Gimp resource usage challenges

Whilst Gimp has been great for the NZ Rail Maps mosaics, one of its challenges has been with the layer group feature. This feature unfortunately does a lot more than just organise layers in the layer list. Apparently it adds extra stuff that you may not need.

From my experience I have found the layer groups add significant resource usage, adding in the case of a particular project that was 16 GB, adding about 3 GB of file size for no apparent reason, and when doing a layer crop and export, massively increasing the time to do the crop, export and uncrop. The file save operations from experience have also been very slow.

I now use layer groups only to perform very basic operations, mainly for the grids for layer segmenting, which is only because I can duplicate the grids layers with one click, since you can’t select multiple layers for duplicating but you can select a layer group and duplicate that.

It is a great pity as some of these mosaic projects have dozens of layers and I just have to put up with scrolling through a massive layer list to get to the ones I want, but it seems whatever Gimp is trying to achieve was not designed with the intention of allowing a simple reorganisation of the layers in a project with a large number of them.