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.simplesystems.org/libtiff/