Cannot seem to reduce the size of my picture

Hello,

I’ve added a professionally done mugshot to my website. I love the picture, and have it in place as my header. However, I cannot seem to scale the picture down in a proportionate manner. I’ve tried a couple of different photo editing programs with no luck. I’m using theme Twenty Eleven.

I would like my picture to appear on the screen to be about the size of a playing card. No matter how small I make it (I’ve gone to 120×120), it just won’t change.

Any ideas?

Thank you!

Jim