tiffdither - Unix, Linux Command
tiffdither - convert a greyscale image to bilevel using dithering
converts a single channel 8-bit greyscale image to a bilevel image
using Floyd-Steinberg error propagation with thresholding.
Specify the compression to use for data written to the output file:
none for no compression,
packbits for PackBits compression,
lzw for Lempel-Ziv & Welch compression,
zip for Deflate compression,
g3 for CCITT Group 3 (T.4) compression,
g4 for CCITT Group 4 (T.6) compression.
tiffdither will compress data according to the value of the
Compression tag found in the source file.
CCITT Group 3 and Group 4 compression algorithms can only
be used with bilevel data.
Group 3 compression can be specified together with several
1d for 1-dimensional encoding,
2d for 2-dimensional encoding,
fill to force each encoded scanline to be zero-filled so that the
terminating EOL code lies on a byte boundary.
Group 3-specific options are specified by appending a :-separated
list to the g3 option; e.g.
-c g3:2d:fill to get 2D-encoded data with byte-aligned EOL codes.
LZW compression can be specified together with a
A predictor value of 2 causes
each scanline of the output image to undergo horizontal
differencing before it is encoded; a value
of 1 forces each scanline to be encoded without differencing.
LZW-specific options are specified by appending a :-separated
list to the lzw option; e.g.
-c lzw:2 for
LZW compression with horizontal differencing.
Specify the bit fill order to use in writing output data.
tiffdither will create a new file with the same fill order as the original.
-f lsb2msb will force data to be written with the FillOrder tag set to
LSB2MSB , while
-f msb2lsb will force data to be written with the FillOrder tag set to
MSB2LSB . |
Set the threshold value for dithering.
By default the threshold value is 128.
The dither algorithm is taken from the
program (written by Paul Heckbert).
Libtiff library home page: