一、簡介
1、OpenCV的特點
(1) 總體描述
- OpenCV是一個基於C/C++語言的開源圖像處理函數庫
- 其代碼都經過優化,可用於實時處理圖像
- 具有良好的可移植性
- 可以進行圖像/視頻載入、保存和採集的常規操作
- 具有低級和高級的應用程序接口(API)
- 提供了面向Intel IPP高效多媒體函數庫的接口,可針對你使用的Intel CPU優化代碼,提高程序性能(譯註:OpenCV 2.0版的代碼已顯着優化,無需IPP來提升性能,故2.0版不再提供IPP接口)
(2) 功能
- 圖像數據操作(內存分配與釋放,圖像複製、設定和轉換)
Image data manipulation (allocation, release, copying, setting, conversion). - 圖像/視頻的輸入輸出(支持文件或攝像頭的輸入,圖像/視頻文件的輸出)
Image and video I/O (file and camera based input, image/video file output). - 矩陣/向量數據操作及線性代數運算(矩陣乘積、矩陣方程求解、特徵值、奇異值分解)
Matrix and vector manipulation and linear algebra routines (products, solvers, eigenvalues, SVD). - 支持多種動態數據結構(鏈表、隊列、數據集、樹、圖)
Various dynamic data structures (lists, queues, sets, trees, graphs). - 基本圖像處理(去噪、邊緣檢測、角點檢測、採樣與插值、色彩變換、形態學處理、直方圖、圖像金字塔結構)
Basic image processing (filtering, edge detection, corner detection, sampling and interpolation, color conversion, morphological operations, histograms, image pyramids). - 結構分析(連通域/分支、輪廓處理、距離轉換、圖像矩、模板匹配、霍夫變換、多項式逼近、曲線擬合、橢圓擬合、狄勞尼三角化)
Structural analysis (connected components, contour processing, distance transform, various moments, template matching, Hough transform, polygonal approximation, line fitting, ellipse fitting, Delaunay triangulation). - 攝像頭定標(尋找和跟蹤定標模式、參數定標、基本矩陣估計、單應矩陣估計、立體視覺匹配)
Camera calibration (finding and tracking calibration patterns, calibration, fundamental matrix estimation, homography estimation, stereo correspondence). - 運動分析(光流、動作分割、目標跟蹤)
Motion analysis (optical flow, motion segmentation, tracking). ##目標識別(特徵方法、HMM模型)
Object recognition (eigen-methods, HMM). - 基本的GUI(顯示圖像/視頻、鍵盤/鼠標操作、滑動條)
Basic GUI (display image/video, keyboard and mouse handling, scroll-bars). ##圖像標註(直線、曲線、多邊形、文本標註)
Image labeling (line, conic, polygon, text drawing)
(3) OpenCV模塊
- cv – 核心函數庫
- cvaux – 輔助函數庫
- cxcore – 數據結構與線性代數庫
- highgui – GUI函數庫 graphical user interface
- ml – 機器學習函數庫 machine learing
2、有用的學習資源
(1) 參考手冊:
- < opencv-root >/docs/index.htm (譯註:在你的OpenCV安裝目錄< opencv-root >內)
(2) 網絡資源:
- 官方網站: http://www.intel.com/technology/computing/opencv/
- 軟件下載: http://sourceforge.net/projects/opencvlibrary/
(3) 書籍:
- Open Source Computer Vision Library
by Gary R. Bradski, Vadim Pisarevsky, and Jean-Yves Bouguet, Springer, 1st ed. (June, 2006). chenyusiyuan: 補充以下書籍 - Learning OpenCV - Computer Vision with the OpenCV Library
by Gary Bradski & Adrian Kaehler, O’Reilly Media, 1 st ed. (September, 2008). - OpenCV教程——基礎篇
作者:劉瑞禎 於仕琪,北京航空航天大學出版社,出版日期:200706
(4) 視頻處理例程(在 < opencv-root >/samples/c/):
- 顏色跟蹤: camshiftdemo
- 點跟蹤: lkdemo
- 動作分割: motempl
- 邊緣檢測: laplace
(5) 圖像處理例程 (在 < opencv-root>/samples/c/):
- 邊緣檢測: edge
- 圖像分割: pyramid_segmentation
- 形態學: morphology
- 直方圖: demhist
- 距離變換: distrans
- 橢圓擬合: fitellipse
3、C++例程
////////////////////////////////////////////////////////////////////////
//
// hello-world.cpp
//
// 該程序從文件中讀入一幅圖像,將之反色,然後顯示出來.
//////////////////////////////////////////////////////////////////////////
include <stdlib.h>
include <stdio.h>
include <math.h>
include <cv.h>
include <highgui.h>
int main(int argc, char *argv[])
{
IplImage* img = 0;
int height,width,step,channels;
uchar *data;
int i,j,k;
if(argc<2){
printf("Usage: main <image-file-name>\n\7");
exit(0);
}
// load an image
img=cvLoadImage(argv[1]);
if(!img){
printf("Could not load image file: %s\n",argv[1]);
exit(0);
}
// get the image data
height = img->height;
width = img->width;
step = img->widthStep;
channels = img->nChannels;
data = (uchar *)img->imageData;
printf("Processing a %dx%d image with %d channels\n",height,width,channels);
// create a window
cvNamedWindow("mainWin", CV_WINDOW_AUTOSIZE);
cvMoveWindow("mainWin", 100, 100);
// invert the image
// 相當於 cvNot(img);
// IplImage *pDstImg = cvCreateImage(cvGetSize(img),img->depth,img->nChannels);
// cvNot(img, pDstImg);
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];
// show the image
cvShowImage("mainWin", img );
// wait for a key
cvWaitKey(0);
// release the image
cvReleaseImage(&img );
return 0;
}
二、GUI 指令
1、窗口管理
(1) 創建和定位一個新窗口:
cvNamedWindow("win1", CV_WINDOW_AUTOSIZE);
cvMoveWindow("win1", 100, 100); // offset from the UL corner of the screen
(2) 載入圖像:
IplImage* img=0;
img=cvLoadImage(fileName, CV_LOAD_IMAGE_COLOR);
if(!img) printf("Could not load image file: %s\n",fileName);
(3) 顯示圖像:
cvShowImage("win1",img);
(4) 關閉窗口:
cvDestroyWindow("win1");
(5) 改變窗口大小:
cvResizeWindow("win1",100,100); // new width/heigh in pixels
2、輸入處理
(1) 處理鼠標事件:
定義一個鼠標處理程序:
void mouseHandler(int event, int x, int y, int flags, void* param) { switch(event){ case CV_EVENT_LBUTTONDOWN: if(flags & CV_EVENT_FLAG_CTRLKEY) printf("Left button down with CTRL pressed\n"); break; case CV_EVENT_LBUTTONUP: printf("Left button up\n"); break; } }
x,y: 相對於左上角的像素座標
event: CV_EVENT_LBUTTONDOWN, CV_EVENT_RBUTTONDOWN, CV_EVENT_MBUTTONDOWN,
CV_EVENT_LBUTTONUP, CV_EVENT_RBUTTONUP, CV_EVENT_MBUTTONUP,
CV_EVENT_LBUTTONDBLCLK, CV_EVENT_RBUTTONDBLCLK, CV_EVENT_MBUTTONDBLCLK,
CV_EVENT_MOUSEMOVE:flags: CV_EVENT_FLAG_CTRLKEY, CV_EVENT_FLAG_SHIFTKEY, CV_EVENT_FLAG_ALTKEY,
CV_EVENT_FLAG_LBUTTON, CV_EVENT_FLAG_RBUTTON, CV_EVENT_FLAG_MBUTTON
註冊該事件處理程序:
mouseParam=5;
cvSetMouseCallback(“win1”,mouseHandler,&mouseParam); //第三個參數可以設置爲NULL
(未完待續)