Perceptual Organization as a Foundation for

Intelligent Sketch Editing

Eric SaundJames Mahoney

David FleetDaniel LarnerEdward Lank

Palo Alto Research Center

Goal: Intelligent Sketch Editing

Central Problem: Selection

Goal: Simple, easy user actions to select desired image material (e.g. tap, click, crude gesture).

WYPIWYG: What You Perceive is What You Get

Motivation

Prior Domain Knowledge

high

low "paint" editors

domain structureeditors

Choice: What degree of prior domain knowledge?

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Perceptual Organization

•make available generic visual structure

•foundation for domain-specific recognition

Gestalt Rules of Perceptual Organization

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•ClosureWhich dot is on an object?

•Smooth ContinuationWhat are the objects?

•ProximityIdentify the text groups

•Symmetry

•Similarity

•Coherent Motion

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Perceptual Structure in Sketches

The ScanScribe Document Image Editor

I. GUI substrate•convenient encircling gestures•implicit creation of image objects•management of grouping structure

The ScanScribe Document Image Editor

I. GUI substrate•convenient encircling gestures•implicit creation of image objects•management of grouping structure

II. Automatic structure detection•grouping/P.O.

Image/StrokeData

Primitives Groups

prime

composite

Image

PrimeObjects

image processingcontour tracing

thinningjunction detection

line followingcorner detection

shape classification

Extracting Primitives

Perceptual Grouping

analyze localspatial relations

form links

assemble larger structures:

CompositeObjects

C C

C A

Closed_Path

Text_Run

TextLine Art

Curvilinear Continuity

clear ambiguous

potential combinatorial explosion

Curvilinear Closure

smooth-continuation

maximally-turning

Text Layout

Key Problem: Ambiguity

Local evidence is insufficient.

Research problem: effectiveuse of spatially extended context.

Conclusion

Intelligent Sketch Editing

•Easy selection of visually-salient material

•Recognition at the level of Perceptual Organization

•Research-prototype: the ScanScribe image editor

P.O. Level Structuring

Image/StrokeData

Primitives Groups

Line-art and Text

Prime objects can servemultiple roles.

Goal: Intelligent Sketch Editing