2007.08.22 06:19 "[Tiff] Get random lines using TIFFReadScanline()", by Oliver Geisen
Hello,
as far as i know the function can only handle subsequent lines (no random access).
The API of this function is not very good, because it implies some random access to the programmer by using the 'row' property. Maybe it would be better this way:
TIFFReadFirstScanline()
TIFFReadNextScanline()
Here is a way to provide random access for TIFFReadScanline:
strip = (row / rps); // points to the absolute strip (do -1 to
get an offset)
stripsize = TIFFStripSize(tiff);
TIFFReadEncodedStrip(tiff, strip, stripdata, stripsize);
stripline = (row % rps); // get the line# inside the striplinesize = TIFFScanlineSize(tiff); // get the size of one line
offset = (stripline-1) * linesize; // offset from stripdata tobegin of line
return (stripdata + offset); // return pointer to wanted line
Oliver Geisen
Systemadministrator
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