How Google Images works? Basics

Because nearly one billion images are floating around on the Web, finding the picture you need for your research can be pretty tricky. Google Images helps you manage this difficult feat.

Understanding how Google Images works

Contrary to what you might expect, Google Images has no ability to actually analyze a photograph or other picture on a Web page. Instead, Google Images uses the context of an image to determine the image’s relevance in your search results. That’s right! The picture itself is not considered. The text of the Web page surrounding the image, the content of the alt HTML parameter associated with the image, and (most importantly) the caption of the image are the essential clues Google uses to categorize and sort image search results.

Using contextual analysis, Google Images does a surprisingly good job of understanding what an image depicts. Of course, Google Images can’t always do a perfect job, and if the contextual elements aren’t present — perhaps an image is placed alone on a Web page without any text at all — Google has no way to determine the content of the image.

Google does not consider the filename of an image when analyzing what the image is. So if you have a photo named billclinton.jpg on a page by itself, Google won’t know that the picture is of Bill Clinton.

Accessing the Google Images tool

You have your choice of a number of ways of opening the Google Images application:

  • Type into the Address Bar of your browser and click the Go button (or press the Enter key on your keyboard).

  • If you have installed the Google Toolbar, click the Google button to open the fly-out menu; from the menu, choose Google Links –> Google Images.

  • On the Google home page, click the Images link.

  • On the Google home page, click the More link; when the Google Services and Tools page opens, click the Images icon or link.

Searching for images

On the Google Images home page, you can search for an image by entering a query in the Search box and clicking the Google Search button.

Google Images searches for contextual information about the image, as well as any written content that appears near the image on the Web page; it doesn’t have any way of searching the content of images themselves. For this reason, you may need to finesse your search, framing your image searches with language that might be near your desired pictures.

Be aware that words have more than one meaning. Although this is something to consider in all Google searches, pictures can be a lot more vivid (or inappropriate) than you might be expecting. If you want to filter out inappropriate content, be particularly careful when you choose search terms. For example, a search for the term disney bambi yields G-rated results, but a search for bambi alone might not.

Because Google Images works by coming up with pictures that are nearby the text string you entered, search results can return people and objects not remotely in the search terms. For example, the first image returned by a search for mark anthony julius caesar is an image neither of Mark Anthony nor of Julius Caesar as you might expect, but rather of Cleopatra.

Understanding image results

When you conduct a Google Images search, the search results page returns thumbnails of the images that Google Images found.

Each image on the search results page is captioned with its filename (and file format), the URL for the Web page that contains the image, the size of the image in pixels, and the size of the image file.

From this main image search results page, you can change your SafeSearch settings and access the Advanced Image Search window.

You can also click each image on the search results page. Clicking an image opens an image-specific results page.

Each image-specific results page shows a thumbnail of the image, as well as the Web page containing the image. Technically, the image-specific results page is constructed using HTML frames. The thumbnail is in a top frame, and the Web page containing the image is in a bottom frame. The frames allow you to simultaneously view both the thumbnail of an image and the context in which it appears.

Downloading images

Downloading images from Google Images — or from the pages that contain the images — is easy enough, but before you do so, make sure that you understand the legalities of copyrighted material.

Depending on your computer’s operating system, you can probably drag-and-drop images to your computer. For example, if your computer runs Windows XP, you can drag-and-drop images from the Image Results page to your Windows desktop or to a folder within Windows Explorer.
If you have trouble dragging and dropping the image, right-click the image and choose Save Picture As from the context menu.