Chapter 3: Image processing and computer vision Edge detection and image filtering by prof K H Wong Computer Science and engineering dept. CUHK khong@cse cuhk. edu. hk Tutorial for CMSC5711: Edge vo. 1a
Chapter 3: Image processing and computer vision Edge detection and image filtering by Prof. K.H. Wong, Computer Science and Engineering Dept. CUHK khwong@cse.cuhk.edu.hk Tutorial for CMSC5711 : Edge v0.1a 1
ear Introduction Edge detection by differentiation and threshold Convolution math tool Edge mask: edge detection by convolution(e.g Sobel) Image Filtering: smoothing, high pass etc Laplacian method 2nd order derivative method Laplacian of Gaussian: LOG smoothing and edge detection together Canny Edge Detection Most popular method Tutorial for CMSC5711: Edge vo. 1a
You will learn • Introduction: Edge detection by differentiation and threshold • Convolution math tool • Edge mask : edge detection by convolution (e.g. Sobel) • Image Filtering: smoothing, high pass etc. • Laplacian method : 2nd order derivative method. • Laplacian of Gaussian :LOG smoothing and edge detection together • Canny Edge Detection: Most popular method Tutorial for CMSC5711 : Edge v0.1a 2
opICS Edge detection First order derivative g(0 Second order derivative v2l a gray level image I has many sharp edges Tutorial for CMSC5711: Edge vo. 1a
Topics • Edge detection • First order derivative G(I) • Second order derivative 2 I A gray level image I has many sharp edges Tutorial for CMSC5711 : Edge v0.1a 3
What are edges and why we need them? Features have many applications: recognition tracking etc The most common are Point edges Shape intensity change positions Boundary edges Shape intensity changing lines Tutorial for CMSC5711: Edge vo. 1a
What are edges and why we need them? • Features have many applications: recognition, tracking etc. • The most common are • Point edges • Shape intensity change positions • Boundary edges • Shape intensity changing lines Tutorial for CMSC5711 : Edge v0.1a 4
Sobel demo D⊥addn33fns http://www.youtube.com/watch?v=z_a6e30a0xo Tutorial for CMSC5711: Edge vo. 1a 5
Sobel Demo • http://www.youtube.com/watch?v=z_a6e30aOXo Tutorial for CMSC5711 : Edge v0.1a 5