Is it possible to compress 48-bit TIFFs?

Discussions on NConvert - the command line tool for image conversion and manipulation

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DrFrag
Posts: 2
Joined: Mon Feb 27, 2023 9:35 am

Is it possible to compress 48-bit TIFFs?

Post by DrFrag »

I have some uncompressed 48-bit TIFFs I'm storing at maximum quality for archival purposes, and I'd like to use lossless compression to reduce the storage size. When I try any compression method with NConvert, it changes them to 24-bit TIFF. I'm using v7.136 under Windows 7.

Is it even possible to compress 48-bit images? Or is that unsupported by NConvert or the TIFF format? I noticed the # of colors displayed when using the -info parameter is 16777216 for 48 bit images, which seems wrong to me.

Here is an example 48-bit image I'm using: https://mega.nz/file/upIGhLrJ#uMSochdL8 ... vOnDbhR-pI

Here's an example of the parameters I used: nconvert.exe -o WaterlooBridge1971compressed.tif -out tiff -c 3 WaterlooBridge1971.tif

I've tried including the -org_depth parameter but it just causes the process to sit on 13% CPU usage and never finish.
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xnview
Author of XnView
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Joined: Mon Oct 13, 2003 7:31 am
Location: France

Re: Is it possible to compress 48-bit TIFFs?

Post by xnview »

ok, will be fixed. But '-c 3' produces a bigger file
Pierre.
DrFrag
Posts: 2
Joined: Mon Feb 27, 2023 9:35 am

Re: Is it possible to compress 48-bit TIFFs?

Post by DrFrag »

Thank you! :D