[OpenCV] Install openCV in Qt Creator
Learn openCV.pdf
qmake: link with opencv (Key Point)
QT += core gui
greaterThan(QT_MAJOR_VERSION, 4): QT += widgets
TARGET = displayimage
TEMPLATE = app
INCLUDEPATH += /usr/local/include/opencv
LIBS += -L/usr/local/lib -lopencv_core -lopencv_imgproc -lopencv_highgui
SOURCES += main.cpp\
mainwindow.cpp
HEADERS += mainwindow.h
FORMS += mainwindow.ui
main.cpp
#include "mainwindow.h" #include <QApplication> int main(int argc, char *argv[]) { QApplication a(argc, argv); MainWindow w; w.show(); return a.exec(); }
mainwindow.cpp
#include "mainwindow.h" #include "ui_mainwindow.h" #include <opencv2/opencv.hpp> //add MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent), ui(new Ui::MainWindow) { ui->setupUi(this); cv::Mat inputImage = cv::imread("/home/unsw/Pictures/me/lolo.JPG"); //add cv::imshow("Display Image", inputImage); //add } MainWindow::~MainWindow() { delete ui; }
ch2_ex2_1: 打开并显示图片
#include "highgui.h" int main( int argc, char** argv ) { // IplImage* img = cvLoadImage( argv[1] ); IplImage* img = cvLoadImage( "/home/unsw/Pictures/me/lolo.JPG", CV_WINDOW_AUTOSIZE); cvNamedWindow("lolo", CV_WINDOW_FREERATIO); cvShowImage("lolo", img ); cvWaitKey(0); cvReleaseImage( &img ); cvDestroyWindow("lolo"); }
ch2_ex2_2: 打开并显示视频
int main( int argc, char** argv ) { cvNamedWindow( "Example2", CV_WINDOW_AUTOSIZE ); //CvCapture* capture = cvCaptureFromAVI( argv[1] ); // either one will work CvCapture* capture = cvCreateFileCapture( "/home/unsw/test.avi" ); // 放每一帧的buf IplImage* frame; while(1) { frame = cvQueryFrame( capture ); if( !frame ) break; cvShowImage( "Example2", frame ); //不需要手动释放，capture的释放即顺便将其释放 char c = cvWaitKey(33); //33ms, 30frames per second. if( c == 27 ) break; } cvReleaseCapture( &capture ); cvDestroyWindow( "Example2" ); }
ch2_ex2_3: 打开并显示视频 + Control Bar
可以使用QT的图形界面控制，非重点here。
ch2_ex2_4: 平滑处理图片
#include "cv.h" #include "highgui.h" void example2_4( IplImage* image ) { // Create some windows to show the input // and output images in. // cvNamedWindow( "Example2_4-in", CV_WINDOW_AUTOSIZE ); cvNamedWindow( "Example2_4-out", CV_WINDOW_AUTOSIZE ); // Create a window to show our input image // cvShowImage( "Example2_4-in", image ); // Create an image to hold the smoothed output // IplImage* out = cvCreateImage( cvGetSize(image), IPL_DEPTH_8U, 3 ); // Do the smoothing // cvSmooth( image, out, CV_GAUSSIAN, 5,5,0,0 ); cvSmooth( out, out, CV_GAUSSIAN, 5,5,0,0); // Show the smoothed image in the output window // cvShowImage( "Example2_4-out", out ); // Be tidy // cvReleaseImage( &out ); // Wait for the user to hit a key, then clean up the windows // cvWaitKey( 0 ); cvDestroyWindow("Example2_4-in" ); cvDestroyWindow("Example2_4-out" ); } int main( int argc, char** argv ) { IplImage* img = cvLoadImage( argv[1] ); cvNamedWindow("Example1", CV_WINDOW_AUTOSIZE ); cvShowImage("Example1", img ); example2_4( img ); // cvWaitKey(0); cvReleaseImage( &img ); cvDestroyWindow("Example1"); }
ch2_ex2_8: 灰度化(Gray) --> 缩小图片(Pyr) --> 线条化(Canny)
#include "cv.h" #include "highgui.h" IplImage* doCanny( IplImage* in, double lowThresh, double highThresh, double aperture) { IplImage* out = cvCreateImage( cvGetSize( in ), in->depth, //IPL_DEPTH_8U, 1); cvCanny( in, out, lowThresh, highThresh, aperture ); return( out ); }; IplImage* doPyrDown( IplImage* in, int filter = IPL_GAUSSIAN_5x5) { // Best to make sure input image is divisible by two. // assert( in->width%2 == 0 && in->height%2 == 0 ); IplImage* out = cvCreateImage( cvSize( in->width/2, in->height/2 ), in->depth, in->nChannels ); cvPyrDown( in, out ); return( out ); }; int main( int argc, char** argv ) { cvNamedWindow("Example Gray", CV_WINDOW_AUTOSIZE ); cvNamedWindow("Example Pyr", CV_WINDOW_AUTOSIZE ); cvNamedWindow("Example Canny", CV_WINDOW_AUTOSIZE ); IplImage* img_rgb = cvLoadImage( "/home/unsw/lolo.jpg" ); IplImage* out; out = cvCreateImage( cvSize( img_rgb->width,img_rgb->height ), img_rgb->depth, 1); cvCvtColor(img_rgb, out ,CV_BGR2GRAY); cvShowImage("Example Gray", out );
out = doPyrDown( out ); out = doPyrDown( out ); cvShowImage("Example Pyr", out );
out = doCanny( out, 10, 100, 3 ); cvShowImage("Example Canny", out ); cvWaitKey(0); cvReleaseImage( &out); cvDestroyWindow("Example Gray"); cvDestroyWindow("Example Pyr"); cvDestroyWindow("Example Canny"); }
ch2_ex2_9: Camera: Preview & Capture
#include "cv.h" #include "highgui.h" int main( int argc, char** argv ) { cvNamedWindow( "Example2_9", CV_WINDOW_AUTOSIZE ); CvCapture* capture;
if (argc==1) { capture = cvCreateCameraCapture( 0 ); } else { capture = cvCreateFileCapture( argv[1] ); } assert( capture != NULL ); IplImage* frame; while(1) { frame = cvQueryFrame( capture ); if( !frame ) break; cvShowImage( "Example2_9", frame ); char c = cvWaitKey(40); if( c == 27 ) break; } cvReleaseCapture( &capture ); cvDestroyWindow( "Example2_9" ); }
ch2_ex2_10: 写入视频文件
#include "cv.h" #include "highgui.h" #include <stdio.h> #include <iostream> using namespace std; // Convert a video to grayscale // argv[1]: input video file // argv[2]: name of new output file // //#define NOWRITE 1; //Turn this on (removed the first comment out "//" if you can't write on linux main( int argc, char* argv[] ) {
cvNamedWindow( "Example2_10", CV_WINDOW_AUTOSIZE ); cvNamedWindow( "Log_Polar", CV_WINDOW_AUTOSIZE ); CvCapture* capture = cvCreateFileCapture( "/home/unsw/test.avi" ); if (!capture){ return -1; } IplImage* bgr_frame; double fps = cvGetCaptureProperty ( capture, CV_CAP_PROP_FPS ); printf("fps=%d\n",(int)fps); CvSize size = cvSize( (int)cvGetCaptureProperty( capture, CV_CAP_PROP_FRAME_WIDTH), (int)cvGetCaptureProperty( capture, CV_CAP_PROP_FRAME_HEIGHT) ); printf("frame (w, h) = (%d, %d)\n",size.width,size.height); #ifndef NOWRITE CvVideoWriter* writer = cvCreateVideoWriter( // On linux Will only work if you've installed ffmpeg development files correctly, "/home/unsw/test_out.avi", // otherwise segmentation fault. Windows probably better. CV_FOURCC('D','X','5','0'), fps, size ); #endif IplImage* logpolar_frame = cvCreateImage( size, IPL_DEPTH_8U, 3 ); IplImage* gray_frame = cvCreateImage( size, IPL_DEPTH_8U, 1 ); while( (bgr_frame=cvQueryFrame(capture)) != NULL ) { cvShowImage( "Example2_10", bgr_frame ); cvConvertImage( //We never make use of this gray image bgr_frame, gray_frame, CV_RGB2GRAY ); cvLogPolar( bgr_frame, logpolar_frame, //This is just a fun conversion the mimic's the human visual system cvPoint2D32f(bgr_frame->width/2, bgr_frame->height/2), 40, CV_INTER_LINEAR+CV_WARP_FILL_OUTLIERS ); cvShowImage( "Log_Polar", logpolar_frame ); //Sigh, on linux, depending on your ffmpeg, this often won't work ... #ifndef NOWRITE cvWriteToAVI( writer, logpolar_frame ); #endif char c = cvWaitKey(10); if( c == 27 ) break; } #ifndef NOWRITE cvReleaseVideoWriter( &writer ); #endif cvReleaseImage( &gray_frame ); cvReleaseImage( &logpolar_frame ); cvReleaseCapture( &capture ); }
