Lecture 3. Edge Detection, Texture Computer Vision Lecture 3. Edge Detection, Texture Oleh Tretiak © 2005
Lecture Outline Noise and Filtering, 8.1-8.2 Edge Detection 8.3, 8.3.1 Texture - what is it? Filter banks for texture detection 9.1 LaPlacian pyramid and texture analysis Oleh Tretiak © 2005
White Gaussian Noise Oleh Tretiak © 2005
Effect of Filters on Noise White noise convolved with Gaussian filter. r is a parameter proportional to the width of the filter. Noise standard deviation decreases with increasing r. r = 2, = 6.25 r = 4, = 3.7 r = 5, = 3.1 r = 3, = 4.65 Oleh Tretiak © 2005
Gaussian Edge Detection Step change of 10 with noise, = 25. Differentiation cannot detect the edges. Oleh Tretiak © 2005
Gaussian Edge Detection Step plus noise after Gaussian filter Laplacian filter applied to image on left Horizontal derivative applied to image on left Oleh Tretiak © 2005
Laplacian Edge Detection Oleh Tretiak © 2005
Gaussian Pyramid Oleh Tretiak © 2005
What is Texture? Oleh Tretiak © 2005
Natural Textures Oleh Tretiak © 2005
Texture Filters Oleh Tretiak © 2005
Application of Texture Filters Oleh Tretiak © 2005
Periodicity in Texture Oleh Tretiak © 2005
Periodicity? Oleh Tretiak © 2005
Gabor Filters Oleh Tretiak © 2005
Laplacian Pyramid Oleh Tretiak © 2005