If you want to resize a high-resolution bitmap to be a lower size/resolution, at the highest possible quality, the recommended way is simply to resize it on screen to the required dimensions and either Export or Create Bitmap Copy.
Both Export (Ctrl+Shift+E) and Create Bitmap Copy (Ctrl+Shift+C) do not use the screen version, but re-create a higher quality (bicubic sampled) version for export. This is especially noticeable when scaling very large bitmaps down.
The screen display uses simple smoothing and shows aliasing artefacts when scaled much less than half size. The exported or re-created version is much higher quality. This is illustrated when doing screen grabs. It takes a few seconds to create a high quality, small size, re-scaled screen grab to paste into any application. Please search the knowledgebase for 'screen grab' to view additional information on creating screen grabs.