I am editing an impress presentation at the moment and I duplicate a loot of images.
Are these symlinked from one source? Because then you could use them as often as you want and not increase its size.
But if they are really duplicated, this would be pretty horrible.
Does copy-paste in the App symlink the images? Or is there any option to do so?
Yes they are.
Answering for writer part of the question (according to tag).
It depends on how you configure your image which in turn depends on what you need.
Basically, every instance pasted in the document is independent of the others. This is reported by the Navigator where you see on Image99 per instance. Even if you linked to some file, the document contains one descriptor per occurrence to be able to manage occurrences separately. This increases document size but not as much as with embedded images.
If your images are considered in fact a single “entity”, like a bullet, which should be changed simultaneously in every occurrence, this is not possible with copy & paste because there is no “central descriptor”. You must use a more sophisticated indirect approach in the spirit of bulleted list.
The list style trick ensures there is a single occurrence of the image in the document and a single descriptor, thus keeping document to minimal size. But note that the trick does not cover all use cases. It is valid only for bullet list-like layout, e.g. a warning icon in the margin of a caveat paragraph.
The trick may work the same in Impress but I had no need for it, so I didn’t test it.
Create a user list style where your bullet is the image. Image position (relative to paragraph) can be tuned with the usual list style controls within some limits. Apply this list style to paragraphs requiring the image. The image will change in every occurence when you modify the list style.
IMHO, the question doesn’t make sense in Calc, Draw and Base (common part of the question because this tag is for problems present in all components of the suite).
I should had been more verbose in my answer (as I had been notified in a PM; I see now that I was wrong thinking it wasn’t necessary).
LibreOffice will deduplicate all images, no matter how you inserted them, when they are the same byte sequences. When writing images, it calculates hash for each of the images, and uses the hash as the name of the image; and then, it only writes one copy of each so-named image.
So - unless you talk about really different images, like PNG and TIFF with same pixels, but still different byte content - the images will be “linked from one source” eventually, even if inserted separately from the same source file, even in different editing sessions, and different document areas (text body, header/footer, different spreadsheet sheets, different slides, whatever).
I agree there is a single copy of image contents. But there is still a dedicated “descriptor” (or whatever it is) per occurrence and this dedicated descriptor prevents my need for a “central management” feature just like paragraph or character styles do for formatting. I had a very specific requirement about margin icons for warning, caveat, note, … paragraphs and I wanted to be able to change easily this icon for all similar paragraphs. I finally ended up with the idea of a list style using a graphical “bullet”. And the multi-level feature in list styles allows for very fancy effects.