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- General information - GIF utilities
- -----------------------------------
-
- Each of the utilities provided in 'util' directory perform some kind of
- filtering, generating new image, or dumping it to a device.
-
- Because they are not fast, a filter will print (in increasing) order the
- current input image line number, any time it needs to read the input, and
- will print output image line number (in decreasing order) any time it dumps
- out. Other utilities, that only read or write, will always print that half
- the same way (but in increasing order). This is true only for utilities
- that decodes the data. Utilities (like GifPos that only change positions)
- that copies the image as block of compressed data, will print nothing for
- two reasons: they can not idetify line number, and mainly as they are much
- faster.
-
- Some of the utilities requirs memory in the order of the whole screen, while
- others read one scan line at a time. Each utility DOC file, has entry called
- 'Memory Usage' which will be one of: Line (memory required is in the order
- of one scan line), Image (order of biggest image in GIF file), or Screen (order
- of GIF file screen). In all cases, a byte is allocated per pixel, so image of
- 320 by 200 pixels will requires ~64k bytes to hold.
-