by transforming a plurality of input data values using a computer, the first plurality of output data values approximating a second plurality of output data values, the second plurality of output data values generated by applying a linear transform to the plurality of input data values, the method comprising the step of: modifying at least one data value in the plurality of current input data values, each modified data value generated by applying a linear combination of unmodified values in the plurality of input data values to the at least one data value, the linear combination comprised of an integer generated in a reproducible manner, the integer being from one of a group consisting of a rounded integer and a converted integer; wherein the linear transform is a fixed finite-dimensional linear transform, and wherein the step of modifying the at least one data value in the plurality of current input data values comprises: successively sweeping through a plurality of bands of input data values in a first direction: successively adding to each band during each successive sweep in the first direction the linear combination of unmodified values in the plurality of input data values, the linear combination being a rounded linear combination of the plurality of input data values in preceding bands; successively sweeping through a plurality of bands in a second direction, the second direction being different than the first direction; successively adding to each band during each successive sweep in the second direction the linear combination of unmodified values in the plurality of input data values, the linear combination being a rounded linear combination of the plurality of input data values in preceding bands; and adding to one of the bands the linear combination of unmodified values in the plurality of input data values, the linear combination being a rounded linear combination of the plurality of input data values in all remaining bands.