Shadowy and Torn Paper Effect

Take an image of your choice to imagemagick

Note down the size of your image

My image is 250x373.

Now go to view tool bar

Put white in fill color slot, change method to reset, and paint type to color

Activate the arrow by clicking on the image

You should see a white background now.

Go to decorate and put black border of size 10x10

Effect-> 10 spread

Effect-> 3x3 blur or gussian blur

Resize - 250x373! (don’t forget the ‘!’)

Now you have two choices:

Composite the original image as compose-> multiply and overlay for darker border

Or go to enhance- negate and compose-> screen for white border like torn paper.
 

You should see something like this after  using  negate 

Here are the samples:

 Dark Border

White Torn Paper Effect

Love is Blue