As Google search engine becomes more and more sophisticated in picture objects recognition it is becoming more and more important to pay extra attention to image optimization. About a year ago Google updated search page interface with new image search result button. And started to accumulate image specific search queries. Plus Google promoting structured data markup usage and introduced new web master search console to help developers trace and analyze website performance. And that includes image optimization.
Let's start with basic. First, image size. It needs to be as small as possible in weight and ideally exactly fit this image HTML code “height” and “width”, picture might have a title attribute. Second, give your pictures meaningful file names. Third, write metadata inside image file itself, add copyright information. Fourth, use content deliver network CDN when it is possible and even better use several to slit image delivery between multiple hosts. Fifth, check and trace your results.