TIFF alpha channel mode masked / selected areas (PS)

Started by cscwth, September 02, 2020, 06:53:58 AM

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cscwth

Hi folks,
first a disclaimer: this is my first posting here and I probably don't have caught up on the terminology (i.e. the right keywords for google and the forum search). Be gentle and move the thread to the right subforum if necessary ;)

Back to my question.
I want to build some kind of validation for TIFF files that come out of Photoshop. The files must have an alpha channel in a way that the white areas are opaque and the black ones are transparent. We use Photoshop for image processing and unfortunately for this use case, PS has an option to "invert" the alpha channel (see attached alpha.PNG).
The color can either indicate masked areas or selected areas. I need it to be set to "selected areas" (to be confirmed)

Is there a way to check this setting with exiftool?

Example files attached

StarGeek

Quote from: cscwth on September 02, 2020, 06:53:58 AM
Is there a way to check this setting with exiftool?

Comparing the output of your example files, no, it doesn't appear that exiftool will be able to check this.  It doesn't appear that photoshop saves this data.

The exiftool output of the two files is nearly identical, except for some timestamps and ID.
* Did you read FAQ #3 and use the command listed there?
* Please use the Code button for exiftool code/output.
 
* Please include your OS, Exiftool version, and type of file you're processing (MP4, JPG, etc).

cscwth

Thx. I don't know if this is the right tool for what I want to achieve, but besides ImageMagick, exiftool is the only thing I have available on the pizza box right now.

Quote from: StarGeek on September 02, 2020, 10:35:16 AM
It doesn't appear that photoshop saves this data.

PS works in magical ways sometimes. I can open one of the files and have the "masked" option ticked in the settings of the alpha channel. And when I open the other file, the "selected" option is ticked. PS seems to save at least something.

I'm using the attached config file to extract the layer names. Is there maybe a way to get to the properties of each layer?

StarGeek

I'm assuming that config file is the one from the main config repository?  If so, that adding that doesn't seem to help.

Adding the -u (unknown) option does pull up an extra couple tags where there's a difference, but it's data hasn't been decoded.
========= Y:/!temp/ccccc/a/11258392_adim_P2-ausgew-bereich-1.tif
---- Photoshop ----
DisplayInfo                     : ..t#M.‡2
DisplayInfo                     : .ÿÿ2
======== Y:/!temp/ccccc/a/11258392_adim_P2-maskierter-bereich-1.tif
---- Photoshop ----
DisplayInfo                     : ..t#M.‡2.
DisplayInfo                     : .ÿÿ2.
* Did you read FAQ #3 and use the command listed there?
* Please use the Code button for exiftool code/output.
 
* Please include your OS, Exiftool version, and type of file you're processing (MP4, JPG, etc).

cscwth

Quote from: StarGeek on September 02, 2020, 12:19:20 PM
I'm assuming that config file is the one from the main config repository

I guess...it's been a while. Although I probably found this somewhere in a forum post. It's quite useful though. I can use it to ensure that there are certain paths with certain names, no surplus layers, etc. It's all part of QA.

Quote from: StarGeek on September 02, 2020, 12:19:20 PM
Adding the -u (unknown) option does pull up an extra couple tags where there's a difference, but it's data hasn't been decoded.

Bummer. But OK. Then the QA guys may have to do some of the work by themselves after all.

Thank you.

Hubert

Somewhat OT...

Have you tried scripting? I don't have Photoshop to give concrete examples, but if you follow the links at Adobe's Photoshop Scripting page https://www.adobe.com/devnet/photoshop/scripting.html, there is comprehensive documentation for channels in AppleScript ("kind" can be "masked area channel", "selected area channel" etc) and vbScript ("psChannelType") and JavaScript (beyond me) which looks as though it might help.

cscwth

You know what? I thought of that. We do actually use PS scripting for batch processing of a large number of images, but there's nobody around who really knows how this all works. (And I don't want to become that guy because I know what's going to happen then. No, thank you).

But I'll try to bring this up. Maybe we can find someone who is willing to open this Pandora's box....

Hubert

Quote from: cscwth on September 03, 2020, 04:04:44 AM
I don't want to become that guy because I know what's going to happen then.

;D

Knowing a bit of scripting kept me in a job for several years...