157 lines
5.0 KiB
Groff
157 lines
5.0 KiB
Groff
.TH IM_TIFF 3 "6 June 1994"
|
|
.SH NAME
|
|
im_tiff2vips, im_tiff2vips_header, im_tiff2vips \- convert TIFF images to and from VIPS format
|
|
.SH SYNOPSIS
|
|
#include <vips/vips.h>
|
|
|
|
int im_tiff2vips( const char *filename, IMAGE *out )
|
|
|
|
int im_tiff2vips_header( const char *filename, IMAGE *out )
|
|
|
|
int im_vips2tiff( IMAGE *in, const char *filename )
|
|
|
|
.SH DESCRIPTION
|
|
.B im_tiff2vips(3)
|
|
reads the tiff image in filename, and writes the image out
|
|
in VIPS format. It is a full baseline TIFF 6 reader, with extensions for
|
|
tiled images, multipage images, LAB colour space, pyramidal images and
|
|
JPEG compression.
|
|
|
|
You can embed options in the filename. They have the form:
|
|
|
|
filename.tif:<page-number>
|
|
|
|
.B page-number
|
|
lets you read a particular page out of a multipage TIFF file. For
|
|
example:
|
|
|
|
"fred.tif:12"
|
|
|
|
will read page 12 (numbering from page zero) from the TIFF image.
|
|
|
|
Use
|
|
.B im_istifftiled(3)
|
|
and
|
|
.B im_istiffpyramid(3)
|
|
to find the TIFF image type before calling.
|
|
|
|
.B im_tiff2vips_header(3)
|
|
reads just the header information from the TIFF file. You can't read any
|
|
pixels!
|
|
|
|
.B im_vips2tiff(3)
|
|
reads the image in and writes a TIFF file to the specified
|
|
filename. The filename may include an optional mode string, following a ':'
|
|
character. For example, "fred.tif" would write a default TIFF file (flat,
|
|
strips, no compression). Writing to "fred.tif:deflate,tile:64x64" would write a
|
|
ZIP-coded image, split into 64 by 64 pixel tiles.
|
|
|
|
The mode string has the following syntax:
|
|
|
|
<compression>,<layout>,<multi-res>,<format>,<resolution>,<icc>
|
|
|
|
where <compression> is one of:
|
|
|
|
"none" - no compression
|
|
"jpeg" - JPEG compression
|
|
"deflate" - ZIP (deflate) compression
|
|
"packbits" - TIFF packbits compression
|
|
"ccittfax4" - CCITT Group 4 fax encoding
|
|
"lzw" - Lempel-Ziv compression
|
|
|
|
"jpeg" compression can be followed by a ":" character and a JPEG quality
|
|
level; "lzw" and "deflate" can be followed by a ":" and predictor value. The
|
|
default compression type is "none", the default JPEG quality factor is 75.
|
|
|
|
Predictor is not set by default. There are three predictor values recognised
|
|
at the moment (2007, July): 1 is no prediction, 2 is a horizontal differencing
|
|
and 3 is a floating point predictor. Refer to the libtiff specifications for
|
|
further discussion of various predictors. In short, predictor helps to better
|
|
compress image, especially in case of digital photos or scanned images and bit
|
|
depths > 8. Try it to find whether it works for your images.
|
|
|
|
JPEG compression is a good lossy compressor for photographs, packbits is good
|
|
for 1-bit images, and deflate is the best lossless compression TIFF can do.
|
|
LZW has patent problems and is no longer recommended.
|
|
|
|
<layout> is one of:
|
|
|
|
"strip" - strip layout
|
|
"tile" - tiled layout
|
|
|
|
"tile" layout can be followed by a ":" character and the horizontal and
|
|
vertical tile size, separated by a "x" character. The default layout is
|
|
"strip", and the default tile size is 128 by 128 pixels.
|
|
|
|
<multi-res> is one of:
|
|
|
|
"flat" - single image
|
|
"pyramid" - many images arranged in a pyramid
|
|
|
|
The default multi-res mode is "flat".
|
|
|
|
<format> is one of:
|
|
|
|
"manybit" - don't bit-reduce images
|
|
"onebit" - one band 8 bit images are saved as 1 bit
|
|
|
|
The default format is "multibit".
|
|
|
|
<resolution> is one of:
|
|
|
|
"res_cm" - output resolution unit is pixels per centimetre
|
|
"res_inch" - output resolution unit is pixels per inch
|
|
|
|
The default resolution unit is taken from the header field "resolution-unit"
|
|
(IM_META_RESOLUTION_UNIT in C). If this field is not set, then VIPS defaults
|
|
to cm.
|
|
|
|
This may be overridden by the <resolution> option. The unit can optionally
|
|
be followed by a ":" character and the horizontal and vertical resolution,
|
|
separated by a "x" character. You can have a single number with no "x" and
|
|
set the horizontal and vertical resolutions together. The default unit is
|
|
cm, and the default resolution is taken from the VIPS header.
|
|
|
|
<icc> is the filename of an ICC profile to embed in the TIFF file
|
|
|
|
The TIFF reader and writer are based on Sam Leffler's TIFF library, and the IJG
|
|
JPEG coder.
|
|
|
|
.SH EXAMPLES
|
|
|
|
The call:
|
|
|
|
im_vips2tiff fred.v fred.tif
|
|
|
|
Writes a striped, uncompressed TIFF image. Almost anything should be able to
|
|
read this.
|
|
|
|
im_vips2tiff fred.v fred.tif:jpeg,tile,pyramid
|
|
|
|
Writes a tiled JPEG pyramid image. Although VIPS tries to follow the TIFF
|
|
specification carefully, you may have trouble reading this on any system other
|
|
than VIPS.
|
|
|
|
im_vips2tiff fred.v fred.tif:jpeg:25,tile:64x64
|
|
|
|
Writes a highly compressed JPEG image, with a tile size of 64 by 64 pixels.
|
|
|
|
im_vips2tiff fred.v fred.tif:,tile
|
|
|
|
Writes an uncompressed tiled image.
|
|
|
|
im_vips2tiff fred.v fred.tif:packbits,tile,,onebit
|
|
|
|
Writes a tiled one bit TIFF image (provided fred.v is a one band 8 bit image)
|
|
compressed with packbits.
|
|
|
|
im_vips2tiff fred.v fred.tif:,,,,res_inch:300
|
|
|
|
Writes fred.v as a tiff file, with the resolution in the tiff header set to
|
|
300 dpi.
|
|
|
|
.SH SEE ALSO
|
|
im_istiff(3), im_istifftiled(3), im_istiffpyramid(3)
|
|
.SH COPYRIGHT
|
|
Hey, you want this? You have it!
|