For that, first I had to understand the Graphics Formats.
I tried to explore them by drawing simple small Pictures using
PaintBrush or
somewhat. Then I saved the Pictures and analyzed them with a
HEX-Editor.
In case of the PCX and BMP Format I was quite successful, but
at the GIF
I failed miserably!
That's why I was forced to face the problem in the direct way.
Important clues could be found on the Web at
gif89a.doc.
But most difficult was the problem of LZW decoding, because it is
a part of the
GIF format, but not described there.
At last I found something in the "Data Compression Book".
The Results of my investigations are summarized in the Text Documents
GIF1_E.TXT - GIF Specification (11 kBytes)
GIF2_E.TXT - The LZW Decoder (7 kBytes)
GIF3_E.TXT - Program Examples (13 kBytes)
GIF4_E.TXT - Save as GIF (9 kBytes)
But Caution! I translated it in a "quick and dirty" way from German
and I am afraid
my English teacher would rotate in the grave reading it.
Questions, Suggestions, Bug Reports? Please send it to
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