tiffdither(1) User Commands tiffdither(1)
NAME
tiffdither - convert a grayscale image to bilevel using dithering
SYNOPSIS
tiffdither [options] input.tif output.tif
DESCRIPTION
tiffdither 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 algorithm.
-c g4 CCITT Group 4 compression algorithm.
-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 |SUNWTiff |
+-----------------------------+-----------------------------+
|Interface stability |External |
+-----------------------------+-----------------------------+
SEE ALSO
pal2rgb(1), fax2tiff(1), tiffinfo(1), tiffcp(1), tiff2bw(1), libtiff(3)
NOTES
Updated by Breda McColgan, Sun Microsystems Inc., 2004.
SunOS 5.10 26 Mar 2004 tiffdither(1)