Gimp-Forum.net

Hi all,

Gimp-noob here. I have a bunch of high res scans of artwork that were saved as Tiff files, but whenever i try to open them, this message is displayed: 
"Non-conformant TIFF: extra channels without 'ExtraSamples" field. Process extra channel as: 
Non-premultiplied alpha; 
Premultiplied alpha; 
Channel."

Whichever one of those three options i choose, the picture just opens up as entirely green.

All I'm looking to do is open the tiff file, edit the image, keep it/save it as a tiff file, as this is the preference of the local print shop I want to use. How can I do this? How can I get the image to open?

Appreciate any and all help!!

What format is the scan? 8 bit or 16 bit and what compression if any. (suspect embedded color profile for the color change) I can open a tif, get those three options, leave default, click import and that works here.

A couple of possibilities that work here to bypass the 3 options (using 16 bit tiff)

Rawtherapee (RT) https://rawtherapee.com/ Especially if it is a 16 bit tiff. Open the tiff. If it opens correctly, save straight away to another some-new-name. tiff. Various save options see: https://i.imgur.com/M9DAthE.jpg I tried a 16 bit and 16 bit float both bypass the Gimp warning & just ask about the colour profile. (Just my opinion but RT has one of the worst interfaces I have seen).

ImageMagick (IM) https://imagemagick.org/ Command line as


That makes a rather large uncompressed out.tiff that opens straight up in Gimp, looks like it strips out any color profile, strangely opens as 32 bit.

edit: Just a thought, some scanning software such a vuescan will embed a preview thumbnail image. That will show up in Gimp as pages in the Open dialogue. Do you get anything like that ?