Google image search engine seems to be the finer option, both for people who are looking for images, wallpapers and graphics as well as the business managers who are interested in promoting their sites and increasing their traffic shares through optimizing their images and then hoping that a lot of clicks would be made on their pictures which have been previously picked by Google.

By optimizing your web images properly like adding title or Alt attributes to them and assigning the files to search engine friendly names, after some time you would notice that the hot pictures would drive a lot of visits to your website, derived through queries performed by people who are using Google image section on a daily basis.

Google image search is different from Yahoo and Bing. When you click an image result in Google, the site or article related of that image will shown automatically. While Yahoo and Bing shows plainly the image.
If I were to choose, I'll choose Bing, for its more easy.

Thanks for info on image search, it was helpful to me also, keep up the good work.