| 摘要 |
<p>The method and the device are used in the systems for transmitting photo- and TV-patterns across digital networks of the ISDN, ATM, Internet, satellite and cable connection canal types, etc. According to the method based on the pattern decomposition by inverse differential pyramid, the pattern is approximated by polynomial function the coefficients of which are determined by regression analysis, or by a pattern produced by inverse orthogonal conversion of the filtered transformant of the input pattern after preserving in it a small number of low frequency coefficients. These coefficients form the "zero" level (peak) of the pyramid. For forming its next level from the input pattern its approximation is subtracted, determined by the coefficients of the "zero" level. The "zero" difference pattern produced is divided in four equal in form and size sub-patterns and for each of them analogous operations are applied for finding their respective approximating patterns. For loss-free (reversible) compression 1/4 of the coefficient in the adjacent sub-patterns are reduced based on their relations, and entropy encoding is applied on the remaining ones. To increase the compression coefficient encoding without visual losses is applied without bilateral "trimming" from top and bottom of the low information levels of the pyramid and quantizing the coefficients in the remaining levels before their entropy encoding. The device allows recursive calculation of the decomposition without any use of decimation and interpolation. 2 claims, 2 figures</p> |
