Tracing the outline of an image

Hi,

I've been reading these forums a lot, and decided to make my first post today! I've come across a problem statement that I cannot find on these forums.

Situation :

I will have a page which has some text and may have images. If there are images, I need to draw an outline around the image (does not have to be pixel perfect, just needs to cover the image. However, the text will be wrapped around the image with a gap of around 20-40 pixels, so I need the outline to be within that range.

I am not sure how implementable this is, considering the tool has no prior idea of what image it will be, what shape, size, etc.

(The software I am using has a feature which allows us to plot points around these images with left mouse button, and it connects each point together, so you can effectly "draw" a polygon outline. Hence, this code will have to simply plot left mouse button clicks around the image).

Can someone experienced please help me understand if this is even possible? If so, how?

Thank you in Advance!
Sainath