If you have an image with a HiDPI variant (filename with @2x modifier) and you specify the desired dimensions for the image in the constructor, that image will be loaded at half size on a HiDPI screen.

This is due to a mismatch for how the desired dimensions are managed when a scaled version of the image is loaded.

Run the attached program ThumbnailDPITest on a Mac with retina screen, or a high resolution Windows 8.1 or Windows 10 device to see that the high resolution "thumbnail" (labeled "High") is half the size of the thumbnail created from the image with no HiDPI variaent (labeled "Only"). If you see an image labeled "Low", then you are not running on a high-DPI screen.