A CR2 file is a raw image file format captured by Canon digital cameras. Like most Canon formats, a CR2 file is based on TIFF specifications. Therefore, CR2 files are large, uncompressed, and offer high-quality images. Today, just a handful of programs such as UFRaw and IrfanView provide native support for CR2 files. Microsoft Windows users can also natively view CR2 files, although after installing Canon RAW Codec Software or Camera Codec Pack.
PNG (Portable Network Graphics) is a raster image file format released in 1996 as a replacement for JPEG. That said, PNG uses lossless compression that gives it a small file size while still maintaining the original image quality. Today, PNG format is widely used to share image graphics over the internet and is supported by programs like Paintshop Pro, Adobe Photoshop, Microsoft Paint, Apple’s Preview, etc.