Christopher Michael Vogt

US Patent:

20060257034, Nov 16, 2006

Filed:

May 11, 2005

Appl. No.:

11/128125

Inventors:

Walter Gish - Oak Park CA, US
Christopher Vogt - Omaha NE, US

International Classification:

G06K 9/36
G06K 9/00

US Classification:

382239000, 382251000

Abstract:

The quantization parameter QP is well-known in digital video compression as an indication of picture quality. Digital symbols representing a moving image are quantized with a quantizing step that is a function QSof the quantization parameter QP, which function QShas been normalized to the most significant bit of the bit depth of the digital symbols. As a result, the effect of a given QP is essentially independent of bit depth—a particular QP value has a standard effect on image quality, regardless of bit depth. The invention is useful, for example, in encoding and decoding at different bit depths, to generate compatible, bitstreams having different bit depths, and to allow different bit depths for different components of a video signal by compressing each with the same fidelity (i.e., the same QP).