I think we do have the same problem / use case ...
Let me explain in Adobe terms, but i'm open to any other workflow that does not duplicate files (handling that is not an option with our catalogue).
I do have a product image on white background and a grey drop shadow, in a flat jpg file. No transparencies are involved, neither on layers nor as alpha transparency on pixels.
In photoshop, with the path palette, i draw a vector path (path palette, not masks!) and name it "clippingpath123". This path just lives "in" the image with no visual effect in Photoshop (it's not a vector shape that is visible as an object, and it's also not a mask applied on a layer but the image as a whole). I draw that path so that it lies around the object without the shadow. Saving that file as jpg keeps that vector path inside the file. I assume this is some meta data if it's not within the jpg specification? (exactly the same thing goes for tif files, this works with them equally.)
Background: We get these jpg images from our photographing agency / customers. It's far faster for them to create clipping paths than doing real alpha transparency for the shadows. We have catalogues of thousands of these images from past projects and new ones coming in.
Now, if i place that image in Indesign, the image is visible with its white background as a rectangle.
I can now go to Object > Clipping Path > Options > select "photoshop path" > select the path by its name given > apply.
Now, the image (the main object) is shown within the path shape, everything else is clipped away (including the shadow).
Now I duplicate that image and send it to the background, then remove the clipping setting again for the copy only, and set that object to multiply.
Now if i have something else in the very background that is not white, the whole image (including the shadow) of my image is multiplied on that background (making the shadow pseudo transparent). If i then place my first copy (with clipping, and no multiply effect) on top of that, i preserve the main content (the object) without multiply effects and keep it in its original color. Both grouped together means i finally get a clipped object with a multiplied shadow on a background.
In shorter words: in Indesign, i have two copies of the same image: once with a clipping applied, and once with "multiply" applied. stacked upon each other and grouped, i get a transparent shadow and maintain the main image intact.
This can be scripted so all those steps can be done with applying a keyboard shortcut.
So in affinity programs:
in APhoto, the clipping path embedded in such a jpg does not seem to be visible anywhere (neither as mask on a layer nor elsewhere – or i'm not looking at the right spot?)
in APublisher, placing that image just creates the rectangle with white background, no option to apply the clipping on the image then (or i'm not looking at ther right spot?)
If i open an image in Aphoto, and there (not in photoshop) create a clipping mask on a layer, set the checkbox in jpg export to convert that into a clip path, and then re-open that jpg in Aphoto, i can see a clip path applied to that layer (visually in the image, and in the layers pallette) – so it's somewhat actually there?
If i place THAT Aphoto-clipped jpg in Apublisher, that clipping is not applied though ... it's always a rectangle. If i double click that image to "edit" it within publisher(?), i see the clipping path applied though. If i save / close, it's gone in publisher layout again. If i open it that way, copy that clipped layer, close it, and then paste that copy into the layout, i get the clipped version. But that's quite a drag to place it exactly on top of the first copy, so ... not really an option(?)
Also, re-creating the paths in Aphoto also is not an option ...
So question is:
Is there anything i have overlooked, or is it just not (yet?) possible to do it that way?
Thing is, i've worked in several agencies by now and it seems to be common practice to work with product images that way – it may be old-fashioned and only an "adobe standard", but the existing data is real and can't be converted that easily.
