Images play an important aspect on our websites; a site without an image is just as good as dull, no one would enjoy browsing through a site whose content lacks of images. In publishing, images tell a story more than words do thus images you see on Google come from different publishers of all sizes – bloggers, media outlets, and stock photo sites – who have embedded these images in their HTML pages.
The giant search engine is able to index image types formatted as BMP, GIF, JPEG, PNG and WebP, as well as SVG. The question is how does Google identify that an image is about coffee and not about tea? When Google’s algorithms index images, they look at the textual content on the page the image was found on to learn more about the image.
Google also takes a look at the page’s title and its body; it can also learn more from the image’s filename, anchor text that points to it, and it’s “alt text”, Google may use computer vision to study more about the image and may also use the caption offered in the image Sitemap if that text also exists on the page.
To assist Google to catalog your images, you should make sure that:
- Google can creep both the HTML page the image is entrenched in, and the image itself
- The image is one of Google’s supported formats: BMP, GIF, JPEG, PNG, WebP or SVG
Moreover, Google commends:
- That the image file name is related to the image’s content
- That the alt attribute of the image describes the image in a human friendly way
- And finally, it also helps if the HTML page’s textual contents as well as the text near the image are related to the image
If you need more information regarding how Google index images, kindly check out the section of Google’s Help Center dedicated to images, read its SEO Starter Guide which has lots of useful content.
Source: https://googlewebmastercentral.blogspot.com/2012/04/1000-words-about-images.html