Problem with exporting from GIMP 5.2.0 to TIFF

[ExAdobeUser]

Hi,

Sorry in advance for the length of this post. TLDR version is that exporting an image from GIMP to TIFF format yields weird results.

All of the work described below is taking place on a Dell laptop with Intel x64 processor running 64-bit Windows 10, darktable 5.2.0, and GIMP 3.2.4. My overall goal is to create a composite TIFF image comprising four cropped photos side by side, and then make a print.

I have four cropped photos that were post-edited from camera raw using darktable and exported to TIFF files using darktable settings shown in the attachment darktable_export_settings.jpg. I checked the darktable exports using Windows photo viewer, and they all looked fine.

I next imported the four photos into GIMP, converting the color profile to the built-in GIMP sRGB. I created an appropriately sized empty image and pasted the photos into it, each on a separate layer, and set the X offsets to arrange the photos. Lastly, I put a white background layer on the bottom to show white separator regions. All layers were set to 100% opacity. The attachment GIMP_preview_scrape.jpg shows the contents of the workspace image preview after all of the editing. The preview looks exactly as I intended.

I then exported from GIMP to a new TIFF file using File->Export As... with the settings shown in attachment GIMP_export_settings.jpg. I think the important thing to note is that I exported uncompressed and did not save layers. This is where the problem shows up. I opened the new TIFF file with Windows photo viewer, and it was extremely grainy (see attachment GIMP_export_preview.jpg).

I tried repeating the entire process but exporting from GIMP to JPG, and the final image was flawless. Obviously I could resort to using JPG instead of TIFF to make my print, but I really want to understand where I went wrong in this process.

Any suggestions?

Thanks,

Mike

[rich2005]

Caveat I use linux but I do use Gimp 3.2.4 and did dig out a DT 5.2

I can not reproduce the grainy image that you get with Windows Photo. Not excusing Gimp or DT but if you search there are many posts scattered about re: PhotoEditor displaying images incorrectly. Try another image viewer, XnViewMP showed my 32 FP tiffs perfectly.

Sometimes, a tiff shows a thumbnail (degraded) but you have that turned off.

It is prossibly the bit depth, try exporting the same image as a tiff but 16 bit and also 8 bit - and compare.

Did you use DT for any editing ? Say Desaturation / Scaling / anything else ?
For Gimp before exporting 32bit FP are there any layer effects (fx) still active. Try merging before exporting.

Hopefully a Windows user will come along, Also try posing the question on https://discuss.pixls.us/ Always lots of opinions there.

[ExAdobeUser]

Thanks for the quick response, rich2005.

It did turn out to be M$ Windows. I viewed the output file on an Apple device and also via Photopea, and in both cases the image was perfect. Thanks so much for your time and expertise!

BTW, when I posted the original message, I thought that I attached files, but when I came back here to read your response I couldn't see them anywhere. I think that I followed the instructions at https://www.gimp-forum.net/misc.php?action=help&hid=11 (browse, open, add attachment). Did something on the admin side prevent their inclusion? If not, I'll assume that I messed up somehow and be more careful next time.

Thanks again,

Mike

[rich2005]

(Yesterday, 08:29 PM)ExAdobeUser Wrote: ----snip----
BTW, when I posted the original message, I thought that I attached files, but when I came back here to read your response I couldn't see them anywhere. I think that I followed the instructions at https://www.gimp-forum.net/misc.php?action=help&hid=11 (browse, open, add attachment). Did something on the admin side prevent their inclusion? If not, I'll assume that I messed up somehow and be more careful next time.

   

Oooh, a circular reference, very linux
Looking at your first post, the one with the images, I saw them ok, it probably depends on browser.
You correctly attached the images but just as attachments. Typicallly these would be Gimp scripts or zipped files as well as images.
For images, Next time go one step further and insert the image into the post.