WMS: select image file format

Usually WMS Servers are providing their maps in different image formats to choose from, e.g. JPEG, PNG, TIFF.

JPEG images are usually much less in file size than PNG or TIFF (sometimes just about 1/10th !), so a map with JPEG images is loaded 10 times quicker compared to loading PNG/TIFF images.

On the other hand PNG/TIFF images could provide better optical quality compared to compressed JPEG images.

So it would be great to choose the image file format in the settings dialogue of a WMS server. Providing the the user to choose between quicker map loads or better image qualitys.