Trying to scale images using Forms, memory usage still way too high.

Just implemented a way to download images and show them as thumnails in a ListView on one page in my app. I'm using Forms and as much shared code as possible due to trying to develop this app for both iOS and Android.
I've noticed that when the image is downloaded and scaled down with default Forms methods (aspect), the image size used up in the ram memory is still the same as before the scaling. Therefore I now have three small thumbnails, all taking up approximately 10 MB in memory each. This is a huge problem for me and would make it impossible to continue developing using Xamarin and Forms if no workaround is possible.
Any tips would be helpful!