optimize all photos on my website for speed

I need someone to go in an optimize the photos on mwy website for speed as they are currently slowing down the website dramatically . I need this projected completed asap as it is affecting my sales . You need to know how to go in an optimize the photos without affecting the overall look of site and still giving good user visuals of photos there are only a few listings so its not a large job to someone with good knowledge of this type of thing im using the shopwired platform for my website .