indyank - 7:24 am on Aug 23, 2012 (gmt 0)
I'd love to have my images indexed, as long as the page they are associated with is my image attachment page, and not just the image URL all by itself. Having Google index from an image site-map, wouldn't that result in the image URL's being the ones used? Meaning... a Google visitor comes to the *.jpg url, where there is no HTML at all?
Google always shows a referring html page as the source for the image and not the direct image. If you don't have a referring html page on your site or if you have added "noimageindex" to such pages Google would ignore them as referring pages but you will run the risk of they (google) crediting some other scraper site who give your images a referral html page on their domain by directly linking to the images hosted on your server!
Google will still show the large images in their index but the referral pages will be those of the scrapers and when you land on those pages after clicking close button of the image, people will not find any such image on the landing page as you would have restricted display on foreign domains (excluding google images) using .htaccess. Google is very selfish here as they don't bother about scraping or user's bad experience on the landing page as long as they find a referral page for the image.They will always show every image in their index. So never go by the assumption that your large images are out of their index. The fact is they are only crediting them to wrong sources.
Google images is clearly a case where google act as pure scrapers and don't care about who owns the images. May be, they would have felt that we are already showing the full image as an overlay by scraping it and why do you (their user) bother visiting the landing page by clicking the close button.
This is exactly what happened in the example scenario that I had explained above. But the only difference is I had earlier added only "noindex" meta tag to the image attachment pages and not "noimageindex". I am guessing google is using "noindex" meta tag as a directive for both Google search and google image search. So they have credited the scrapers pages as referral pages. I then went on to remove "noindex" meta tag on all those image attachment pages and instead used canonical tag to specify the parent page url as the canonical link. I am not yet sure on how this will work for google images.
Anyone else has any other ideas on how to handle this?