Considering Google smart searching technology (which I will not going to explain in full details) lets see how this affects image visibility on internet and what we can do to improve this even further. But first...
How do you understand your image title, description and keywords?
Many articles are written about good image keywording. While many contributors take this seriously and do the keywording more or less successfully, I figured out that image title and description are underestimated. You can check images on DT and see what I mean. Struggling with keywords take most of our time and sometimes it looks like mission impossible. We get into problems when we need a two or three words phrase. Not common like "red balloon" but more specific like "rear view". It is a term by itself but when DT sorted the words you actually get two separate keywords "rear" and "view". While "rear" may work for your image of naked women seen from her back, "view" doesn't work at all, so it's a bummer. Excuse me if I didn't understand that DT allows some way to enter a phrase but you will correct me if I'm wrong.
Here is some knowledge from my SEO expertise which actually applies to optimization of web pages, it applies on every content on internet.
1. Your title must go strait "to the head". Title explains what is it all about. So, if you have a image of dog title it "Dog" not "Pet" or "Best friend". Google puts some weight on title since it is 2-3 words explanation of what is presented bellow. Title defines content. Title of will be shown on the top of your browser window and as a linked title in Google search engine results page which leads directly to your image preview.
2. Description is special case. While lately Google doesn't put much weight on description when we talk about textual content, images are different story. While Google may find your textual content more interesting and make excerpt of it in results page, Google doesn't understand images at all. But the SEO principles applies too. It is not strictly about image but on web page content. And principle guide us to effective description writing: a) put the main words in front, avoid unnecessary words
Bad: Morning sun shining on the lake
Good: Lake under the morning sunlight
If the main subject is lake then put it in front and explain the rest behind
If title is "Roman soldier" and keywords are roman, soldier, armor, helmet, sword, legionnaire, centurion, clipart, illustration, icon, 3D, man, uniform, warrior, ancient, mantle etc. we can bring in some new words which doesn't fit in keywords for relevancy but gives some new elements to search on
Description: Roman soldier, 3D computer generated design illustrating icon of ancient soldier in standing position holding sword and wearing armor and mantle, on white background.
This description may be a bit overdone but It is a fair example. Note that it gives some more words to the image which cannot stand as a keywords alone. Also consider what I wrote about phrases rear view, top view, low angle etc.
c) keep keyword proximity in description phrases,
Bad: Meeting of five men in white shirts doing business
Good: Business meeting of five men in white shirts
Both of this phrases will be find after "business meeting" input but second one will be more relevant and thus higher in results page
d) make description relevant.
There are descriptions on DT which have details of what is done with the image and other non related things. Remember that Description role is to explain the contents of the image and not other things you did.
Bad : This image shows landscape of lake in Montana, I tweak it a bit in Photoshop to bring up colors. TIFF version available.
Description is not advertisement and no one reads description once the image is found. Description serves as help search engines to find relevant content. Description of image will possibly be shown as and excerpt under title in Google results page. It better contains your main keywords.
Lets get real
Ackleyroadphotos (Christopher Ewing) which you can see on the left. Lets do some case study. A I told before DT is SEO optimized site. In practice this means that Google robots examine and analyze the content of every page and index them properly. When you get to specific image the content is merely the same as it is template. Google doesn't index the content that is repeating, and content on image template is the same for all images on DT. The only difference between pages is image and all data that follows it. DT page dynamically creates image preview page by template inserting image data in proper places so every page is unique. Checking the source of preview page for dove image shows what is going on. I cut out the following tags from page source header. NOTE: due to some blog editor restrictions I cannot use real HTML tags because code is executed so i omitted "<" and ">" characters.
1. TITLE Stock Images: White Dove in Flight 6 /TITLE
This tag defines title of the page. As you see the title of the page is the same as the title of your image. Google stores title as one of the references.
2. META name="description" content="A free flying white dove isolated on a black background."
META name="keywords" content="bird black dove faith feather feathers flight fly flying free freedom graceful holy hope isolated nature peace pigeon pure purity religion soar soaring spirit spiritual white wing wings"
As you see here your keywords and description is inserted in this page. Since other content in page template is mostly repeating Google ignores it, and also it can not "see" the image. Only that is left to index are meta tags which explains what this page is all about.
3. IMG src="https://www.dreamstime.com/white-dove-in-flight-6-thumb1585884.jpg" alt="White Dove In Flight 6 Stock Images" title="White Dove In Flight 6 Stock Images" border="0"...
This tag in source is on a place where image is actually presented. Note that DT use friendly names for images (white-dove-in-flight-6-thumb1585884.jpg) which is relevant to image search, it also correctly uses alt and title tags which explains image itself by putting your image title there. Since it is all in image tag (img) search engine knows it is image, what is the name of the file and its description so it consider that this is subject of an image. Al this tags are indexed accordingly.
Now, you can try to open Google and search for "white dove in flight" then check how Google presented the result. Specially look for result on dreamstime.com domain. I hope it is clear enough. Try to search for your images which you upload here and to other sites and see what happened. Which site jump up for the same image? I can say I am pretty pleased with how it works on DT.
When I say this I must mention few other things. In ranking your site (I mean the site where your image is previewed on DT) Google uses hundreds of parameters to determine the web page position in search results page as with any other page on internet. Between others importances and title, description, keyword set lets name some that affects our image performances too. Age of domain, number of visits, unique visits, bounce rate, page activity, frequency of changes, number of clicks under the site, number of outgoing links etc, etc..
We cannot affect those parameters much but there is one which we can. Incoming links. While DT perfectly set the structure with internal links. Everything possible is linked together: Links to other images while previewing, profile cross connections, favorites, blog articles... This causes Google to rank pages by its importance. Simply and primitively said - every page "earns" points from other pages that links to it. We will not discuss the complex calculation about PageRank divided by outgoing links and recursive maths around it. DT has that set up and we have what we have, the best we can. Every image that we include in our blog article is another link to that image page, and even blog articles are indexed by Google. So sharing the importance inside DT web page is done.
But we can do more to bring more importance here - from outside using referral links. If you have any web site use the referral links from your image preview to bring links to that image. Not that it has only practical reason leading directly to the image advertising it, it has another value of getting higher in Google search results: incoming links from other domain raises your index position. You better have them as many as you can.
Well, fellows, this for sure is a long reading, if you get down to here you may get the picture. You may understand that even your blog can make some advantage to your images. While you presenting others, don't hesitate to put some of your own images. The best thing is if your blog article is relevant to your image.
Never underestimate the image title and image description importance besides keywords, take your time an find the best strategy. And never spam. Did I told you that Google deals with search elements spam and can demote your page? :) And start your own off-page search engine optimization by building external links to your image preview. Also note that results of your actions take time. Googlebot is visiting web sites in regular time intervals and it may take from days to months for content to be analyzed, indexed, saved in database and distributed through thousands of Google data centers.
Thanks everyone for reading, I really appreciate your time. If you find this article useful check the button right of the title.