User-guided Image Editing using Radial Basis Functions

Abstract

Good image editing tools that modify colors of specified image regions or deform the depicted objects have always been an important part of graphics editors. Manual approaches to this task are too time-consuming, while fully automatic methods are not robust enough. Thus, the ideal editing method should include a combination of manual and automated components. This thesis shows that radial basis functions provide a suitable “engine” for two common image editing problems, where interactivity requires both reasonable performance and fast training.

There are many freeform image deformation methods to be used, each having advantages and disadvantages. This thesis explores the use of radial basis functions for freeform image deformation and compares it to a standard approach that uses B-spline warping.

Edit propagation is a promising user-guided color editing technique, which, instead of requiring precise selection of the region being edited, accepts color edits as a few brush strokes over an image region and then propagates these edits to the regions with similar appearance. This thesis focuses on an approach to edit propagation, which considers user input as an incomplete set of values of an intended edit function. The approach interpolates between the user input values using radial basis functions to find the edit function for the whole image.

While the existing approach applies the user-specified edits to all the regions with similar colors, this thesis presents an extension that propagates the edits more selectively. In addition to color information of each image point, it also takes the surrounding texture into account and better distinguishes different objects, giving the algorithm more information about the user-specified region and making the edit propagation more precise.