Image signal compression apparatus and method using variable length encoding
US5440404A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 13, 1994 |
| Grant date | Aug 8, 1995 |
| Priority date | — |
| Expiry date | Jan 13, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/91
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A transform unit obtains a discrete cosine coefficient by processing an image signal in a discrete cosine transform fashion per unit of a predetermined data amount. A memory includes therein a plurality of quantization tables corresponding to quantization accuracies different from each other, and a memory includes therein a variable length coding table. A quantization unit quantizes the discrete cosine coefficient with reference to a selected one of the plurality of quantization tables. An encoding unit obtains encoded data by processing the quantized discrete cosine coefficient in a variable length coding fashion. A code amount adding unit obtains total amount data indicative of a total amount of the encoded data corresponding to the predetermined data amount. The encoded data, the total amount data and table identification data corresponding to a selected one of the plurality of quantization tables are temporarily stored in an FIFO memory and these data are read out therefrom as a compression code in a predetermined order.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.