TiffWriter: incorrect BigTIFF threshold

[dgault]

Issue was raised on forum thread https://forum.image.sc/t/possible-bio-formats-bfconvert-bigtiff-threshold-bug/88042

The user reported an exception when attempting to write 8 planes each of 429.9 Mb so a total data size of 3.44Gb. An exception is then thrown from the TiffWriter as it checks if there is enough space for 2 full planes from the end of the output stream:

bioformats/components/formats-bsd/src/loci/formats/out/TiffWriter.java

Lines 381 to 387 in e484e1f

	if (!isBigTiff) {
	isBigTiff = (out.length() + 2
	* (width * height * c * bytesPerPixel)) >= 4294967296L;
	if (isBigTiff) {
	throw new FormatException("File is too large; call setBigTiff(true)");
	}
	}

I was able to reproduce locally by writing an uncompressed file of size 12000 * 20000 * 2 * 8. If I manually override the check then a valid TIFF file is written under the threshold size and validates with tiffinfo.

[imagesc-bot]

This issue has been mentioned on Image.sc Forum. There might be relevant details there:

https://forum.image.sc/t/possible-bio-formats-bfconvert-bigtiff-threshold-bug/88042/4