Now I am building my text/font manager, all based on your library - it's of great help.

I think, your creation would benefit from supporting the lanczos filter for resizing. It's one of the slowest I know (see IrfanView - it's a viewer that supports this filtering mode) but it's awesome in how it manages to keep the picture visually sharp even if your new size is just one pixel bigger. Bicubic blurs mercilessly in such cases.