TIFFReadRGBAImage(3TIFF)               TIFFReadRGBAImage(3TIFF)





NAME
       TIFFReadRGBAImage,  TIFFReadRGBAImageOriented - 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)
       int  TIFFReadRGBAImageOriented(TIFF  *tif, u_long width,
       u_long height, u_long *raster, int orientation, int sto-
       pOnError)

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 (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 are placed in the
       lower part of the raster.   (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.)

       TIFFReadRGBAImageOriented  works  like TIFFReadRGBAImage
       with except of that user can specify the  raster  origin
       position  with  the orientation parameter. Four orienta-
       tions supported:

       ORIENTATION_TOPLEFT
              origin in top-left corner,

       ORIENTATION_TOPRIGHT
              origin in top-right corner,

       ORIENTATION_BOTLEFT
              origin in bottom-left corner and

       ORIENTATION_BOTRIGHT
              origin in bottom-right corner.

       If you choose ORIENTATION_BOTLEFT  result  will  be  the
       same as returned by the TIFFReadRGBAImage.

       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  paramater  stopOnError  specifies  how to act if an
       error is encountered while reading the image.   If  sto-
       pOnError  is  non-zero, then an error will terminate the
       operation;  otherwise  TIFFReadRGBAImage  will  continue
       processing data until all the possible data in the image
       have been requested.

NOTES
       In C++ the stopOnError parameter defaults to 0.

       Samples must be either 1, 2, 4, 8, or 16 bits.   Colori-
       metric  samples/pixel  must  be  either 1, 3, or 4 (i.e.
       SamplesPerPixel minus ExtraSamples).

       Palettte 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 gen-
       eral TIFFRGBAImage(3TIFF) facilities.

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.

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  mem-
       ory to allocate an i/o buffer.

       Can not handle format.  The image has a format (combina-
       tion  of  BitsPerSample,  SamplesPerPixel,  and   Photo-
       metricInterpretation)  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  insuffi-
       cient  memory  to  allocate  a table used to map data to
       8-bit RGB.

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



libtiff                 October 29, 200TIFFReadRGBAImage(3TIFF)
