TIFFReadRGBAImage(3tiff) Introduction to Library Functions TIFFReadRGBAImage(3tiff)
NAME
TIFFReadRGBAImage - read and decode an image into a fixed-format raster
SYNOPSIS
#include <tiffio.h>
#define TIFFGetR(abgr) ((abgr) & 0xff)
#define TIFFGetG(abgr) (((abgr) >> 8) & 0xff)
#define TIFFGetB(abgr) (((abgr) >> 16) & 0xff)
#define TIFFGetA(abgr) (((abgr) >> 24) & 0xff)
int TIFFReadRGBAImage(TIFF* tif, u_long width, u_long height, u_long* raster, int stopOnError)
DESCRIPTION
TIFFReadRGBAImage reads a strip- or tile-based image into memory, storing the result in the user-supplied raster. The raster is assumed to
be an array of width times height 32-bit entries, where width must be less than or equal to the width of the image, and height may be any
non-zero size. If the raster dimensions are smaller than the image, the image data is cropped to the raster bounds. If the raster height is
greater than that of the image, then the image data is placed in the lower part of the raster. Note that the raster is assumed to be orga-
nized such that the pixel at location (x,y) is raster[y*width+x], with the raster origin in the bottom-left corner.
EXTENDED DESCRIPTION
Raster pixels are 8-bit packed red, green, blue, alpha samples. The macros TIFFGetR, TIFFGetG, TIFFGetB, and TIFFGetA should be used to
access individual samples. Images without Associated Alpha matting information have a constant Alpha of 1.0(255).
TIFFReadRGBAImage converts non-8-bit images by scaling sample values. Palette, grayscale, bilevel, CMYK, and YCbCr images are converted to
RGB transparently. Raster pixels are returned uncorrected by any colorimetry information present in the directory.
The parameter stopOnError specifies how to act if an error is encountered while reading the image. If stopOnError is non-zero, then an
error terminates the operation. Otherwise, TIFFReadRGBAImage continues to process data until all of the possible data in the image has been
requested.
Samples must be either 1, 2, 4, 8, or 16 bits. Colorimetric samples/pixel must be either 1, 3, or 4 (that is, SamplesPerPixel minus
ExtraSamples).
Palette image colormaps that appear to be incorrectly written as 8-bit values are automatically scaled to 16-bits.
TIFFReadRGBAImage is just a wrapper around the more general TIFFRGBAImage(3tiff) facilities.
Diagnostics
All error messages are directed to the TIFFError(3tiff) routine.
Sorry, can not handle %d-bit pictures.
The image has a BitsPerSample value other than 1, 2, 4, 8, or 16.
Sorry, can not handle %d-channel images.
The image has a SamplesPerPixel value other than 1, 3, or 4.
Missing needed "PhotometricInterpretation" tag.
The image does not have a tag that describes how to display the data.
No "PhotometricInterpretation" tag, assuming RGB.
The image does not have a tag that describes how to display the data, but is assumed to be RGB because the image has 3 or 4 sam-
ples/pixel.
No "PhotometricInterpretation" tag, assuming min-is-black.
The image does not have a tag that describes how to display the data, but is assumed to be a grayscale or bilevel image because the
image has 1 sample/pixel.
No space for photometric conversion table.
There is insufficient memory for a table needed to convert image samples to 8-bit RGB.
Missing required "Colormap" tag.
A Palette image does not have a required Colormap tag.
No space for tile buffer.
There is insufficient memory to allocate an i/o buffer.
No space for strip buffer.
There is insufficient memory to allocate an i/o buffer.
Can not handle format.
The image has a format (combination of BitsPerSample, SamplesPerPixel, and PhotometricInterpretation) that TIFFReadRGBAImage cannot
process.
No space for B&W mapping table.
There is insufficient memory to allocate a table needed to map grayscale data to RGB.
No space for Palette mapping table.
There is insufficient memory to allocate a table needed to map data to 8-bit RGB.
RETURN VALUES
1 is returned if the image was successfully read and converted. Otherwise, 0 is returned if an error was encountered and stopOnError is
zero.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Availability |SUNWTiff |
+-----------------------------+-----------------------------+
|Interface stability |External |
+-----------------------------+-----------------------------+
SEE ALSO
libtiff(3), TIFFOpen(3tiff), TIFFRGBAImage(3tiff), TIFFReadRGBAStrip(3tiff), TIFFReadRGBATile(3tiff)
NOTES
Orientations other than bottom-left or top-left are not processed correctly.
In C++, the stopOnError parameter defaults to 0.
This man page was originally written by Sam Leffler. Updated by Breda McColgan, Sun Microsystems Inc., 2004.
SunOS 5.10 05 Apr 2004 TIFFReadRGBAImage(3tiff)