Image warps for artistic perspective manipulation

Abstract

InputResult: Sharply converging lines Result: Weakly converging lines Figure 1: We present a tool for controlling the perspective in photographs by manipulating vanishing points and lines. We can constrain the lines to converge sharply as in a wide-angle image or more weakly as in a telephoto image ( Figure 2). Our perception of the room changes for each result; the former result feels more tightly enclosed and the later feels more spacious. AbstractPainters and illustrators commonly sketch vanishing points and lines to guide the construction of perspective images. We present a tool that gives users the ability to manipulate perspective in photographs using image space controls similar to those used by artists.Our approach computes a 2D warp guided by constraints based on projective geometry. A user annotates an image by marking a number of image space constraints including planar regions of the scene, straight lines, and associated vanishing points. The user can then use the lines, vanishing points, and other point constraints as handles to control the warp. Our system optimizes the warp such that straight lines remain straight, planar regions transform according to a homography, and the entire mapping is as shape-preserving as possible. While the result of this warp is not necessarily an accurate perspective projection of the scene, it is often visually plausible. We demonstrate how this approach can be used to produce a variety of effects, such as changing the perspective composition of a scene, exploring artistic perspectives not realizable with a camera, and matching perspectives of objects from different images so that they appear consistent for compositing.

Content-Aware Rotation

“…For λ L and λ R , our method involves the issue of parameter settings as in other multi-term warping methods [7,6,8]. We find λ L = λ R = 100 work well in various experiments.…”

“…The method in [16] introduces an "as-rigidas-possible" manipulation of shapes or images. The studies in [18,7,6] use the warping strategy to adaptively project wide-angle/panaramic images. Warping has also been adopted in image morphing [9], video stabilization [21], and panorama rectangling [14].…”

Distorted Perspective for the Forward Camera Dolly

“…For 2D images, a method that provides perspective effects based on a camera model prepared in advance [Hall et al 2007] and an imaging method that uses multiple constraints (e.g. line segments and points) [Carroll et al 2010] have been proposed. As a study of exaggerated expressions in 3DCG images, Dorsey et al [1998] classified non-photorealistic types of perspectives and constructed a system for setting the parameters of each perspective.…”

Viewpoint Assessment and Recommendation for Photographing Architectures

“…Guo et al proposed an efficient view manipulation method for cuboid-structured images that enables the generation of novel images with new viewpoints given only a single image as input, with moderate user assistance [14]. Carroll et al proposed an interface that allows users to manipulate perspective in photographs and it can also plausibly simulate moderate changes in perspectives induced by the controls, e.g., vanishing points [6].…”