If I start a project that includes still photos in 1080, and export a movie in 1080, everything's fine. But when I drop the output size to 720 or 320, the image files look blurry. The video still looks fine. What I noticed:
* It doesn't matter what type of container I export to (I've tried .wmv, .mov, and .mp4)
* It doesn't matter how large the image file was, nor what type (e.g., .jpg, .png, .psd,. tif)
* The video player doesn't appear to be expanding a sub-1080 size to fill a 1080 screen.
* It doesn't matter whether or not I change my movie settings from 1080 to the size I'm exporting to, or simply change the output size at the export stage.