Filter for icons of geoimage layers

[GerdP]

I'd like to have a filter which allows to hide some of the camera icons which are rendered for the pictures in all "Geotagged image" layers.
My use case: Since some years I take photos of objects like information guideposts or situations at crossings. For some objects I have three or more sets of photos taken at different times, most show older states. It is difficult to find the most recent set(s) because the icons are all the same.
I'd like to have a control which allows to e.g. show only those images taken in the last threee month or a specific date.
I probably start coding a patch for this on my own but I'd like to suggestions about the design of the control.

Another idea would be to render the icons in different colors depending on the age. No idea if this is easier to implement?