TIFFReadRGBAStrip(3tiff)

TIFFReadRGBAStrip(3TIFFMISC. REFERENCE MANUAL PAGETIFFReadRGBAStrip(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 ras-
     ter 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  sam-
     ples.  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.  SamplesPer-
     Pixel minus ExtraSamples).

     Palette image colormaps that appear to be incorrectly  writ-
     ten as 8-bit values are automatically scaled to 16-bits.

libtiff          Last change: December 10, 1998                 1

TIFFReadRGBAStrip(3TIFFMISC. REFERENCE MANUAL PAGETIFFReadRGBAStrip(3TIFF)

     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  con-
     verted.   Otherwise,  0  is returned if an error was encoun-
     tered.

DIAGNOSTICS

     All error messages are directed to the TIFFError(3TIFF) rou-
     tine.

     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 Sam-
     plesPerPixel 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 insuf-
     ficient  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 PhotometricInterpre-
     tation) that TIFFReadRGBAImage can not handle.

libtiff          Last change: December 10, 1998                 2

TIFFReadRGBAStrip(3TIFFMISC. REFERENCE MANUAL PAGETIFFReadRGBAStrip(3TIFF)

     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

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

libtiff          Last change: December 10, 1998                 3