tiffdither(1) User Commands tiffdither(1)NAMEtiffdither - convert a grayscale image to bilevel using dithering
SYNOPSIStiffdither [options] input.tif output.tif
DESCRIPTIONtiffdither converts a single-channel 8-bit grayscale image to a bilevel
image using Floyd-Steinberg error propagation with thresholding.
OPTIONS
The following options are supported:
-c Specify a compression scheme to use when writing image
data:
-c g3 CCITT Group 3 compression algo‐
rithm.
-c g4 CCITT Group 4 compression algo‐
rithm.
-c lzw Lempel-Ziv and Welch algorithm.
-c none No compression.
-c packbits PackBits compression algorithm.
-c zip Deflate compression algorithm.
By default, tiffdither compresses data according to the
value of the Compression tag found in the source file.
-f Specify the bit fill order to use to write output data.
By default, tiffdither creates a new file with the same
fill order as the original. Specify -f lsb2msb to force
data to be written with the FillOrder tag set to
LSB2MSB. Specify -f msb2lsb to force data to be written
with the FillOrder tag set to MSB2LSB.
-t Set the threshold value for dithering. By default, the
threshold value is 128.
OPERANDS
The following operands are supported:
input.tif The name of the input file.
output.tif The name of the output file.
EXTENDED DESCRIPTION
The CCITT Group 3 and Group 4 compression algorithms can only be used
with bilevel data.
Group 3 compression can be specified together with several T.4-specific
options:
1d 1-dimensional encoding
2d 2-dimensional encoding
fill 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 colon-separated
list to the g3 option. For example, specify -c g3:2d:fill to get 2D-
encoded data with byte-aligned EOL codes.
LZW compression can be specified together with a predictor value. A
predictor value of 2 causes each scanline of the output image to
undergo horizontal differencing before being encoded. A predictor value
of 1 forces each scanline to be encoded without differencing.
LZW-specific options are specified by appending a colon-separated list
to the lzw option. For example, specify -c lzw:2 for LZW compression
with horizontal differencing.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
┌─────────────────────────────┬─────────────────────────────┐
│ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
├─────────────────────────────┼─────────────────────────────┤
│Availability │image/library/libtiff │
├─────────────────────────────┼─────────────────────────────┤
│Interface stability │Uncommitted │
└─────────────────────────────┴─────────────────────────────┘
SEE ALSOpal2rgb(1), fax2tiff(1), tiffinfo(1), tiffcp(1), tiff2bw(1), libtiff(3)NOTES
Updated by Breda McColgan, Sun Microsystems Inc., 2004.
SunOS 5.11 26 Mar 2004 tiffdither(1)
