Questions and postings pertaining to the usage of ImageMagick regardless of the interface. This includes the command-line utilities, as well as the C and C++ APIs. Usage questions are like "How do I use ImageMagick to create drop shadows?".
Your command works fine for me, with IM v6.9.5-3 on Windows 8.1. When the tiff file contains two images, it creates two files image*.png and two files thumb*.png.