Decrease White Spaces In Images And Captions

Hi,

Please view image.

http://smartjewelryshopper.com/decrease-empty-spaces.jpg

How do I decrease the white spacings for images with captions as shown in the diagram?

There is 2 portions: Horizontal and the Vertical spaces indicated by the red lines.

This is the reference URL: http://onlinediamondbuyingguide.com/carat/how-weight-affects-pricing/

Paul