发明名称 |
System und Verfahren zur Bildkodierung und zugehöriges Rechnerprogrammprodukt |
摘要 |
A method for image compression of a set of image data (I) includes operating a quantization operation (20; 150; 230) on the image data (I), said quantization operation (20; 150; 230) including controlling a compression factor by applying a scaled quantization level ( ), obtained by multiplying a first quantization level (Q) by a gain factor (G; Gs; Gi), the gain factor (G; Gs; Gi) being updated (100; 1000; 110; 300) as a function of a bit per pixel value (bpp) of a compressed image (O). The update operation (1000; 110; 300) includes an iterative procedure (110) comprising at least one iteration step (Eq. 6; Eq. 7) that provides for updating a current gain factor (G n+1 ) as a function of a previous gain (G n ) used for performing a previous compression step and as a function of a ratio (G n ) of the bit per pixel value (bpp) of the compressed image (O) at the previous compression step to a target bit per pixel value (T). Preferred application is in Joint Photographic Experts Group (JPEG) and digital still cameras. |
申请公布号 |
DE602004010509(D1) |
申请公布日期 |
2008.01.17 |
申请号 |
DE20046010509T |
申请日期 |
2004.09.03 |
申请人 |
STMICROELECTRONICS S.R.L., AGRATE BRIANZA;STMICROELECTRONICS LTD. |
发明人 |
SMITH, STEWART G.;BRUNA, ARCANGELO RANIERI;VELLA, FILIPPO |
分类号 |
G06T9/00 |
主分类号 |
G06T9/00 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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