TIFFReadRGBAStrip(3tiff) Introduction to Library Functions TIFFReadRGBAStrip(3tiff)
NAME
TIFFReadRGBAStrip - read and decode an image strip 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 TIFFReadRGBAStrip(TIFF* tif, tstrip_t strip, uint32 * raster )
DESCRIPTION
TIFFReadRGBAStrip reads a single strip of a strip-based image into memory, storing the result in the user-supplied RGBA raster. The raster
is assumed to be an array of width times rowsperstrip 32-bit entries, where width is the width of the image (TIFFTAG_IMAGEWIDTH), and
rowsperstrip is the maximum number of lines in a strip (TIFFTAG_ROWSPERSTRIP).
The strip value should be the strip number (the first strip is strip zero) as returned by the TIFFComputeStrip function, but always for
sample 0.
Note that the raster is assumed to be organized such that the pixel at location (x,y) is raster[y*width+x], with the raster origin in the
bottom-left corner of the strip. That is, bottom-to-top organization. When reading a partial last strip in the file, the last line of the
image begins at the beginning of the buffer.
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).
See TIFFRGBAImage(3tiff) for more information about how various image types are converted to RGBA values.
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 TIFFReadRGBAStrip 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.
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), TIFFReadRGBAImage(3tiff), TIFFReadRGBATile(3tiff)
NOTES
Orientations other than bottom-left or top-left are not processed correctly.
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.
TIFFReadRGBAStrip is just a wrapper around the more general TIFFRGBAImage(3tiff) facilities. The main advantage of TIFFReadRGBAStrip over
the similar TIFFReadRGBAImage() function is that for large images, it is not necessary to allocate a single buffer capable of holding the
whole image. The buffer only needs to hold one strip. The TIFFReadRGBATile() function performs a similar operation for tiled images.
This man page was originally written by Sam Leffler. Updated by Breda McColgan, Sun Microsystems Inc., 2004.
SunOS 5.10 05 Apr 2004 TIFFReadRGBAStrip(3tiff)