plucky (3) TIFFReadRGBAImage.3tiff.gz

Provided by: libtiff-dev_4.5.1+git230720-4ubuntu4_amd64 bug

NAME
       TIFFReadRGBAImage - read and decode an image into a fixed-format raster


SYNOPSIS
          #include <tiffio.h>

       TIFFGetR(abgr)
              ((abgr)&0xff)

       TIFFGetG(abgr)
              (((abgr) >> 8) & 0xff)

       TIFFGetB(abgr)
              (((abgr) >> 16) & 0xff)

       TIFFGetA(abgr)
              (((abgr) >> 24) & 0xff)

       int TIFFReadRGBAImage(TIFF *tif, uint32_t width, uint32_t height, uint32_t *raster, int stopOnError)

       int   TIFFReadRGBAImageOriented(TIFF  *tif,  uint32_t  width,  uint32_t  height,  uint32_t  *raster,  int
       orientation, int stopOnError)


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 × 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() except that the user can  specify  the  raster
       origin position with the orientation parameter. Four orientations are supported:

       • ORIENTATION_TOPLEFT: origin in top-left corner,

       • ORIENTATION_TOPRIGHT: origin in top-right corner,

       • ORIENTATION_BOTLEFT: origin in bottom-left corner

       • ORIENTATION_BOTRIGHT: origin in bottom-right corner.

       If you choose ORIENTATION_BOTLEFT, the 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  parameter  stopOnError  specifies  how to act if an error is encountered while reading the image. If
       stopOnError 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.

       SamplesPerPixel  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).

       Palettte image colormaps that appear to be incorrectly written as 8-bit values are  automatically  scaled
       to 16-bits.

       IFFReadRGBAImage() is just a wrapper around the more general TIFFRGBAImage 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 TIFFErrorExtR() 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),  TIFFReadRGBAStrip (3tiff), TIFFReadRGBATile (3tiff), libtiff
       (3tiff)


AUTHOR
       LibTIFF contributors


       1988-2024, LibTIFF contributors