Any images in your web page should be configured correctly.
Understand that Google cannot see images. They can only understand what it is from what you say in the text. They can make an assumption from the relevance of the text around it but you can specifically tell Google what it is.
Again an old techniques was to add the primary keyword to every IMG tag but this is not the way to do things in 2013.
Each picture should have a clear description of what it is.
Firstly you can add something descriptive in the ALT text and also make the file name descriptive.
So if you have a picture of a fig tree for example your HTML code may look something like this
<img src=”fig-tree.jpg” alt=”Large Fig Tree In Fruit”>
This allows Google to fully understand your image.
If you use WordPress you will also have the option to add a caption to the image. This should be targeted at the visitor not the SE. So make the caption interesting
Stunning Fig Tree Outside Our Holiday Apartment At Acapulco Beach
Interesting images and captions will help keep people interested in your web page and keep them on it longer. This is a good thing for SEO. Remember I said Google have the technologies. Well, measuring how long visitors stay on your site, is one of them. This is called bounce rate. The shorter the bounce rate the less interesting or relevant Google will see you page as.
Images have their own search in “Google. Go to the top of Google search page and choose “Images” from the top menu. You can now search just on images. However this is not the only place images will appear. They are also added to the natural SERPs. This is why you should ensure your images are accurately titles and Google will reward you with images amongst the top 10 search results.
These will be linked back to your webpage.
One recent downside is that Google have changed the way they display the images in the SERPs. They used to display basically a thumbnail and you had to click on it to go to the full size image.
However Google now include HD images in the SERPs which means people looking for images specifically don’t need to click-through to your site to see the full resolution picture.
This has caused a dramatic reduction in image click-through to the web pages. However it is still something you must do as part of your overall SEO.