In order to limit the binary size and the memory footprint, all resources are compressed automatically by the Resource Converter of a Platform Package. The resources are loaded into the memory only when they are needed.
All loaded resources remain in memory as long as they are needed. If they are not used anymore from the UI application and if there is enough space available the resources remain within an internal cache of the Graphics Engine. If there is not enough space, unused resources are disposed from the cache automatically.
The Graphics Engine provides bitmap and font caches which can store once decompressed bitmaps and font glyphs for later, so the CPU load is limited. The size of the cache can be limited, so that the memory footprint is reduced. In any case this can be a balancing act when the target system is very limited regarding its resources.