Possible performance enhancement on source images

[MrKappa]

Is your feature request related to a problem? Please describe.
I'm always frustrated when I wait for image generation.

Describe the solution you'd like
Reduce the source image to the biggest version required by the loader to avoid computing unnecessary huge images.

Describe the solution you'd like
Automatically reducing the source image to the biggest version required by the loader.

Additional context
Source images are usually huge and bigger than the biggest version required by the project.
I think that working with such huge images could lead to bad performances.
This statement should be verified.

[IlCallo]

This may contribute to reduce the processing time in the server and transferring type from/to it.
Can help to mitigate the self DOS we are launching against ourselves