The Image Decompose node (a beta node) requires the first 2 output sockets to be connected, before it produces any output. The docs mention this: http://nikitron.cc.ua/sverch/html/nodes/beta/image_decompose.html
I wrote this node and admit that this requirement is not the most intuitive, and should probably be revised.
But regarding the Image Node (in Generators), if you open the System Console and see the output of Sverchok you'll get an error, which hints at the problem. A bug.
File "C:\Users\....\sverchok\nodes\generator\image.py", line 112, in process
if 'edgs' in self.outputs and len(self.outputs['edgs'].is_linked) > 0:
Node Image had exception object of type 'bool' has no len()
i'll file a sverchok bug report about that -- this is fixed in the next update.