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Req: Add 16bit tiff writing (or at least a warning)
Posted: Thu Oct 08, 2015 10:43 am
by Marsu42
While XnViewMP happily opens 16bit tiff files, when saving them it silently discards half of the data and saves as 8 bit. That's unfortunate, as esp. with a lossless format you're bound to assume that you can happily save w/o any loss of quality. Note that 16bit tiff is a very common format esp. when exporting anything 14bit-ish from a digital camera raw format to a postprocessing app.
Req: Support 16bit tiff saving or at least add a warning when force-converting to 8bit.
Re: Req: Add 16bit tiff writing (or at least a warning)
Posted: Fri Oct 09, 2015 12:49 am
by photoken
I agree that 16-bit TIF should be fully supported.
However, XnViewMP (0.72) does display a warning when the 16-bit TIF is opened, saying that it will be converted to 8-bit.
Re: Req: Add 16bit tiff writing (or at least a warning)
Posted: Sat Oct 10, 2015 6:04 am
by Marsu42
photoken wrote:However, XnViewMP (0.72) does display a warning when the 16-bit TIF is opened, saying that it will be converted to 8-bit.
I'm in bad luck then, mine (0.75 Win64) doesn't at any time? My workflow: open 16bit tiff (either through the browser or command line), select "Save" or "Save As" ...*boom* data loss = conversion to 8bit.
Re: Req: Add 16bit tiff writing (or at least a warning)
Posted: Sun Oct 25, 2015 12:42 am
by foxyshadis
XnView doesn't have any 16-bit support at all, which is a bit of a bummer. It doesn't even seem to dither down, just chops the low bits off.
The warning might not show if you've disabled it at some point in the past. On the settings->General page, try resetting all confirm prompts and see if that helps.
Re: Req: Add 16bit tiff writing (or at least a warning)
Posted: Sun Oct 25, 2015 8:59 am
by Marsu42
foxyshadis wrote:The warning might not show if you've disabled it at some point in the past. On the settings->General page, try resetting all confirm prompts and see if that helps.
Thanks, will do.
Looking at ImageMagick q8 vs q16, adding 16bit results in a big speed loss - I don't know if it would be the same with XnView or if the libs used all support 16bit at all. However, as more high-bit images become available with digital photography and hdr, plus computers get faster, imho it would be worth it to add it to XnView.