I have an idea for a hacky workaround, but I don't know if it could work:
Concept:
I have a folder ("originals") with my image files and a folder ("copy") that has pure white images* with the same names and dimensions.
If it is possible to write some JS in the copy folder that changes this
<img data-src="/content/copy/image-1.jpg" data-width="1920" alt="Image 1" itemprop="thumbnail" src="/render/w480/copy/image-1.jpg">
to this
<img data-src="/content/originals/image-1.jpg" data-width="1920" alt="Image 1" itemprop="thumbnail" src="/render/w480/originals/image-1.jpg">
I assume it should work?
I found a general direction here:
https://stackoverflow.com/questions/132 ... javascript
So something roughly like this:
var images = document.getElementsByTagName("img");
for (var i = 0; i < images.length; i++) {
data-temp = images[i].data-src
images[i].data-src = data-temp.replace(originals, copy)
src-temp = images[i].src
images[i].src = src-temp.replace(originals, copy)
}
It's probably evident I am not a coder and I don't know JS, but I hope it's enough to make my idea comprehensible.
* a pure white or black JPG with 1920x1280px, quality 0 and MozJpeg compression comes in around 12kB. This was the smallest file sized dummy solution I could think of. At first I wanted to use a 1x1px image but I guess then the src path to the render file would make no sense.