Amit Shesh

3D-aware image editing for out of bounds photography

Graphics Interface, 2009

: Example "Out of Bounds images" obtained with our software tool. The algorithms presented in thi... more : Example "Out of Bounds images" obtained with our software tool. The algorithms presented in this paper allow a user to easily create such depth-rich images starting from single, conventional two-dimensional photographs and paintings. The careful placement of occlusions and cast shadows is responsible for the strong "pop-out" effect in these images.

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Peek-in-the-Pic: Architectural Scene Navigation from a Single Picture Using Line Drawing Cues

The ability to navigate through the scene captured in a photograph generates much more excitement... more The ability to navigate through the scene captured in a photograph generates much more excitement than merely looking at one. Through our system, SMARTPhoto, we accomplish navigation by utilizing work done in reconstruction of 3D geometry from 2D line drawings. We regard objects traced from a photograph as line drawings, formulate the reconstruction problem as an optimization problem and extend current work done in reconstruction of orthographic line drawings to build navigable models from perspective images. We also provide a basic sketching tool to progressively complete invisible parts of the reconstructed buildings. We use texture synthesis to interactively fill holes created in the original image when reconstructed buildings are removed from it. Minimal manual work, ease of use and interactivity are the salient features of our approach.

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Peek-in-the-Pic: Flying Through Architectural Scenes From a Single Image

Computer Graphics Forum, 2008

Many casually taken ‘tourist’ photographs comprise of architectural objects like houses, building... more Many casually taken ‘tourist’ photographs comprise of architectural objects like houses, buildings, etc. Reconstructing such 3D scenes captured in a single photograph is a very challenging problem. We propose a novel approach to reconstruct such architectural scenes with minimal and simple user interaction, with the goal of providing 3D navigational capability to an image rather than acquiring accurate geometric detail. Our system, Peek-in-the-Pic, is based on a sketch-based geometry reconstruction paradigm. Given an image, the user simply traces out objects from it. Our system regards these as perspective line drawings, automatically completes them and reconstructs geometry from them. We make basic assumptions about the structure of traced objects and provide simple gestures for placing additional constraints. We also provide a simple sketching tool to progressively complete parts of the reconstructed buildings that are not visible in the image and cannot be automatically completed. Finally, we fill holes created in the original image when reconstructed buildings are removed from it, by automatic texture synthesis. Users can spend more time using interactive texture synthesis for further refining the image. Thus, instead of looking at flat images, a user can fly through them after some simple processing. Minimal manual work, ease of use and interactivity are the salient features of our approach.

Efficient and Dynamic Simplification of Line Drawings

Computer Graphics Forum, 2008

In this paper we present a pipeline for rendering dynamic 2D/3D line drawings efficiently. Our ma... more In this paper we present a pipeline for rendering dynamic 2D/3D line drawings efficiently. Our main goal is to create efficient static renditions and coherent animations of line drawings in a setting where lines can be added, deleted and arbitrarily transformed on-the-fly. Such a dynamic setting enables us to handle interactively sketched 2D line data, as well as arbitrarily transformed 3D line data in a unified manner. We evaluate the proximity of screen projected strokes to simplify them while preserving their continuity. We achieve this by using a special data structure that facilitates efficient proximity calculations in a dynamic setting. This on-the-fly proximity evaluation also facilitates generation of appropriate visibility cues to mitigate depth ambiguities and visual clutter for 3D line data. As we perform all these operations using only line data, we can create line drawings from 3D models without any surface information. We demonstrate the effectiveness and applicability of our approach by showing several examples with initial line representations obtained from a variety of sources: 2D and 3D hand-drawn sketches and 3D salient geometry lines obtained from 3D surface representations.

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Sketch-based Segmentation of Scanned Outdoor Environment Models

Sketch Based Interfaces and Modeling, 2005

... Intelligent paint [Ree99], which is a region-based interactive segmentation technique based o... more

Crayon lighting: sketch-guided illumination of models

Computer graphics and interactive techniques in Austalasia and South East Asia, 2007

... Amit Shesh and Baoquan Chen∗ University of MinnesotaTwin Cities ... This tool has been imple... more

SMARTPAPER - An interactive and easy - to - use sketching system

Eurographics, 2004

Hardware Accelerated Motion Blur Generation

Motion blur occurs in photography by the motion of objects during the finite exposure time that t... more Motion blur occurs in photography by the motion of objects during the finite exposure time that the cam- era shutter remains open for to record the image on film. The traditional method of rendering a motion blur with a computer is to render the scene at many discrete time instances in every frame. In this paper, we present an efficient motion blur generation method that leverages modern commodity graphics hard- ware. Our method avoids rendering the entire complex scene many times per frame. It first renders the scene into a texture, next renders the optic flow, created based on object transformation, to a vector field texture. The scene texture is finally efficiently blurred according to the vector field using texture- mapping hardware to do a piecewise iterative line integral convolution. Though our method uses vertex velocities to calculate image pixel velocities, the line integral convolution is performed on an image, mak- ing our method largely independent of scene complexity.

Crayon lighting

Proceedings of the 5th international conference on Computer graphics and interactive techniques in Australia and Southeast Asia - GRAPHITE '07, 2007

... Amit Shesh and Baoquan Chen∗ University of MinnesotaTwin Cities ... This tool has been imple... more

User Interface Design and Realization of a Design-by-Sketches System

This paper describes the user interface design techniques for a design-by-sketches system. The ov... more

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High-level application development for non-computer science majors using image processing

Computers & Graphics, 2012

It is a unique challenge to teach programming and application development to students pursuing an... more It is a unique challenge to teach programming and application development to students pursuing an IT degree other than computer science. Using simple visual computing as a medium to teach programming can be very helpful in such situations as it enables programmes that produce pictures rather than raw text and data. This paper describes a semester-long experience of using image processing as the theme in a course to teach programming and program design to students of information systems. Students progressively built a fairly complete image processing application from scratch in a bottom-up fashion using Java. They first concentrated on using low-level constructs like arrays and implemented several operations on them, and then supplemented their programs with features like a GUI complete with ''undo-redo'' features and capabilities to handle most standard image file formats. Not only did this approach satisfy all the objectives of a typical programming course but also enabled students to develop meaningful applications from scratch with ''standard'' features. Our classroom was composed of a mix of undergraduate and graduate students lacking sufficient programming background. A comparative analysis shows improvement in student performance when using image processing rather than not. With minor variations, our approach can be fit to courses for other majors where programming is considered useful but not critical.

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Peek-in-the-Pic: Flying Through Architectural Scenes From a Single Image*

Computer Graphics Forum, 2008

... in this paper were produced on a Dell desktop system with a 2.6 GHz Pentium Xeon processor an... more

SMARTPAPER: An Interactive and User Friendly Sketching System

Computer Graphics Forum, 2004

This paper describes an interactive sketching system for 3D design/modeling that diverts from the... more This paper describes an interactive sketching system for 3D design/modeling that diverts from the conventional menu and button interfaces of CAD tools. The system, dubbed SMARTPAPER, offers a unified sketching environment that supports direct sketching as well as gestured sketching with more emphasis on the former to encourage natural sketching styles. SMARTPAPER also provides a unified 2D and 3D drawing domain by allowing the user to sketch directly on a 3D model in addition to the usual 2D sketching from scratch. A natural sketching experience is offered by supporting casual sketching consisting of wiggly, discontinuous, overlapping strokes. The system is empowered by an array of seamlessly integrated 2D and 3D features such as 2D sketch cleaning, 3D reconstruction from 2D sketch, 3D transformations, sketching on 3D, and conventional 3D CSG operations like cutting and joining. The key to the success of SMARTPAPER is efficient and robust 3D reconstruction from a single freehand 2D sketch with minimal hints. We have employed and improved Lipson's optimization method, originally designed for offline reconstruction of engineering drawings, in our interactive system by leveraging additional clues obtained by interaction during sketching.

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Use of Tricksters in Gerald Vizenor's Fiction

The present paper aims to present the tricksters presented by the Native American writer Gerald V... more

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