Question: tags in tiff file from RT

Hello again RT forum,

I converted a Canon CR2 RAW to 16-bit TIFF using RT Queue with RTv4-Medium output profile with Rendering intent “relative colorimetric”. The files are here. (The image is part of a focus stack).
filebin link, as an alternative.

  1. I get “Rendering Intent : Perceptual” as a tag in the TIFF file. Should this be “Rendering Intent : Relative Colorimetric”, or similar? Does this matter for a printer receiving the TIFF file?
    Command: exiftool _Y8A8348-AdobeRGB.tif | grep Rendering
    Result: Rendering Intent : Perceptual

  2. Command: identify _Y8A8348-AdobeRGB.tif displays as:
    _Y8A8348-AdobeRGB.tif TIFF 4492x6732 4492x6732+0+0 16-bit sRGB 173.045MiB 0.000u 0:00.000.
    This the Imagemagick command identify. I wonder why identify outputs “sRGB”? (This is ultimately a question to Imagemagick developers).
    However, Command:
    identify -verbose _Y8A8348-AdobeRGB.tif | grep Colorspace
    “Colorspace: sRGB”.
    Why is “Colorspace” set to “sRGB” in RT TIFF output when I pick RTv4_medium (AdobeRGB) as output profile?

There are hundreds of lines of data from identify -verbose and exiftool. Honestly, I do not know if the output above matters at all. Perhaps my 16-bit tiff file renders perfectly when printed at the printing company and tags quoted are irrelevant? I do not know.

Debian Testing
RT 5.8-2838-g8bf1098d7 from source

Ok, for question 1, the “Rendering Intent : Perceptual” seems to originate from the working and output profiles in RT.

exiftool RTv4_Medium and
exiftool RTv4_large
both have
“Rendering Intent : Perceptual”

This was also the feedback from the printing company, in my case. They try to use the embedded profile’s rendering intent.

Did you use the fast export, the batch queue, or a one by one export?

I used “put image to queue” from main edit window for the CR2 RAW file and then in queue tab I selected tiff (16-bit) and pressed “on”. I exported only one picture. I did not use “save current image” from main window.

Could you shrink your image and plop it into a post? I can’t download from your link for some reason.

Try this filebin link, as an alternative.

A new link to Google drive is here:
(The intention is to give read rights to all with the link)

From my exiftool output:

Rendering Intent                : Perceptual
Profile Description             : RTv4_Medium

Yes, I see the same thing, in the tiff file.

I think, but I do not know that this is picked up from RTv4_Medium.icc output profile which has “Rendering Intent : Perceptual”, or from the working profile RTv4_Large.icc which also has “Rendering Intent : Perceptual”.
(in post number 2).

Should this be “relative colorimetric” instead, since I choose this intent when I created the TIFF file? Or “perceptual” is the de facto standard for printing AdobeRGB (RTv4_Medium.icc) and is therefore the default. A user who want to change this has to edit RTv4_Medium.icc Rendering Intent default?

I am uncertain if this answers your question:

Also see: