Originally Posted by DPreview

According to their white paper this new format offers compression ratios close to JPEG-2000 but with the computational requirements of JPEG (smaller files with the same image quality). The use of new algorithms are also claimed to reduce the visibility of 'objectionable spatial artifacts' (those mosquito JPEG artifacts).

Originally Posted by Microsoft

Multiple color formats for display or print
Fixed or floating point, high-dynamic-range image encoding
Lossless or high-quality lossy compression
Extremely efficient decoding for multiple resolutions and sub-regions
Minimal overhead for format conversion or transformations during decoding