Image search, by one definition, is query results, accompanied by thumbnail graphics and supplanted by contextual information, that best match users’ search queries. Such information can be generated and submitted by the image creator, by site owner where the image resides, or by 3rd party reviewers.
The images you see in Google’s search results come from publishers of all sizes — bloggers, media outlets, stock photo sites — who have embedded these images in their HTML pages. Google can index image types formatted as BMP, GIF, JPEG, PNG and WebP, as well as SVG. But how does Google know that the images are about coffee and not about tea? When their algorithms index images, they look at the textual content on the page the image was found on to learn more about the image. They also look at the page’s title and its body; they might also learn more from the image’s filename, anchor text that points to it, and its “alt text;” they may use computer vision to learn more about the image and may also use the caption provided in the Image Sitemap if that text also exists on the page. To help Google index your images, make sure that:
- Google can crawl both the HTML page the image is embedded in, and the image itself;
- the image is in one of their supported formats: BMP, GIF, JPEG, PNG, WebP or SVG.
Additionally, we recommend:
- that the image filename is related to the image’s content;
- that the alt attribute of the image describes the image in a human-friendly way;
- It also helps if the HTML page’s textual contents as well as the text near the image are related to the image.
- Title for Image – Add a suitable descriptive Title for images. Include your keywords in the Title as well.
- Long Desc Attribute – If the image is extremely important and has got some text in it,
- Get Links – Get a few links that points directly to the image itself.
- Link Out – If possible use that image to link out to another page about the image
- Enhanced Image Search – Log in to your Google Webmaster Tools account and activate Enhanced Image Search feature.
- Ranking of the Page – Google image search also considers the ranking of the parent or the linking page.
Places where image search results appear, and are indexable into general search engines’ contextual results, include:
- Major search engines – either within contextual search results or vertical image search
- Photo sharing sites (Flickr, Webshots, PBase, Fotki)
- Social image sharing sites (MySpace, Facebook)
Resource Articles for Google Image Search –