'\" te
.TH tiffdither 1 "26 Mar 2004" "SunOS 5.11" "User Commands"
.SH "NAME"
tiffdither \- convert a grayscale image to bilevel using dithering
.SH "SYNOPSIS"
.PP
\fBtiffdither\fR [\fB\fIoptions\fR\fR] \fB\fIinput\&.tif\fR\fR \fB\fIoutput\&.tif\fR\fR
.SH "DESCRIPTION"
.PP
\fBtiffdither\fR converts a single-channel 8-bit grayscale image
to a bilevel image using Floyd-Steinberg error propagation with thresholding\&.
.SH "OPTIONS"
.PP
The following options are supported:
.sp
.ne 2
.mk
\fB-\fBc\fR\fR
.in +16n
.rt
Specify a compression
scheme to use when writing image data:
.sp
.sp
.ne 2
.mk
\fB-\fBc g3\fR\fR
.in +24n
.rt
CCITT Group
3 compression algorithm\&.
.sp
.sp 2
.in -24n
.sp
.ne 2
.mk
\fB-\fBc g4\fR\fR
.in +24n
.rt
CCITT Group
4 compression algorithm\&.
.sp
.sp 1
.in -24n
.sp
.ne 2
.mk
\fB-\fBc lzw\fR\fR
.in +24n
.rt
Lempel-Ziv
and Welch algorithm\&.
.sp
.sp 1
.in -24n
.sp
.ne 2
.mk
\fB-\fBc none\fR\fR
.in +24n
.rt
No compression\&.
.sp
.sp 1
.in -24n
.sp
.ne 2
.mk
\fB-\fBc packbits\fR\fR
.in +24n
.rt
PackBits
compression algorithm\&.
.sp
.sp 1
.in -24n
.sp
.ne 2
.mk
\fB-\fBc zip\fR\fR
.in +24n
.rt
Deflate compression
algorithm\&.
.sp
.sp 1
.in -24n
By default, \fBtiffdither\fR compresses data
according to the value of the Compression tag found in the source file\&.
.sp
.sp 0
.in -16n
.sp
.ne 2
.mk
\fB-\fBf\fR\fR
.in +16n
.rt
Specify the bit
fill order to use to write output data\&. By default, \fBtiffdither\fR
creates a new file with the same fill order as the original\&. Specify -\fBf lsb2msb\fR to force data to be written with the FillOrder tag set
to LSB2MSB\&. Specify -\fBf msb2lsb\fR to force data to be written
with the FillOrder tag set to MSB2LSB\&.
.sp
.sp 1
.in -16n
.sp
.ne 2
.mk
\fB-\fBt\fR\fR
.in +16n
.rt
Set the threshold
value for dithering\&. By default, the threshold value is 128\&.
.sp
.sp 1
.in -16n
.SH "OPERANDS"
.PP
The following operands are supported:
.sp
.ne 2
.mk
\fB\fB\fIinput\&.tif\fR\fR\fR
.in +16n
.rt
The name of the input file\&.
.sp
.sp 1
.in -16n
.sp
.ne 2
.mk
\fB\fB\fIoutput\&.tif\fR\fR\fR
.in +16n
.rt
The name of the output file\&.
.sp
.sp 1
.in -16n
.SH "EXTENDED DESCRIPTION"
.PP
The CCITT Group 3 and Group 4 compression algorithms can only be used
with bilevel data\&.
.PP
Group 3 compression can be specified together with several T\&.4-specific
options:
.sp
.ne 2
.mk
\fB\fB1d\fR\fR
.in +24n
.rt
1-dimensional encoding
.sp
.sp 1
.in -24n
.sp
.ne 2
.mk
\fB\fB2d\fR\fR
.in +24n
.rt
2-dimensional encoding
.sp
.sp 1
.in -24n
.sp
.ne 2
.mk
\fB\fBfill\fR\fR
.in +24n
.rt
Force each encoded scanline to be zero-filled so that the terminating EOL
code lies on a byte boundary\&.
.sp
.sp 1
.in -24n
.PP
Group 3-specific options are specified by appending a
colon-separated list to the \fBg3\fR option\&. For
example, specify -\fBc\fR \fBg3:2d:fill\fR
to get 2D-encoded data with byte-aligned EOL codes\&.
.PP
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\&.
.PP
LZW-specific options are specified by appending a colon-separated list
to the \fBlzw\fR option\&. For example, specify -\fBc\fR \fBlzw:2\fR for LZW compression with horizontal
differencing\&.
.SH "ATTRIBUTES"
.PP
See \fBattributes\fR(5)
for descriptions of the following attributes:
.sp
.TS
tab() allbox;
cw(2.750000i)| cw(2.750000i)
lw(2.750000i)| lw(2.750000i).
ATTRIBUTE TYPEATTRIBUTE VALUE
Availabilityimage/library/libtiff
Interface stabilityUncommitted
.TE
.sp
.SH "SEE ALSO"
.PP
\fBpal2rgb\fR(1),
\fBfax2tiff\fR(1),
\fBtiffinfo\fR(1),
\fBtiffcp\fR(1),
\fBtiff2bw\fR(1),
\fBlibtiff\fR(3)
.SH "NOTES"
.PP
Updated by Breda McColgan, Sun Microsystems Inc\&., 2004\&.
...\" created by instant / solbook-to-man, Thu 20 Mar 2014, 02:30
...\" LSARC 2003/085 libtiff, libjpeg, and libpng