Resolution-Independent Meshes of Superpixels
Abstract
The over-segmentation into superpixels is an important pre-processing step to smartly compress the input size and speed up higher level tasks. A superpixel was traditionally considered as a small cluster of square-based pixels that have similar color intensities and are closely located to each other. In this discrete model the boundaries of superpixels often have irregular zigzags consisting of horizontal or vertical edges from a given pixel grid. However digital images represent a continuous world, hence the following continuous model in the resolution-independent formulation can be more suitable for the reconstruction problem.
Instead of uniting squares in a grid, a resolution-independent superpixel is defined as a polygon that has straight edges with any possible slope at subpixel resolution. The harder continuous version of the over-segmentation problem is to split an image into polygons and find a best (say, constant) color of each polygon so that the resulting colored mesh well approximates the given image. Such a mesh of polygons can be rendered at any higher resolution with all edges kept straight.
We propose a fast conversion of any traditional superpixels into polygons and guarantees that their straight edges do not intersect. The meshes based on the superpixels SEEDS (Superpixels Extracted via Energy-Driven Sampling) and SLIC (Simple Linear Iterative Clustering) are compared with past meshes based on the Line Segment Detector. The experiments on the Berkeley Segmentation Database confirm that the new superpixels have more compact shapes than pixel-based superpixels.
Notes
Acknowledgments
The work has been supported by the EPSRC grant “Application-driven Topological Data Analysis” (2018-2023), EP/R018472/1.
Supplementary material
References
- 1.Achanta, R., Shaji, A., Smith, K., Lucchi, A., Fua, P., Süsstrunk, S.: Slic superpixels compared to state-of-the-art superpixel methods. T-PAMI 34(11), 2274–2282 (2012)CrossRefGoogle Scholar
- 2.Arbelaez, P., Maire, M., Fowlkes, C., Malik, J.: Contour detection and hierarchical image segmentation. Trans. PAMI 33, 898–916 (2011)CrossRefGoogle Scholar
- 3.Van de Bergh, M., Boix, X., Roig, G., Van Gool, L.: Seeds: superpixels extracted via energy-driven sampling. Int. J. Comput. Vision 111, 298–314 (2015)MathSciNetCrossRefGoogle Scholar
- 4.Duan, L., Lafarge, F.: Image partitioning into convex polygons. In: Proceedings of CVPR (Computer Vision and Pattern Recognition), pp. 3119–3127 (2015)Google Scholar
- 5.Felzenszwalb, P., Huttenlocher, D.: Efficient graph-based image segmentation. Int. J. Comput. Vision 59, 167–181 (2004)CrossRefGoogle Scholar
- 6.Forsythe, J., Kurlin, V.: Convex constrained meshes for superpixel segmentations of images. J. Electron. Imaging 26(6), 061609 (2017)CrossRefGoogle Scholar
- 7.Forsythe, J., Kurlin, V., Fitzgibbon, A.: Resolution-independent superpixels based on convex constrained meshes. In: Proceedings of ISVC (2016)Google Scholar
- 8.Von Gioi, R.G., Jakubowicz, J., Morel, J.M., Randall, G.: LSD: a line segment detector. Image Process. Line 2, 35–55 (2012)CrossRefGoogle Scholar
- 9.Kurlin, V., Harvey, D.: Superpixels optimized by color and shape. In: Pelillo, M., Hancock, E. (eds.) EMMCVPR 2017. LNCS, vol. 10746, pp. 297–311. Springer, Cham (2018). https://doi.org/10.1007/978-3-319-78199-0_20CrossRefGoogle Scholar
- 10.Kurlin, V., Muszynski, G.: A persistence-based approach to automatic detection of line segments in images. In: Proceedings of CTIC, pp. 137–150 (2019)Google Scholar
- 11.Levinshtein, A., Stere, A., Kutulakos, K., Fleet, D., Siddiqi, K.: Turbopixels: fast superpixels using geometric flows. Trans. PAMI 31, 2290–2297 (2009)CrossRefGoogle Scholar
- 12.Li, Z., Chen, J.: Superpixel segmentation using linear spectral clustering. In: Proceedings of CVPR, pp. 1356–1363 (2015)Google Scholar
- 13.Liu, M.Y., Tuzel, O., Ramalingam, S., Chellappa, R.: Entropy rate superpixel segmentation. In: Proceedings of CVPR, pp. 2097–2104 (2011)Google Scholar
- 14.Luengo, I., Basham, M., French, A.: Smurfs: Superpixels from multi-scale refinement of super-regions. In: Proceedings of BMVC (2016)Google Scholar
- 15.Moore, A., Prince, S., Warrell, J.: Lattice cut - constructing superpixels using layer constraints. In: Proceedings of CVPR, pp. 2117–2124 (2010)Google Scholar
- 16.Shi, J., Malik, J.: Normalized cuts and image segmentation. Trans. PAMI 22, 888–905 (2000)CrossRefGoogle Scholar
- 17.Veksler, O., Boykov, Y., Mehrani, P.: Superpixels and supervoxels in an energy optimization framework. In: Proceedings of ECCV, pp. 211–224 (2010)Google Scholar
- 18.Viola, F., Fitzgibbon, A., Cipolla, R.: A unifying resolution-independent formulation for early vision. In: Proceedings of CVPR, pp. 494–501 (2012)Google Scholar
- 19.Yao, J., Boben, M., Fidler, S., Urtasun, R.: Real-time coarse-to-fine topologically preserving segmentation. In: Proceedings of CVPR, pp. 216–225 (2015)Google Scholar
- 20.Zhang, Y., Hartley, R., Mashford, J., Burn, S.: Superpixels via pseudo-boolean optimization. In: Proceedings of ICCV, pp. 211–224 (2011)Google Scholar