Image quality prediction apparatus and method, and image quality control apparatus and method
US5991458A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 15, 1997 |
| Grant date | Nov 23, 1999 |
| Priority date | — |
| Expiry date | Aug 15, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/146
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An image quality control apparatus having an image divider, a converter, an image analyzer, an image output property circuit, a quantization method selector, a quantizer and a coder. The image divider divides an input image into a plurality of divided images including a predetermined number of picture elements. The converter converts the divided images into converted coefficients. Then, the image analyzer determines a property of the divided images which is output by the image output property output circuit. A quantization selector selects a quantization method in response to the divided image property that was found by the image analyzer and the image output property output circuit. The quantizer quantizes the conversion coefficients found by the converter in accordance with the quantization methods selected by the quantization selector. A coder then codes the conversion coefficients quantized by the quantizer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.