src/tiff/man/TIFFReadRGBATile.3tiff

.\" $Id: TIFFReadRGBATile.3tiff,v 1.2 2005/11/02 11:07:18 dron Exp $
.\"
.\" Copyright (c) 1991-1997 Sam Leffler
.\" Copyright (c) 1991-1997 Silicon Graphics, Inc.
.\"
.\" Permission to use, copy, modify, distribute, and sell this software and
.\" its documentation for any purpose is hereby granted without fee, provided
.\" that (i) the above copyright notices and this permission notice appear in
.\" all copies of the software and related documentation, and (ii) the names of
.\" Sam Leffler and Silicon Graphics may not be used in any advertising or
.\" publicity relating to the software without the specific, prior written
.\" permission of Sam Leffler and Silicon Graphics.
.\"
.\" THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND,
.\" EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY
.\" WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
.\"
.\" IN NO EVENT SHALL SAM LEFFLER OR SILICON GRAPHICS BE LIABLE FOR
.\" ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,
.\" OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
.\" WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF
.\" LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
.\" OF THIS SOFTWARE.
.\"
.if n .po 0
.TH TIFFReadRGBATile 3TIFF "December 10, 1998" "libtiff"
.SH NAME
TIFFReadRGBATile \- read and decode an image tile into a fixed-format raster
.SH SYNOPSIS
.B "#include <tiffio.h>"
.sp
.B "#define TIFFGetR(abgr)	((abgr) & 0xff)"
.br
.B "#define TIFFGetG(abgr)	(((abgr) >> 8) & 0xff)"
.br
.B "#define TIFFGetB(abgr)	(((abgr) >> 16) & 0xff)"
.br
.B "#define TIFFGetA(abgr)	(((abgr) >> 24) & 0xff)"
.sp
.BI "int TIFFReadRGBATile(TIFF *" tif ", uint32 " x ", uint32 " y ", uint32 *" raster ")"
.SH DESCRIPTION
.IR TIFFReadRGBATile
reads a single tile of a tile-based image into memory, storing the result in
the user supplied RGBA
.IR raster .
The raster is assumed to be an array of width times length 32-bit entries,
where width is the width of a tile (TIFFTAG_TILEWIDTH) and length is the
height of a tile (TIFFTAG_TILELENGTH).

.PP
The
.IR x
and
.IR y
values are the offsets from the top left corner to the top left corner of the
tile to be read.  They must be an exact multiple of the tile width and length.

.PP
Note that the raster is assume to be organized such that the pixel at location
(\fIx\fP,\fIy\fP) is \fIraster\fP[\fIy\fP*\fIwidth\fP+\fIx\fP]; with the
raster origin in the
.I lower-left hand corner
of the tile. That is bottom to top organization.  Edge tiles which partly fall
off the image will be filled out with appropriate zeroed areas.

.PP
Raster pixels are 8-bit packed red, green, blue, alpha samples. The macros
.IR TIFFGetR ,
.IR TIFFGetG ,
.IR TIFFGetB ,
and
.I TIFFGetA
should be used to access individual samples. Images without Associated Alpha
matting information have a constant Alpha of 1.0 (255).
.PP
See the
.IR TIFFRGBAImage (3TIFF)
page for more details on how various image types are converted to RGBA values.
.SH NOTES
Samples must be either 1, 2, 4, 8, or 16 bits. Colorimetric samples/pixel must
be either 1, 3, or 4 (i.e.
.I SamplesPerPixel
minus
.IR ExtraSamples ).
.PP
Palette image colormaps that appear to be incorrectly written as 8-bit values
are automatically scaled to 16-bits.
.PP
.I TIFFReadRGBATile
is just a wrapper around the more general
.IR TIFFRGBAImage (3TIFF)
facilities.  It's main advantage over the similar
.IR TIFFReadRGBAImage()
function is that for large images a single buffer capable of holding the whole
image doesn't need to be allocated, only enough for one tile.  The
.IR TIFFReadRGBAStrip()
function does a similar operation for stripped images.
.SH "RETURN VALUES"
1 is returned if the image was successfully read and converted.
Otherwise, 0 is returned if an error was encountered.
.SH DIAGNOSTICS
All error messages are directed to the
.IR TIFFError (3TIFF)
routine.
.PP
.BR "Sorry, can not handle %d-bit pictures" .
The image had
.I BitsPerSample
other than 1, 2, 4, 8, or 16.
.PP
.BR "Sorry, can not handle %d-channel images" .
The image had
.I SamplesPerPixel
other than 1, 3, or 4.
.PP
\fBMissing needed "PhotometricInterpretation" tag\fP.
The image did not have a tag that describes how to display the data.
.PP
\fBNo "PhotometricInterpretation" tag, assuming RGB\fP.
The image was missing a tag that describes how to display it, but because it
has 3 or 4 samples/pixel, it is assumed to be
.SM RGB.
.PP
\fBNo "PhotometricInterpretation" tag, assuming min-is-black\fP.
The image was missing a tag that describes how to display it,
but because it has 1 sample/pixel, it is assumed to be a grayscale
or bilevel image.
.PP
.BR "No space for photometric conversion table" .
There was insufficient memory for a table used to convert
image samples to 8-bit
.SM RGB.
.PP
\fBMissing required "Colormap" tag\fP.
A Palette image did not have a required
.I Colormap
tag.
.PP
.BR "No space for tile buffer" .
There was insufficient memory to allocate an i/o buffer.
.PP
.BR "No space for strip buffer" .
There was insufficient memory to allocate an i/o buffer.
.PP
.BR "Can not handle format" .
The image has a format (combination of
.IR BitsPerSample ,
.IR SamplesPerPixel ,
and
.IR PhotometricInterpretation )
that
.I TIFFReadRGBAImage
can not handle.
.PP
.BR "No space for B&W mapping table" .
There was insufficient memory to allocate a table used to map
grayscale data to
.SM RGB.
.PP
.BR "No space for Palette mapping table" .
There was insufficient memory to allocate a table used to map data to 8-bit
.SM RGB.
.SH "SEE ALSO"
.BR TIFFOpen (3TIFF),
.BR TIFFRGBAImage (3TIFF),
.BR TIFFReadRGBAImage (3TIFF),
.BR TIFFReadRGBAStrip (3TIFF),
.BR libtiff (3TIFF)
.PP
Libtiff library home page:
.BR http://www.remotesensing.org/libtiff/
Commit	Line	Data
	1	.\" $Id: TIFFReadRGBATile.3tiff,v 1.2 2005/11/02 11:07:18 dron Exp $
	2	.\"
	3	.\" Copyright (c) 1991-1997 Sam Leffler
	4	.\" Copyright (c) 1991-1997 Silicon Graphics, Inc.
	5	.\"
	6	.\" Permission to use, copy, modify, distribute, and sell this software and
	7	.\" its documentation for any purpose is hereby granted without fee, provided
	8	.\" that (i) the above copyright notices and this permission notice appear in
	9	.\" all copies of the software and related documentation, and (ii) the names of
	10	.\" Sam Leffler and Silicon Graphics may not be used in any advertising or
	11	.\" publicity relating to the software without the specific, prior written
	12	.\" permission of Sam Leffler and Silicon Graphics.
	13	.\"
	14	.\" THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND,
	15	.\" EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY
	16	.\" WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
	17	.\"
	18	.\" IN NO EVENT SHALL SAM LEFFLER OR SILICON GRAPHICS BE LIABLE FOR
	19	.\" ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,
	20	.\" OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
	21	.\" WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF
	22	.\" LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
	23	.\" OF THIS SOFTWARE.
	24	.\"
	25	.if n .po 0
	26	.TH TIFFReadRGBATile 3TIFF "December 10, 1998" "libtiff"
	27	.SH NAME
	28	TIFFReadRGBATile \- read and decode an image tile into a fixed-format raster
	29	.SH SYNOPSIS
	30	.B "#include <tiffio.h>"
	31	.sp
	32	.B "#define TIFFGetR(abgr) ((abgr) & 0xff)"
	33	.br
	34	.B "#define TIFFGetG(abgr) (((abgr) >> 8) & 0xff)"
	35	.br
	36	.B "#define TIFFGetB(abgr) (((abgr) >> 16) & 0xff)"
	37	.br
	38	.B "#define TIFFGetA(abgr) (((abgr) >> 24) & 0xff)"
	39	.sp
	40	.BI "int TIFFReadRGBATile(TIFF " tif ", uint32 " x ", uint32 " y ", uint32 " raster ")"
	41	.SH DESCRIPTION
	42	.IR TIFFReadRGBATile
	43	reads a single tile of a tile-based image into memory, storing the result in
	44	the user supplied RGBA
	45	.IR raster .
	46	The raster is assumed to be an array of width times length 32-bit entries,
	47	where width is the width of a tile (TIFFTAG_TILEWIDTH) and length is the
	48	height of a tile (TIFFTAG_TILELENGTH).
	49
	50	.PP
	51	The
	52	.IR x
	53	and
	54	.IR y
	55	values are the offsets from the top left corner to the top left corner of the
	56	tile to be read. They must be an exact multiple of the tile width and length.
	57
	58	.PP
	59	Note that the raster is assume to be organized such that the pixel at location
	60	(\fIx\fP,\fIy\fP) is \fIraster\fP[\fIy\fP*\fIwidth\fP+\fIx\fP]; with the
	61	raster origin in the
	62	.I lower-left hand corner
	63	of the tile. That is bottom to top organization. Edge tiles which partly fall
	64	off the image will be filled out with appropriate zeroed areas.
	65
	66	.PP
	67	Raster pixels are 8-bit packed red, green, blue, alpha samples. The macros
	68	.IR TIFFGetR ,
	69	.IR TIFFGetG ,
	70	.IR TIFFGetB ,
	71	and
	72	.I TIFFGetA
	73	should be used to access individual samples. Images without Associated Alpha
	74	matting information have a constant Alpha of 1.0 (255).
	75	.PP
	76	See the
	77	.IR TIFFRGBAImage (3TIFF)
	78	page for more details on how various image types are converted to RGBA values.
	79	.SH NOTES
	80	Samples must be either 1, 2, 4, 8, or 16 bits. Colorimetric samples/pixel must
	81	be either 1, 3, or 4 (i.e.
	82	.I SamplesPerPixel
	83	minus
	84	.IR ExtraSamples ).
	85	.PP
	86	Palette image colormaps that appear to be incorrectly written as 8-bit values
	87	are automatically scaled to 16-bits.
	88	.PP
	89	.I TIFFReadRGBATile
	90	is just a wrapper around the more general
	91	.IR TIFFRGBAImage (3TIFF)
	92	facilities. It's main advantage over the similar
	93	.IR TIFFReadRGBAImage()
	94	function is that for large images a single buffer capable of holding the whole
	95	image doesn't need to be allocated, only enough for one tile. The
	96	.IR TIFFReadRGBAStrip()
	97	function does a similar operation for stripped images.
	98	.SH "RETURN VALUES"
	99	1 is returned if the image was successfully read and converted.
	100	Otherwise, 0 is returned if an error was encountered.
	101	.SH DIAGNOSTICS
	102	All error messages are directed to the
	103	.IR TIFFError (3TIFF)
	104	routine.
	105	.PP
	106	.BR "Sorry, can not handle %d-bit pictures" .
	107	The image had
	108	.I BitsPerSample
	109	other than 1, 2, 4, 8, or 16.
	110	.PP
	111	.BR "Sorry, can not handle %d-channel images" .
	112	The image had
	113	.I SamplesPerPixel
	114	other than 1, 3, or 4.
	115	.PP
	116	\fBMissing needed "PhotometricInterpretation" tag\fP.
	117	The image did not have a tag that describes how to display the data.
	118	.PP
	119	\fBNo "PhotometricInterpretation" tag, assuming RGB\fP.
	120	The image was missing a tag that describes how to display it, but because it
	121	has 3 or 4 samples/pixel, it is assumed to be
	122	.SM RGB.
	123	.PP
	124	\fBNo "PhotometricInterpretation" tag, assuming min-is-black\fP.
	125	The image was missing a tag that describes how to display it,
	126	but because it has 1 sample/pixel, it is assumed to be a grayscale
	127	or bilevel image.
	128	.PP
	129	.BR "No space for photometric conversion table" .
	130	There was insufficient memory for a table used to convert
	131	image samples to 8-bit
	132	.SM RGB.
	133	.PP
	134	\fBMissing required "Colormap" tag\fP.
	135	A Palette image did not have a required
	136	.I Colormap
	137	tag.
	138	.PP
	139	.BR "No space for tile buffer" .
	140	There was insufficient memory to allocate an i/o buffer.
	141	.PP
	142	.BR "No space for strip buffer" .
	143	There was insufficient memory to allocate an i/o buffer.
	144	.PP
	145	.BR "Can not handle format" .
	146	The image has a format (combination of
	147	.IR BitsPerSample ,
	148	.IR SamplesPerPixel ,
	149	and
	150	.IR PhotometricInterpretation )
	151	that
	152	.I TIFFReadRGBAImage
	153	can not handle.
	154	.PP
	155	.BR "No space for B&W mapping table" .
	156	There was insufficient memory to allocate a table used to map
	157	grayscale data to
	158	.SM RGB.
	159	.PP
	160	.BR "No space for Palette mapping table" .
	161	There was insufficient memory to allocate a table used to map data to 8-bit
	162	.SM RGB.
	163	.SH "SEE ALSO"
	164	.BR TIFFOpen (3TIFF),
	165	.BR TIFFRGBAImage (3TIFF),
	166	.BR TIFFReadRGBAImage (3TIFF),
	167	.BR TIFFReadRGBAStrip (3TIFF),
	168	.BR libtiff (3TIFF)
	169	.PP
	170	Libtiff library home page:
	171	.BR http://www.remotesensing.org/libtiff/