Josephine D Smith

US Patent:

20100092096, Apr 15, 2010

Filed:

Oct 9, 2008

Appl. No.:

12/248217

Inventors:

Edgar Bernal - Webster NY, US
Robert Paul Loce - Webster NY, US
Josephine Smith - Bloomfield NY, US

Assignee:

Xerox Corporation - Norwalk CT

International Classification:

G06K 9/36

US Classification:

382233

Abstract:

In accordance with the present disclosure, there is provided a method for performing streak compensation on compressed digital image data. The method comprises generating the compressed digital image data using a compression method employing a discrete cosine transform (DCT) and recovering a zero frequency component (DC coefficient) of the discrete cosine transform (DCT) for each of a plurality of compressed unit blocks of image data wherein each unit block includes N pixel columns. The method further comprises applying spatially varying compensating tone reproduction curves (TRC) to the DC coefficients of each of the plurality of unit blocks on a block-column basis wherein each block-column receives compensation from a given TRC, re-compressing the compensated image data, and subsequently decompressing all of the compensated units to produce decompressed compensated image data.