Area V1 and higher areas in the visual cortex contain many feature extraction engines that serve to build a symbolic image
representation. In this paper we present models of cells that complement a multiscale line and edge extraction. After reviewing
a frontend that comprises Gabor filters (simple cells), bar and grating cells, we introduce a bar cell grouping for completing
occluded curvilinear structures (snakes), as well as a grating cell grouping for coding periodic textures with different complexities.
Keywords Perceptual grouping - cortical cells - snakes - textures