| .TH IM_TIFF 3 "6 June 1994" |
| .SH NAME |
| im_tiff2vips, 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_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. |
| |
| .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_open(3) |
| .SH COPYRIGHT |
| Hey, you want this? You have it! |