skip to main content
10.1145/1992896.1992899acmconferencesArticle/Chapter ViewAbstractPublication PagesuccsConference Proceedingsconference-collections
research-article

Simple random generation of smooth connected irregular shapes for cognitive studies

Published: 16 May 2011 Publication History

Abstract

A simple method for generating random smooth connected mildly irregular binary shapes is introduced. It consists of 1) taking the Minkowski sum of a closed linear spline with random vertices and of a disk (in other words, joining consecutive randomly generated points with straight lines drawn with a "large ballpoint pen"); 2) applying Gaussian blur with a large blur radius; and 3) thresholding permissively. With very permissive thresholds and moderately large numbers of seed points, this produces fairly natural-looking "random blobs." One can also generate "cartoonish shadows" and "boldface alphabets" with less permissive thresholds and smaller numbers of seed points.
Rotation invariant families of shapes can be generated by drawing the spline vertices from rotation invariant distributions. Results obtained with the uniform distribution on the disk and the binormal distribution are presented. They are contrasted to those obtained with the uniform distribution on the square. Drawing random points from a binormal distribution gives a collection of shapes that look natural over a wide range of numbers of seed points. The shapes derived with the uniform distributions, however, are more "interesting."
Thresholds close to the most restrictive value yielding an empty shape when there is only one seed point work well. This critical threshold is easy to compute using the drawing software; thresholding more permissively guarantees a nonempty shape.
The most restrictive threshold guaranteeing a connected final shape is analytically estimated using the diameter of the "pen nib" and the Gaussian blur sigma. The various bounds are in agreement.

References

[1]
P. Adamic, V. Babiy, R. Janicki, T. Kakiashvili, W. Koczkodaj, and R. Tadeusiewicz. Pairwise Comparisons and visual perceptions of equal area polygons. Percept. Motor Skill., 108(1):37--42, February 2009.
[2]
T. Auer and M. Held. Heuristics for the generation of random polygons. In F. Fiala, E. Kranakis, and J.-R. Sack, editors, Proc. 8th Canad. Conf. Computat. Geometry, pages 38--44, Ottawa, Canada, Aug. 1996. Carleton University Press.
[3]
G. E. P. Box and M. E. Muller. A note on the generation of random normal deviates. Ann. Math. Stat., 29(2):610--611, 1958.
[4]
E. Bribiesca. Classification and generation of 3D discrete curves. Appl. Math. Sci., 1(57):2805--2825, 2007.
[5]
J. Cristy, K. Bergougnoux, R. Bogart, J. W. Peterson, N. Brown, M. Chiarappa, T. R. Crimmins, T. Edwards, J. Fojtik, F. J. Franklin, M. Friedl, B. Friesenhahn, M. Halle, D. Harr, C. R. Hawks, P. Heckbert, P. Langlo, R. Mabry, C. Mihaila, D. Pensak, C. Racette, W. Radcliffe, G. Randers-Pehrson, P. Raveling, N. Robidoux, L. Rosenthol, K. Shorter, L. R. Skyum, A. R. Smith, E. R. Lyons, M. Still, A. Thyssen, M. Votava, F. Weinhaus, and A. Zimmermann. ImageMagick. Software: http://imagemagick.org. Downloaded Apr. 1, 2011.
[6]
D. H. U. Kochanek and R. H. Bartels. Interpolating splines with local tension, continuity, and bias control. Comput. Graphics, 18:33--41, 1984. SIGGRAPH '84 Proceedings.
[7]
K. Martinez and J. Cupitt. VIPS -- a highly tuned image processing software architecture. In IEEE Int. Conf. on Image Processing, pages 574--577, Genova, Sept. 2005.
[8]
C. Oertel and P. Bock. General shape generation by contouring fractals and applying linear boundary regression. In AIPR '07: Proc. of the 36th Applied Imagery Pattern Recognition Workshop, pages 111--116, Washington, DC, USA, 2007. IEEE Computer Society.
[9]
P. Stelldinger. Image Digitization and its Influence on Shape Properties in Finite Dimensions, volume 312 of Dissertations in Artificial Intelligence. IOS-Press, 2008.
[10]
D. Terranova. Random Shape Generator. Software: http://www.davidterranova.com/random-shape-generator. Downloaded Feb. 22, 2011.
[11]
A. Thyssen. Random Spots of Solid Color. ImageMagick Examples online documentation: http://www.imagemagick.org/Usage/misc/#spots. Downloaded Feb. 21, 2011.
[12]
F. Weinhaus and N. Robidoux. Randomblob ImageMagick script. Software: http://fmwconcepts.com/imagemagick/randomblob/. Downloaded Apr. 9, 2011.

Cited By

View all
  • (2015)A spectral clustering search algorithm for predicting shallow landslide size and locationJournal of Geophysical Research: Earth Surface10.1002/2014JF003137120:2(300-324)Online publication date: 21-Feb-2015

Recommendations

Comments

Information & Contributors

Information

Published In

cover image ACM Conferences
C3S2E '11: Proceedings of The Fourth International C* Conference on Computer Science and Software Engineering
May 2011
162 pages
ISBN:9781450306263
DOI:10.1145/1992896
  • General Chair:
  • Bipin C. Desai,
  • Program Chairs:
  • Alain Abran,
  • Sudhir P. Mudur
Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. Copyrights for components of this work owned by others than ACM must be honored. Abstracting with credit is permitted. To copy otherwise, or republish, to post on servers or to redistribute to lists, requires prior specific permission and/or a fee. Request permissions from [email protected]

Sponsors

Publisher

Association for Computing Machinery

New York, NY, United States

Publication History

Published: 16 May 2011

Permissions

Request permissions for this article.

Check for updates

Author Tags

  1. Gaussian blur
  2. Minkowski sum
  3. connectedness-preserving blur/threshold combination
  4. dilation
  5. effective radius
  6. level sets
  7. random binary shape generation
  8. rotation invariant families of shapes
  9. smooth irregular shapes
  10. thresholding
  11. uniform and binormal random point distributions

Qualifiers

  • Research-article

Conference

C3S2E '11
Sponsor:
  • ACM
  • Concordia University

Acceptance Rates

Overall Acceptance Rate 12 of 42 submissions, 29%

Contributors

Other Metrics

Bibliometrics & Citations

Bibliometrics

Article Metrics

  • Downloads (Last 12 months)6
  • Downloads (Last 6 weeks)1
Reflects downloads up to 13 Jan 2025

Other Metrics

Citations

Cited By

View all
  • (2015)A spectral clustering search algorithm for predicting shallow landslide size and locationJournal of Geophysical Research: Earth Surface10.1002/2014JF003137120:2(300-324)Online publication date: 21-Feb-2015

View Options

Login options

View options

PDF

View or Download as a PDF file.

PDF

eReader

View online with eReader.

eReader

Media

Figures

Other

Tables

Share

Share

Share this Publication link

Share on social media