TIFFReadRGBAStrip

Synopsis

#include <tiffio.h>

int TIFFReadRGBAStrip(TIFF *tif, uint32_t row, uint32_t *raster)

int TIFFReadRGBAStripExt(TIFF *tif, uint32_t row, uint32_t *raster, int stop_on_error)

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 ImageWidth × RowsPerStrip 32-bit entries, where ImageWidth is the width of the image (TIFFTAG_IMAGEWIDTH) and RowsPerStrip is the maximum lines in a strip (TIFFTAG_ROWSPERSTRIP).

TIFFReadRGBAStripExt() provides the parameter stop_on_error. Its behaviour is described at TIFFReadRGBAImage.

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 page for more details on how various image types are converted to RGBA values.

Notes

TIFFReadRGBAStrip() is just a wrapper around the more general TIFFRGBAImage 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.

For general notes see TIFFRGBImage notes.

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 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\fP:

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)