Searching the Internet used to be a text-only affair. Searching for a photograph, for example, meant entering words into a text box to describe the image and hoping one of the results was a good visual match. With advances in search technology, however, it is now possible to search for images using other images, sometimes known as a reverse image search. Image searching can be used to identify an unknown photograph, check for other sites using the same image or find photos, drawings or paintings similar to your original image. You can even use image searching to help you find a shirt to match your shoes.
Basic Image Search Techniques
You need an image file to begin your image search. The image can be a photograph, pie chart, painting, drawing, cartoon or any other visual item in standard image format, such as JPG, GIF, PNG, BMP or TIFF. If you're using an image from the Web, you can drag and drop the picture into most image search tools or copy and paste the image URL into the search box. You can also search on image files from your local system with the search tool's "upload" function. Some search tools offer browser extensions that allow you to right-click an image to launch a search.
Image Search Tools
Google Images houses an index of billions of image files from around the Internet. Google's system creates an electronic "fingerprint" of each image based on lines, textures and features in the picture. It will quickly find files with an identical fingerprint. The Google Image search results will display other sites that contain the identical image to your input file. Even pictures that have been slightly modified, such as a photograph with text added or one that has been reformatted, will be recognized by the search system. Google Images also returns pictures that are similar in appearance to your original image, based on a general match of colors and shapes.
Tineye is another reverse image search tool with functions similar to Google Images. Since Tineye maintains a different index of image files than Google, it's worth trying a search at both sites.
Uses of Image Search
As a photographer or visual artist, you can use reverse image searching to protect your intellectual property. Searching your own images will identify other sites using your materials; if they are doing so without your permission, you can ask the site to remove the image or provide compensation for its use. You can also use image searching to identify an unknown image. The list of sites that contain the same image often include identifying information about the picture or can help you find a high resolution version of an image. A third common use is to find images similar to your original file when you want an alternative to your current image or additional images to match a particular color scheme or topic.
Image Shopping Apps
You can download apps to your phone or tablet that specialize in image searches for shopping. Take a picture of an item you like, such as a shirt or shoes, and the apps will compare the image to other shopping items. You can use these tools to identify an unknown pocketbook, shop for pants similar to the ones you photographed, find a tie to match your suit jacket or suggest color-coordinated items to create your ensemble. Popular visual shopping apps include ASAP54, Pounce and Fashionfreax.