Re: [apache-talk] Re: [apache-talk] ??????? ????????? ? ???????????? ???????.

["Khimenko Victor" <khim@xxxxxxxxxxxx>]

In <19991109201300.R3696@xxxxxxxxxxx> Eugene B. Berdnikov (berd@xxxxxxxxxxxxxx) wrote:
EB> On Tue, Nov 09, 1999 at 12:09:20PM +0300, Victor Wagner wrote:
>> Ну, во-первых, gif это не обязательно lzw.

EB>  Как это не lzw? Поясните, pls.

Почитаей документацию на libungif :-) Там объясняется -- как можно не нарушая
патента генерить "нечто", что не будет сжатием вообще (на самом деле будет
даже увеличение размера на 1/8) но будет корректо обрабатываться lzw'ным
unpacker'ом и давать в результате то, что было на входе...

EB> Cover Sheet for the GIF89a Specification

EB> [...]

EB> 22. Table Based Image Data.

EB>      a. Description. The image data for a table based image consists of a
EB>      sequence of sub-blocks, of size at most 255 bytes each, containing an
EB>      index into the active color table, for each pixel in the image.  Pixel
EB>      indices are in order of left to right and from top to bottom.  Each index
EB>      must be within the range of the size of the active color table, starting
EB>      at 0. The sequence of indices is encoded using the LZW Algorithm with
EB>      variable-length code, as described in Appendix F
EB>                                                         ^^^^^^^^^^^^^



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