| 摘要 |
With the facsimile transmission of pictures the run run-lengths (plurality of successive picture elements of the same luminance value) are often transmitted in coded form to save transmission time and transmission bandwidth respectively. Herein the shortest run-length is often allocated to the shortest code word. In accordance with the invention every run length having the value 1 is either extended to the value 2 or suppressed and the shortest code word is then allocated in a corresponding manner to the run-length 2. As a result the total length of the transmitted code words for a document is considerably reduced. Extension is done such that one picture element is extended to the left to the detriment of the preceding run-length having the opposite luminance value provided this preceding runlength still contains thereafter at least two picture elements and that in the other case one picture element is extended to the right to the detriment of the next run-length provided the latter retains at least the value 2 and that otherwise the run-length having the value 1 is suppressed. It is true that the resolution is slightly reduced, however only for the very thin lines which is fully acceptable and in many cases hardly noticeable.. |
