Magento product thumbnail, how to set it to be proportional

I wan't to set my product thumbnails in Magento to proportionally fit the frame.

At the moment if I upload a rectangular image, the thumbnail will display the width of the rectangle and will leave the space left as white.

I need it to proportionally zooms in the image until both the width and height is met.

Been looking for extensions that do this, but no luck 开发者_运维问答so far!

Here is a page that will help with the image options http://blog.chapagain.com.np/magento-resize-image/

The option to stop it rendering the white space is:

->keepFrame(FALSE);

You may need to also play with some of the other options to get it to your minimum dimensions. There aren't any options that clip the image, so you'll have to hide the excess image in css with overflow:hidden;