Resize pictures in the client end

Ok, I put all my questions all in once now, please bear with me.

The Q is:
When upload a picture, can we resize the picture in the client side
before send to server? Can we even convert pictures to other format on
the client side with in a browser.

Or I have to have a client software to do that.

thx.

resizing images is going to be a server-side action, not a client-side.