pngcheck
Print detailed information about and verify PNG, JNG, and MNG files.
TLDR
Print a summary for an image (width, height, and color depth)
$ pngcheck [image.png]
Print information for an image with [c]olorized output
$ pngcheck -c [image.png]
Print [v]erbose information for an image
$ pngcheck -cvt [image.png]
Receive an image from stdin and display detailed information
$ cat [path/to/image.png] | pngcheck -cvt
[s]earch for PNGs within a specific file and display information about them
$ pngcheck -s [image.png]
Search for PNGs within another file and e[x]tract them
$ pngcheck -x [image.png]