Lecture04_HeegerBergen.ppt

Pyramid-Based Texture Analysis / Synthesis Presented By : Keren Kahanov Texture Synthesis Generation of much texture as desired so that any object can be covered Input texture Output size Output texture The output texture is synthesized image that match the texture appearance of the given digitized image General Techniques Texture mapping – repeating the texture Can lead to unacceptable artifacts in visible seams , visible repetition Distortion in map to 3-D – often no natural map from planar texture image to the geometry/ topology of the surface. (There are some partial solutions , but no universal solution for mapping an image onto arbitrarily shaped surface.) General Techniques (cont.) Create (paint) textures by hand directly onto the 3-d surface model Very labor intensive Requires considerable artistic skills Computer-synthesized textures as much texture can generated as needed Some of the synthesis techniques produce textures that tile seamlessly. Synthetic textures The distortion problem has been solved in two different ways: Some techniques work by synthesizing texture directly on the object surface. The second solution is to use solid textures (no mapping no distortion) Heeger Bergen Pyramid-Based Texture Analysis / Synthesis Our lecture today A technique for synthesizing an image (or solid texture) that matches the appearance of a given texture sample. The output image (at any size) looks like the original image in its color and texture properties. The texture is synthesized so that it tiles seamlessly. Heeger Bergen (cont.) First order statistics (histograms) Focuses on the synthesis of stochastic textures deterministic textures: characterized by a set of primitives and a placement rule (e.g., a tile floor ,bricks). stochastic textures : do not have easily identifiable primitives (e.g., granite, bark, sand). Many real-world textures have some mixture of these two (e.g.