You all know about alt tags.
Foreground images within your site should have clear, concise yet descriptive filenames. Try to avoid filenames which do not relate to the content of the image, such as ‘photo-1.gif’. Instead use filenames which relate to the content within the image. Filenames can also contain keywords for that particular page.
But also having relevant file names of images will increase the likelihood of people being able to find your images
when using tools such as Google Image search.(nomensa)
Nomensa Article SEO tips
dated: September 2009
By Emily Coward
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WebpageSEO tips