Natural Search Blog » Image Optimization

Google Image Search - Second Only To Web Search In Size

Ravi — Mon, 20 Jul 2009 00:47:08 +0000

This post is based on the interview between Eric Enge and Peter Linsley, Google’s Product Manager for Image Search. It reveals some interesting aspects of image search which is growing at an accelerated pace.

A recent survey by Hitwise in February 2009 shows Google Image Search as part of the troika of top web properties owned by Google in terms of traffic and revenue.

Peter’s responses to Eric’s questions are summarised as follows:

1) On Page Factors in Optimising Images:
In web search, the bots crawl structured data, have enough signals like title, headings and sub-headings, the body content, the backlinks and anchor text from external sources etc to size up the intent of the page.

An image search does not have such signals to rely upon. The bot can access the image source tag in the html and the alt text describing what the image both of which are the key determinants. The more clarity the alt tag content has, the better the intent conveyed to the crawlers.

Peter affirms that it is a very good practice to have a clear description of what the image is about in the alt text. For users who are vision impaired or who have images turned off, the alt text clearly conveys the message when the mouse is hovered over the image. It is a bonus if the same alt text is found elsewhere on the page content in the form of the title of the image or part of a caption.

From the crawler’s point of view, it can see the image tag and the alt text but these do not say much about the image itself. Naming parts of the image as in Flickr photos also does not help the crawlers as it is not machine readable.

If the title, description and caption of the image is obvious to the user, Peter says this is a huge help in helping his team figure out the text associated with that image and rank it appropriately.

File name is an important attribute that is analysed as it tags on to the image even if it is embedded many times on a page or if it is linked to by other sites. A meaningful file name helps though it is not a very strong signal in the ranking process.

A few issues related to file names are:

A lot of operating systems and web servers do not allow file names in other languages that cannot be represented in ASCII. People cannot use certain types of text when naming the file for the same reason.
Another problem from the human perspecitve is that users cannot do justice when naming the file in their respective language. So the search engines cannot assume that the filename is the best description of the image.

2) The Alt Text:
Peter says that if the image cannot be seen but one can perceive what it looks like, then the alt text should reflect that perception in words. The alt text becomes a replacement for the unseen image.

There is no hard and fast rule on the length of the alt text. It all boils down to how the user would feel about it. The alt text can be as detailed as describing all the details of the image. Peter mentions that having a title, caption and description for the image somewhere on the web page enables the crawlers to treat the image title with the same importance as the equivalent of the HTML page title for that page.

Eric poses a question about the association of caption text with the image by the crawler with an example of Charlie Chaplin dancing in the moonlight with the page content including title tag focused on the same topic. Peter confirms by saying that the association is important to the extent to which the image itself is very important to the page.

The close contextual matching of content to this image is a very strong signal. If the image was removed from that focused page, then it would lose a lot of its value in ranking terms. The key here is to think of it from the user’s perspective. If a user lands on the page on Chaplin and sees a large image of Charlie above the fold, the user can see the relevance straightaway.

If the page has six different sub topics and matching images for each sub topic as in the case of a blog about San Francisco with different posts about the place, Peter says the crawlers are pretty good at figuring out the different topics and the images relevant to each sub topic.

Having a permalink for each of the sub-topics is a big help. A canonical tag on each of the inner pages that contains the detailed post and relevant images also helps the crawlers know the canonical url for the image.

3) Matching An Image And Its Content:
There are a number of ways in which a crawler tries to figure out what an image is about, the content and how it matches the intent of a user search. Machines find it a problem to read what an image is and decipher what it represents.

Peter cites an example of an image showing a shark jumping over the Golden Gate bridge. To humans, the scenario is very obvious. The caption of the image says - Check this out. This does not make any sense to a crawler in figuring out what the image is about unless the pixels of the image are analysed. All the other factors discussed above do add to the confidence level of the image aiding the image search team in trying to figure out the image correctly.

4) Signals In Two Dimensional HTML World Vs Three Dimensional Image World:
Eric mentions the two dimensions of relevance and importance (in the form of backlinks) in the HTML world that are important signals on the page. But in image search, apart from the relevance and importance, the third factor of confidence comes into play.

Peter agrees wholeheartedly and says that unlike external links to a page that are counted as votes in web search, images are seldom linked that way. The search team has to consider the other signals to see if they are talking about the image and appropriately factor them into the algorithm.

5) Web Page Influencing the Ranking of Images:
Peter admits that a web page is certainly a signal in the ranking of images. In a nutshell, from the SEO perspective for image search, all the rules that apply to web serach apply equally in image search also. Being an authority on a certain topic and embellishing the page with unique content all provide signals that help the image as well.

So a page with great content and links from other sites to it and other positivbe external signals associated with it inherently passes on the benefits to images that reside on the page.

For images being above the fold or scattered on a page, Peter says that the user experience is a very important factor. If images add to the relevancy and usefulness of the user experience, then it is a vital factor in conjunction with other signals to return this page in the results. This relevance also proves to users that the results for an image search are very relevant to the user’s query and approved by Google to direct the user to the site.

The image search team try to return the best possible images for queries. It must be remembered that there are lots of sites with competing images that are relevant to the user queries.

6) Difference in Results Between Universal Search and Image Search:
Peter and his team realise that there is a subtle difference in intent of a search query made on web search and specifically on images.google.com for an image search. Users doing a specific image search are definitely looking for image results. It is not the case with universal search though relevant results from different verticals are presented on the SERPs. The intent may differ based on the web property the users perform a search.

7) Combating Spam in Image Search:
The image search inherits all the benefits of the work done by the Google web spam team. All the good practices that apply to web search pretty much apply to image search also.

8.Growth of Image Search and Related Technology:
Peter agrees that image search is a really hot and developing web property with incredible scope for the future. It could end up amassing trillions of images in time to come. It is a huge task indexing and organizing the unique images in the explosively growing image world. Each person’s view of the world is unique and it is reflected in the creation of images.

Peter asks a most interesting question - If someone is interested in seeing only an image, why should the search start with a text query? The solution to this has arrived in the form of the Similar Images launch, a Google Labs project where users can search for images based on existing images. The search is completely visual.

A query like Paris can return results on Paris Hilton, Paris in France, Paris in Texas and the Eiffel Tower in a good search engine. With Similar Images, you can start off with an image and take it as an additional query in your exploration along with the original text query. The image at that point is used as the next query.

With the fall in prices for good quality digital cameras and increasing quality of mobile phone cameras, taking pictures has never been easier and so very affordable. The technological advances in facial recognition software (an aspect of it is used in Google’s Picassa tool) is also helping the image search team in their quest to organize the image world to give it more purpose and a huge reach in the future.

The entire transcript of the interview on Google Image Search that forms the basis of this post makes an interesting read.

Ravi Venkatesan is a senior SEO consultant at Netconcepts, an Auckland search engine optimisation company that offers great SEO services to its clients based in New Zealand and Australia.

Speaking at Dallas WordCamp 2009

Chris — Mon, 22 Jun 2009 17:19:52 +0000

I’m speaking at this year’s WordCamp in Dallas again later this week.

WordCamp is a mini-convention for Wordpress and blogging enthusiasts. Some of the content is Wordpress-centric, but other content is applicable to bloggers in general, such as how to promote your blog and other stuff.

I’ll be speaking on how to use social image sharing services for promotion. Social media sites such as Flickr allow people to publish and share their photos with many other people, and the site is well-constructed in terms of search engine optimization, so posting images there helps get media distributed all over. Using Flickr can help one gain more attention, inbound links, and overall search rankings.

I’ve spoken on using Flickr for promotion and optimization before, and I’ve written on details of image optimization here a number of times.

I’d further recommend blogging to everyone - I first started blogging here on the Natural Search Blog as a guest, after Stephan Spencer invited me, and it eventually changed my overall career path. Be sure to check out Stephan’s articles on blog optimization, btw, since he’s pretty much the top authority out there on the subject.

There’s still a few seats left for Dallas WordCamp - sign up before they’re all gone!

Flickr IS Good for Search Marketing - Despite Naysayers!

Chris — Wed, 14 Jan 2009 17:59:20 +0000

I’ve seen a recent article or two claiming that Flickr can no longer be leveraged for SEO purposes. As frequent readers here know, I’ve long been a proponent of using Flickr, both for its great Web 2.0 features, but also for its marketing/promotional value. I’m sure I’m one of the people that article writer was thinking of when he mentioned hearing recommendations for use from other articles and search marketing conferences.

Flickr can still be a valuable source of internet promotion, and a great tool for the purposes of Image Search Optimization. Read on and I’ll explain.

It is true that Flickr has progressively enacted more and more policing and restrictions against people attempting to use their services for strictly business purposes. We reported last spring on how Flickr now Nofollows most links from users’ pages, and there are lots of cases of people getting their accounts suspended or deleted for breaking the terms of use.

On the surface, it can be difficult to differentiate why Flickr may allow a fan of old advertisements to scan and publish reams of commercial material, while a contemporary company could get their account deleted for displaying similar materials from their current catalog. Both content is commercial, isn’t it?

It may be that the contemporary company’s use is more blatantly intended to push their product into recreational site users’ faces, though.

I would say that in many cases, companies attempting to promote themselves through Flickr are guilty of doing so in a far too heavy-handed manner, and are too aggressively pushing themselves and their products through the medium.

If Flickr is approached from the perspective of engaging with the community in a highly cooperative manner, there’s far less risk of penalization. Engaging with the community of users in an honest way, and in a meaningful way that provides value will not result in banning. There are some great examples of companies and institutions who are doing it right: Ford Motor Company; General Electric; Smithsonian Institution; Concordia University; MTV; Whole Foods; Sony Electronics; Panasonic; Lucasfilm Ltd. (Star Wars); Dell; VH1; Yum! Brands; Nestlé; and more.

(Example of Commercial Use of Flickr)

It’s not hard to do this right, but many people are just too heavy-handed to accomplish it.

As a number of people noticed, even Barack Obama used Flickr effectively in his recent presidential campaign.

Sooooo, let’s just put it to bed: Flickr can still be used well for internet marketing purposes!

There’s undoubtedly some level of hypocrisy in Flickr’s (Yahoo!’s) interpretation and enforcement of their terms of use. Early on, my interpretation of their rules was that they intended to keep people from reselling their image-hosting services, primarily, and to keep them from using it as primary image hosting for large, commercial websites. However, they’ve later enforced a much broader interpretation, going after accounts which use Flickr primarily/only for SEO and marketing purposes.

Yet, Yahoo’s enforcement has been very inconsistent. Thousands upon thousands of people use Flickr for commercial promotion purposes, including: artists, photographers, real estate agents, universities, museums, models, and more. Even non-profit groups use it for marketing and promotion purposes — an identical type of use as that of commercial companies, even if it isn’t a for-profit use.

Further, a number of different parts of Yahoo! itself have leveraged Flickr for SEO and commercial reasons — a case of “do as I say, not as I do.”

Google Photos To Compete With Flickr?

Chris — Tue, 01 Jul 2008 16:00:18 +0000

The Google Operating System blog reports that Google is likely changing the name of their Picasa photo sharing service to “Google Photos”.

A few other features are due to rollout as well, including licensing options, email photo uploads, and tagging of people in pics.

Google’s Picasa Web Albums haven’t competed effectively with Flickr - in fact, I know of a large number of Googlers themselves who are using Flickr instead of their own service. Perhaps with the greater brand-recognition of “Google Photos” they will be able to increase usage. If/when they make the formal change over to the new name, I’d halfway expect them to roll out more features to help propel adoption. The problem is that they’re continuing to play catch-up to Flickr, and as a user it’s not clear to me why I should necessarily switch.

(Interestingly, both Flickr and Picasa use Picnik for image editing/correction, making it somewhat attractive as a potential acquisition target.)

I noted recently that Google introduced the ability for users to add Picasa and Panoramio pics to Maps. It still seems to me that Google should allow users to add their Flickr pics to the maps as well, from a purely user-centric viewpoint. Users don’t care that the two companies are competitors — users just want convenience and cross-platform compatibility.

Is there room for more image sharing services? It seems like there’s a glut of them, and that Flickr is a clear pack leader. In this particular arena, will Google bring any particular value-add or differentiation by continuing to build a competitor service?

New Ranking Methodology for Google Image Search

Chris — Mon, 28 Apr 2008 19:19:42 +0000

The New York Times is reporting on a new research paper about Google’s new image ranking algo which apparently associates an inferred linking relationship between images and uses the PageRank method of iterating ranking values across the graph to come up with final ranking values. This “VisualRank” method was presented in a paper at the International World Wide Web Conference in Beijing this past Thursday, and the process was also reported at Techcrunch.

Google’s advancements in Image Search
could help keep high-value image results
like this coastal pic stay high in the SERPs
for apropos keywords, while making less-
important images rank far lower.

The new methodology is apparently very adept at weeding out less-important and less-useful images from the search results.

I have earlier reported on Google’s research into Supervised Multiclass Labeling (”SML”) which can assist with associating keywords with the actual content found within digital images. See also Search Engine Land’s article on Google’s VisualRank Paper.

Flickr As New YouTube Killer?

Chris — Mon, 17 Mar 2008 16:31:52 +0000

Michael Arrington at Techcrunch reports that video is coming soon to Flickr.

This is great news, and I think it could become an overnight major competitor to YouTube — having both types of media available via one site/service makes for a lot of convenience.

Though, people may not realize that it’s already been possible to a small degree, if you upload an animated GIF to Flickr (see this example where I uploaded an animated sequence of a glider’s movement from Conway’s Game of Life).

Google’s Ranking Advice in Blended Search at SMX West

Chris — Tue, 26 Feb 2008 19:31:38 +0000

Just a quick post here on some simple tips that David Bailey of Google advised in this morning’s session on “The Blended Search Revolution” at the SMX West conference in Santa Clara:

Publish high-quality, well-captioned images;
Have pages which already have good PageRank (use traditional SEO to achieve);
Create a Google Video Sitemap;
Update business listings in Local Business Center;
Submit your feed to Google Product Search;
Create a high-quality company blog;

Flickr Starts Nofollowing

Chris — Thu, 21 Feb 2008 22:42:42 +0000

A couple of my colleagues, Brian Brown and Jeff Muendel, identified that Flickr has begun NOFOLLOWing hyperlinks in their photo profile pages. I’ve confirmed this and have a few more details to add.

As you may recall, I’ve previously recommended using Flickr for image search optimization, partly because it was quite beneficial for building some PageRank, and I’ve also delivered a presentation about this same concept at a number of SES conferences during the past couple of years. (As you may know, getting sites with good PageRank to link to your pages helps to grow your own site’s rankings in search results in Google and other search engines. “NOFOLLOW” is a parameter that search engines developed to allow webmasters to specify links which should NOT confer PageRank — they did this as a means of reducing incentives for unethical or over-aggressive people to spam links through blogs, comments and other sites and interfaces.)

It’s important to note that Flickr continues to be beneficial as part of a search marketing program even if they have revoked their “link love”. There’s large amounts of usage inside Flickr, and those users can click through to your site. Also, the photo profile pages are loved by Google and Yahoo, so the pages get indexed and searchers click through from the search engines to your photo pages and then can still click through to your site. Referral traffic from Flickr can be significant, depending on the type of photos you have and how well you’ve optimized the profile pages.

Jeff noted that Flickr has yet to NOFOLLOW links on Set and Collection descriptions. I also notice that links on your user Profile pages still confer PageRank, too. (You can see this on my Flickr profile page.) I don’t believe any of those pages are quite worth as much for PageRank as the profile pages themselves, but this info may be worthwhile in terms of your Flickr strategy, ongoing. I believe that the best strategy is to focus on good quality content and honest tagging and labeling of the photo pages themselves, though — don’t focus on PageRank so much as doing good quality content and deriving clicks over to your main site — an indirect marketing strategy, in effect.

I would expect that Flickr will probably circle around and revoke NOFOLLOW links on these remaining pages which don’t yet sport the protocol.

Also note: Flickr has rules in their terms and conditions against commercial use of their service. This is the most confounding aspect of understanding Flickr for potential marketing benefit. Flickr does not really define out what their acceptable use is, versus what isn’t. In actual practice, there are loads of people who have been using Flickr for advertising their business, and have been doing so for years. I can point to photographers, models, real estate agents, art galleries and many others who flagrantly are using the service to advertise and drive click-throughs to their main ecom sites. I’d previously interpreted that anti-commercial-use clause as intending to keep people from using Flickr as an image hosting platform, and turning around and charging others for hosting their content. However, Flickr does sometimes delete user accounts for just advertising their products. You should take this into account, in my opinion, and try to be very indirect in advertising your items. Photos which look like catalog photos, with backgrounds clipped out in Photoshop, and linked directly to online catalog sales pages may be more prone to getting penalized/deleted. More “natural-looking” photos are less likely to get dinged, and avoid adding commercially-oriented pics to Group photo album sets. I’ll likely write a commentary about Flickr’s inconsistent application of their anti-commercial clause in a future article.

Google Hiding Content Behind an Image on their SERPs

Chris — Mon, 19 Nov 2007 20:57:55 +0000

Tamar Weinberg at Search Engine Roundtable reports that in a Google Groups forum, a Webmaster Central team member stated that you could use something like the z-index attribute in DHTML styles to hide text or links behind an image, so long as the text/link being hidden is what’s represented in the image.

I think it’s a good thing that they do allow this sort of use, because it appears to me that they’re doing this very thing on their own search results pages! If you refresh a search page, you can see what they’re hiding under their own logo:

(click to enlarge)

…a text link pointing to their homepage.

Now, the interesting question I’d have for the Google team about this would be: this is straightforward if the image itself contains text, but what would be allowable if the image doesn’t contain text, but say, an image of a lion? There’s many different ways to express what that lion is from “lion” to “tawny, golden-furred lion king”.

Or, should we be assuming that images that are written over text and links are only allowable when the image contains text?

The Google Webmaster Tools contributor states that you could be using image’s ALT and TITLE attributes to essentially do the same thing. This is sorta funny, because one could say the same thing of Google’s use of this on their own page — why are they doing it?

One immediately wonders how Google polices this, since they’re apparently not frowning upon pages drawing images over text/links in all cases. They can detect text written over images, but would they have every instance checked by a human? Or, are they using optical character recognition algos to automatically check the text within images against the text being hidden?

In any case, the fact that Google is doing this on their own site could be taken as more confirmation that they don’t consider the technique to be bad in of itself — as long as the practice is conservative and the text/link just describes the text content within the image.

Search Engine Strategies Chicago 2007

Chris — Fri, 16 Nov 2007 17:57:18 +0000

I’ll be speaking at the upcoming Search Engine Strategies (SES) Conference in Chicago during the first week of December.

Seth Godin, author of Permission Marketing and multiple other books will be one of the keynote speakers at the conference, which is way cool — probably well worth hearing.

I’m travelling back and forth in the next few weeks, so I may only be present at the conference the same day as when I’m speaking. If you’re interested in speaking with me that day, hang around after the panel session or drop me a note in advance.