Introduction to OpenCV

LNMIIT DIP Winter Workshop 2011. Manohar Kuse Introduction to OpenCV

Outline • What is OpenCV • Installing Ubuntu • Installing OpenCV • Coding with OpenCV • References for OpenCV LNMIIT DIP Winter Workshop 2011. Manohar Kuse

What is OpenCV • C++ Library for Image Processing and Computer Vision • Developed by Intel • Can take advantage of multiple processors • Developed for high performance • Support for Web-cam, Microsoft Connect and other specialized cameras LNMIIT DIP Winter Workshop 2011. Manohar Kuse

Linux Vs. Windows • Recommended : Install on Linux • NOT Recommended : OpenCV on Windows LNMIIT DIP Winter Workshop 2011. Manohar Kuse

Installing Linux http://www.ubuntu.com/download/ubuntu/windows-installer LNMIIT DIP Winter Workshop 2011. Manohar Kuse

OpenCV Installation • Open Synaptic Package Manager LNMIIT DIP Winter Workshop 2011. Manohar Kuse

OpenCV Installation • Set Proxy LNMIIT DIP Winter Workshop 2011. Manohar Kuse

OpenCV Installation • Search & Install “opencv-dev” LNMIIT DIP Winter Workshop 2011. Manohar Kuse

Sample Code • Header Files #include <stdlib.h> #include <stdio.h> #include <math.h> #include <cv.h> #include <highgui.h> Sample code and compilation instructions : Opencv kit for download on “lnmiitdip.wordpress.com” LNMIIT DIP Winter Workshop 2011. Manohar Kuse

Sample Code IplImage* img = 0;  Declaration of opencv-image char * fileName = “file.png”; img=cvLoadImage(fileName); Load image as a struct LNMIIT DIP Winter Workshop 2011. Manohar Kuse

IplImage • Height : img->height • Width : img->width • Channels : img->nChannels • (Number of channels) • Data : img->imageData • (Array of size W x H x nC LNMIIT DIP Winter Workshop 2011. Manohar Kuse

Sample Code • Iterate through the IplImage for(i=0;i<height;i++) { for(j=0;j<width;j++) { for(k=0;k<channels;k++) { data[i*step+j*channels+k]=255- data[i*step+j*channels+k]; } } } LNMIIT DIP Winter Workshop 2011. Manohar Kuse

Sample Code cvNamedWindow("mainWin“,CV_WINDOW_AUTOSIZE); Create a display window cvShowImage("mainWin", img );  Show Image cvWaitKey(0);  Give delay (Pause) LNMIIT DIP Winter Workshop 2011. Manohar Kuse

Links OpenCV Introduction: http://www.cs.iit.edu/~agam/cs512/lect-notes/opencv-intro/opencv-intro.html OpenCV E-Book: “Learning OpenCV” By Gary Bradski and Adrian Kaehler Official Site: http://opencv.willowgarage.com/wiki/ LNMIIT DIP Winter Workshop 2011. Manohar Kuse

Download • Download “OpenCV Kit” – lnmiitdip.wordpress.com • Contains • Instruction for compilation • Sample code • Video dataset LNMIIT DIP Winter Workshop 2011. Manohar Kuse

Thanks  LNMIIT DIP Winter Workshop 2011. Manohar Kuse

Introduction to OpenCV