How Google Index ImagesGoogle Images is one of the best and an easy way to search for images, photos and pictures of all types and sizesfrom all over the World Wide Web.Every on using Google images for image search, but most of the users don’t know how it works and how Googleknow that the images in SERP are the same what we are searching for.The images shown in search results came from publishers like bloggers, pictures on web pages, stock photo sites,which are embedded in HTML pages. Google can index image types formatted as BMP, GIF, JPEG, PNG and WebP,as well as SVG.When Google algorithms index images, it searches for contextual information about the image, as well as anywritten content that appears near the image on the web page. Also it looks for page title, body, image file name,anchor text points to the image and image’s ALT text.To help Google to index the images, make sure that the image file name should be related to image and ALT tag andthe content near the image is related to the image. Google can index the images of all sizes; there is no size limitwith Google.
Image SitemapsImage Sitemaps help Google to know more about new images and also help Google to learn what the images areabout in web page.Image sitemap allow you to give information about important images on your site. You can include a title, caption,geographic location (where the image was taken) and license information. This information helps Google withmuch needed information about the content of images.For each URL you list in your Sitemap, add additional information about important images on that page. Thefollowing example shows a Sitemap entry for the URL http://example.com/sample.html, which contains twoimages. (You can list up to 1,000 images for each page.)
Safe Search filterNo one wants to include adult content in their search results, preferably if others or kids using the same computer orlaptop. For those users, Google Safe Search filter is available to control their search results. From this main imagesearch results page, you can change your Safe Search settings to prevent adult content appearing in your searchresults. Downloading imagesDownloading images is from Google images is easy enough, you can drag and drop the images on to your desktop orright-click the image and choose Save Image As from the menu. But before downloading images take care of legaland copy right issues.Source: http://googlewebmastercentral.blogspot.in/2012/04/1000-words-about-images.html