The present invention relates to techniques for modifying electronic images.
Image warping is a method of modifying an image by changing the spatial configuration of portions of the image. A source image can be warped into a destination image according to a specified mapping between the source image plane and the destination image plane.
Computer applications for image editing allow a user to warp an electronic image using an onscreen “brush”, sometimes referred to as a “warping tool”, controlled by an input device such as a mouse. The user can drag the warping tool along a trajectory from one location to another location within the image, thereby defining an envelope. Pixels of the image within the envelope are moved, creating a warping effect. For example, a sticky brush is a tool that moves pixels from the starting point of the envelope to its end. A slipping brush is a tool that moves the pixels from the starting point a distance less than, but proportional to, the length of the trajectory.