gif2epsn.doc

GIF87a的压缩

			Gif2Epsn
			--------

Program to dump images saved as GIF files on Epson type printers.


Usage:
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Usage: Gif2Epsn [-d DitherSize] [-t BWThreshold] [-m Mapping] [-i] [-n]
						[-p PrinterName] [-h] GifFile

If no GifFile is given, Gif2Epsn will try to read stdin for GIF file.


Memory required:
----------------

Screen.


Options:
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1. [-d DitherSize] : Sets size of dithering matrix, where DitherSize can be
   2,3 or 4 only (for 2x2, 3x3 and 4x4 dithering matrices). Default is 2.
   Note image will be displayed in this mode only if Mapping (see -m)
   selected this mode.
2. [-t BWThreshold] : Sets threshold level for B&W mapping in percent.
   This threshold level is used in the different mappings as selected via -m.
   Default is 19%.
3. [-m mapping] : Select method to map colors to B&W. Mapping can be:
   0 : Every none background color is considered foreground (white color but
       is drawn as black by printer, unless -i is specified).
   1 : 0.3 * RED + 0.59 * GREEN + 0.11 * YELLOW > BWThreshold is considered
       white color.
   2 : Colors are mapped as in 1, and use dithering of size as defined using
       -d option. BWthreshold is used here as scaler.
   Default is option 0.
4. [-i] : Invert the image, i.e. black -> white, white -> black.
5. [-n] : Nicer image. Uses double density feature of Epson printer, to make
	  nicer result. This takes more time (and kill your ink cartridge
	  faster...) but results are usually better.
6. [-p PrinterName] : by default output is sent to LPT1:. If  other device
	  or disk file is required, they should be specified here. Note
	  devices are NOT specifed with colon, so to use LPT2: instead:
	  '-p lpt2' is required. Nothing is sent to stdout. If a disk file is
	  created: '-p file1.eps' then it can be printed any time by the
	  copy command: 'copy file1.eps prn:/b'. Note the /b for binary copy.
7. [-h] : print one command line help, similar to Usage above.

Notes:
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  The output has aspect ratio of 1, so square image, will be square in its
hardcopy as well.
  The widest image can be printed is 640 pixels, on 8 inches paper. You
probably will need to flip wider images, if height is less than that:
'gifflip -r x29.gif | gif2epsn'. Wider images will be clipped.