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, uint32 row, 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 lines in a strip (TIFFTAG_ROWSPERSTRIP).


     The row value should be the row of the first row in the strip (strip *
     rowsperstrip, zero based).


     Note that the raster is assume to be organized such that the pixel at
     location (x,y) is raster[y*width+x]; with the raster origin in the
     lower-left hand 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
     will begin at the beginning of the buffer.


     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 the TIFFRGBAImage(3TIFF) page for more details on how various image
     types are converted to RGBA values.

NOTES
     Samples must be either 1, 2, 4, 8, or 16 bits. Colorimetric samples/pixel
     must be either 1, 3, or 4 (i.e.  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.  It's main advantage over the similar
     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 strip.  The TIFFReadRGBATile() function does a similar
     operation for tiled images.

RETURN VALUES
     1 is returned if the image was successfully read and converted.
     Otherwise, 0 is returned if an error was encountered.

DIAGNOSTICS
     All error messages are directed to the TIFFError(3TIFF) routine.

     Sorry, can not handle %d-bit pictures.  The image had BitsPerSample other
     than 1, 2, 4, 8, or 16.

     Sorry, can not handle %d-channel images.  The image had SamplesPerPixel
     other than 1, 3, or 4.

     Missing needed "PhotometricInterpretation" tag.  The image did not have a
     tag that describes how to display the data.

     No "PhotometricInterpretation" tag, assuming RGB.  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 RGB.

     No "PhotometricInterpretation" tag, assuming min-is-black. 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.

     No space for photometric conversion table.  There was insufficient memory
     for a table used to convert image samples to 8-bit RGB.

     Missing required "Colormap" tag.  A Palette image did not have a required
     Colormap tag.

     No space for tile buffer.  There was insufficient memory to allocate an
     i/o buffer.

     No space for strip buffer.  There was 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 can not handle.

     No space for B&W mapping table.  There was insufficient memory to
     allocate a table used to map grayscale data to RGB.

     No space for Palette mapping table.  There was insufficient memory to
     allocate a table used to map data to 8-bit RGB.

SEE ALSO
     TIFFOpen(3TIFF), TIFFRGBAImage(3TIFF), TIFFReadRGBAImage(3TIFF),
     TIFFReadRGBATile(3TIFF), libtiff(3TIFF)

     Libtiff library home page:  http://www.remotesensing.org/libtiff/