Image-processing apparatus and method
US7583850B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 22, 2004 |
| Grant date | Sep 1, 2009 |
| Priority date | — |
| Expiry date | Jul 31, 2027 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T2201/0053
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A bit stream is decoded to generate first quantized DCT-coefficients. The first quantized DCT-coefficients are inversely quantized using a first quantization table, thereby generating DCT-coefficients. The resulting DCT-coefficients are quantized using a second quantization table, thereby generating second quantized DCT-coefficients. Elements in the second quantization table are smaller in value than those in the first quantization table. Predetermined additional information is embedded into the second quantized DCT-coefficients. The second quantized DCT-coefficients having the additional information embedded therein are encoded to produce a bit stream having the additional information embedded therein. The second quantization table is set to be smaller in value than the first quantization table.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.