tiffdither(1)
| TIFFDITHER(1) | LibTIFF | TIFFDITHER(1) |
NAME
tiffdither - convert a greyscale TIFF image to bilevel using dithering
SYNOPSIS
tiffdither [ options ] input.tif output.tif
DESCRIPTION
tiffdither converts a single channel 8-bit greyscale image to a bilevel image using Floyd-Steinberg error propagation with thresholding.
OPTIONS
- -c compress
- Specify the compression to use for data written to the output file:
Compression Description none no compression packbits PackBits compression lzw Lempel-Ziv & Welch compression zip Deflate compression g3 CCITT Group 3 (T.4) compression g4 for CCITT Group 4 (T.6) compression By default tiffdither will compress data according to the value of the Compression tag found in the source file.
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 for 1-dimensional encoding, 2d for 2-dimensional encoding, and 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 predictor value. 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.
- -f
- Specify the bit fill order to use in writing output data. By default, tiffdither will create a new file with the same fill order as the original. Specifying -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.
- -r
- Make each strip have no more than the given number of rows.
- -t
- Set the threshold value for dithering. By default the threshold value is 128.
NOTES
The dither algorithm is taken from the tiffmedian program (written by Paul Heckbert).
SEE ALSO
pal2rgb <> (1), fax2tiff <> (1), tiffinfo <> (1), tiffcp <> (1), tiff2bw <> (3tiff)
Author
LibTIFF contributors
Copyright
1988-2025, LibTIFF contributors
| August 14, 2026 | 4.7 |