For quick removal, use the Remove URLs tool to remove images hosted on your site from Google's search results within hours.
For non-emergency image removal
To prevent images from your site appearing in Google's search results, add a robots.txt file to the root of the server that blocks the image. While it takes longer to remove an image from search results than it does to use the Remove URLs tool, it gives you more flexibility and control through the use of wildcards or subpath blocking. It also applies to all search engines, whereas the Remove URLs tool only applies to Google.
For example, if you want Google to exclude the dogs.jpg image that appears on your site at
www.yoursite.com/images/dogs.jpg, add the following to your robots.txt file:
User-agent: Googlebot-Image Disallow: /images/dogs.jpg
The next time Google crawls your site, we'll see this directive and drop your image from our search results.
To remove all the images on your site from our index, place the following robots.txt file in your server root:
User-agent: Googlebot-Image Disallow: /
Additionally, disallow patterns may include "*" to match any sequence of characters, and patterns may end in "$" to indicate the end of a name. To remove all files of a specific file type (for example, to include .jpg but not .gif images), you'd use the following robots.txt entry:
User-agent: Googlebot-Image Disallow: /*.gif$
By specifying Googlebot-Image as the User-agent, the images will be excluded from Google
Images. If you would like to exclude the images from all Google searches (including Google Web
Search and Google Images), specify the Googlebot user agent.
How do I remove images from properties that I don't own?
See the Google Search help documentation on how to remove an image from search results.