Cloudinary offers a wide variety of transformations that enable you to to manipulate images on the fly by using dynamic URLs. Web and mobile developers use these transformations on their images to achieve everything from optimization and responsive delivery to a variety of image improvement manipulations, with a huge collection of cool effects to choose between. One of the more robust transformations applies another image as a displacement map to manipulate your base image in a variety of ways. The displacement mapping algorithm evaluates every pixel in the image map and then displaces the pixels in the base image based on the intensity of the corresponding image map pixels.
Cloudinary offers a wide array of image manipulations and effects to apply to images as part of our image-processing pipeline, helping to ensure that your images fit the graphic design of your website or mobile application. Cloudinary is an open platform, and you can use our APIs, Widgets and UI to build the media management flow that matches your needs.
The value of categorizing all the images in your library cannot be underestimated. Besides the obvious advantage of making your image library searchable and displaying relevant content to your users based on their interests, you can also learn more about your users according to the content they upload, and find out what people care about and look for. However, when dealing with a large volume of images, manually categorizing the images would take up too much time and resources.
Update - April 2016: The add-on described in this post is no longer available since ReKognition terminated their services. However, all features described here are still available via a different and even better add-on by Microsoft. See Facial attribute detection with Microsoft's Face API and the Advanced facial attributes detection add-on documentation.