S. Mandayam/ DIP/ECE Dept./Rowan University Digital Image Processing ECE /ECE Fall 2007 Shreekanth Mandayam ECE Department Rowan University Lecture 2 September 17, 2007

S. Mandayam/ DIP/ECE Dept./Rowan UniversityPlan Sampling & Quantization Pixel Operations Point processing Histogram equalization Connectivity Lab Project 1 individual pixels all pixels neighboring pixels

S. Mandayam/ DIP/ECE Dept./Rowan University DIP: Details

S. Mandayam/ DIP/ECE Dept./Rowan University Sampling & Quantization Sampling demos/demo1sampling_and_quantization/demo_sampling.m Quantization demos/demo1sampling_and_quantization/demo_quant.m

S. Mandayam/ DIP/ECE Dept./Rowan University Image Preprocessing Enhancement Restoration Spatial Domain Spectral Domain Point Processing >>imadjust >>histeq Spatial filtering >>filter2 Filtering >>fft2/ifft2 >>fftshift Inverse filtering Wiener filtering

S. Mandayam/ DIP/ECE Dept./Rowan University Point Processing (Intensity Transformation) s(x,y) = T{ r(x,y)} Transformed Gray Level Original Gray Level Transformation Function >>imadjdemo >>imadjust

S. Mandayam/ DIP/ECE Dept./Rowan University Point Processing 0 L r s r s r1r1 r2r2 s1s1 s2s2  >>imadjdemo >>imadjust

S. Mandayam/ DIP/ECE Dept./Rowan University Image Histogram >>imadjdemo >>imhist

S. Mandayam/ DIP/ECE Dept./Rowan University Histogram Equalization (Balancing) >>imadjdemo >>histeq

S. Mandayam/ DIP/ECE Dept./Rowan University Pixel Connectivity (x+1,y-1) (x,y) (x+1,y) (x+1,y+1) (x,y+1) (x-1,y+1) (x-1,y-1) (x,y-1) (x-1,y) x y

S. Mandayam/ DIP/ECE Dept./Rowan University Labeling of Connected Components Begin scan Position: (x,y) p(x,y) = 1? p(x-1,y) = 1? p(x,y-1) = 1? p(x-1,y) AND p(x,y-1) = 1 class(x,y) = new class Update position (x,y) class(x,y) = class(x-1,y) class(x,y) = class(x,y-1) class(x-1,y) = class(x,y-1) All positions scanned? End scan y y y y y p(x-1,y) AND p(x,y-1) = 0 y

S. Mandayam/ DIP/ECE Dept./Rowan University Image Preprocessing Enhancement Restoration Spatial Domain Spectral Domain Point Processing >>imadjust >>histeq Spatial filtering >>filter2 Filtering >>fft2/ifft2 >>fftshift Inverse filtering Wiener filtering

S. Mandayam/ DIP/ECE Dept./Rowan University Lab 1: Pixel Operations

S. Mandayam/ DIP/ECE Dept./Rowan UniversitySummary