The Animated Portable Network Graphics (APNG) file format is an extension to the Portable Network Graphics (PNG) specification. It allows for animated PNG files that work similarly to animated GIF files, while supporting 24-bit images and 8-bit transparency not available for GIFs. It also retains backward compatibility with non-animated PNG files.
EMZ is a file extension for a compressed graphics file used by the Microsoft Office Suite and Visio. Stands for Enhanced Metafile-Zipped. Contains an EMF (Enhanced MetaFile) image file that has been compressed using GZIP compression.