GrabCutInteractive Foreground Extraction

Carsten Rother – Vladimir Kolmogorov – Andrew Blake – Michel Gangnet

GrabCut – Patchworks – Blender Three complementary Tools

GrabCut

Patchworks

Compose

The Goal

User friendly tool for extracting objects in images

Basic Idea

GrabCut - better Quality in less Time

User Input

Result

Magic Wand Magnetic Lasso GrabCut

Colour Contrast Colour & Contrast

How does it work?

Energy minimization based on a novel “MinCut” algorithm

Foreground &Background

Background

Foreground

Background

Colour Space Colour Space

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User Interface

User Input

User Edit

Result

Rectangle Lasso First Result

Brushes Magnetic Lasso

Energy Minimization

User Edit: Fore- and Background brush

User Interface

Evaluation – Moderately Difficult Images

Initially 100% correct Initially 83% correctInitially 91% correct

GrabCut is superior to Magnetic Lasso if more than 50% of the initial boundary is correct

FirstUser Input

FirstResult

FinalResult

Evaluation - Difficult Images

Camouflage &

Low ContrastAmbiguous colours Thin structure

Initially 75% correct Initially 45% correct Initially 5% correct

GrabCut is superior to Magnetic Lasso if more than 50% of the initial boundary is correct

First User Input

InitialResult

Hard & Soft Extraction

Hard Extraction Soft ExtractionInput

Alpha Matting: Boundary pixels are a combination of Foregroundand Background

Basic IdeaRegularized Transition

“Skin”-Colour Profile

GrabCut

Foreground Mixed Background

Energy minimization with regularization

Soft Extraction Comparison

Input

Bayes Matte

Research

Knockout 2

Photoshop Plug InGrabCut

Comparison

GrabCut - better Quality in less Time

Magic Wand

Photoshop 7

Magnetic Lasso

Photoshop 7

Knockout 2

Photoshop Plug-In

BJ-GraphCut

Research

GrabCut

Application – Home UsersEdit your holiday photos

Application – Home UsersDigital Photomontage

Application – Home UsersDigital Photomontage

Application – Home UsersSell objects on eBay

Application – ProfessionalsAdvertisement

Summary

• GrabCut is a user friendly method for extracting objects in images

• Two major steps - Hard & Soft extraction

• For moderately difficult images GrabCut gives better Quality in less Time

• GrabCut will be presented at SIGGRAPH ‘04

Future Ideas

Fully automatic system using object recognition

GrabCut Foreground

FaceRecognition

Carsten Rother

GrabCut Team

Andrew BlakeVladimir Kolmogorov