2017-05-04 2021-08-16
Camera, ComputerVision, Opencv, Python, Sensor

openFrameworks opencv webcam crop

openFrameworksでwebcamの画像をcropする with opencv

codes


x
#include "ofMain.h"
#include "ofApp.h"

//========================================================================
int main( ){

  ofSetupOpenGL(512,512, OF_WINDOW);      // <-------- setup the GL context

  // this kicks off the running of my app
  // can be OF_WINDOW or OF_FULLSCREEN
  // pass in width and height too:
  ofRunApp( new ofApp());

}


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#include "ofApp.h"

int cam_w;
int cam_h;
int target_w;
int target_h;

//--------------------------------------------------------------
void ofApp::setup(){
    cam_w = 320;
    cam_h = 240;
    target_w = 200;
    target_h = 200;

    vidGrabber.setVerbose(true);
    vidGrabber.initGrabber(cam_w,cam_h);
    vidGrabber.setup(cam_w,cam_h);

    colorImg_cam.allocate(cam_w,cam_h);
    colorImg.allocate(target_w,target_h);
  grayImage.allocate(target_w,target_h);
  grayBg.allocate(target_w,target_h);
  grayDiff.allocate(target_w,target_h);

  bLearnBakground = true;
  threshold = 80;
    ofGetWidth();
}

//--------------------------------------------------------------
void ofApp::update(){
  ofBackground(100,100,100);

    bool bNewFrame = false;

    vidGrabber.update();
    bNewFrame = vidGrabber.isFrameNew();

  if (bNewFrame){
        img.setFromPixels(vidGrabber.getPixels());
        colorImg_cam.setFromPixels(img.getPixels());
        img.crop((cam_w-target_w)/2, (cam_h-target_h)/2, target_w, target_h);
        colorImg.setFromPixels(img.getPixels());
        grayImage = colorImg;

    if (bLearnBakground == true){
      grayBg = grayImage;
      bLearnBakground = false;
    }

    grayDiff.absDiff(grayBg, grayImage);
    grayDiff.threshold(threshold);

    contourFinder.findContours(grayDiff, 20, target_w*target_h/2, 100, true);
        printf("value %d \n", contourFinder.nBlobs);
        
  }

}

//--------------------------------------------------------------
void ofApp::draw(){
    int ini_w = 50;
    int ini_h = 50;

  ofSetHexColor(0xffffff);
  colorImg_cam.draw(ini_w, ini_h);
  grayImage.draw(ini_w+(cam_w-target_w)/2, ini_h+(cam_h-target_h)/2);

    for (int i = 0; i < contourFinder.nBlobs; i++){
        contourFinder.blobs[i].draw(ini_w+(cam_w-target_w)/2, ini_h+(cam_h-target_h)/2);
    }
    
    ofSetHexColor(0xffffff);
    stringstream reportStr;
    reportStr << "bg subtraction and blob detection" << endl
              << "press ' ' to capture bg" << endl
          << "threshold " << threshold << " (press: +/-)" << endl
              << "num blobs found " << contourFinder.nBlobs << ", fps: " << ofGetFrameRate();
    ofDrawBitmapString(reportStr.str(), ini_w, ini_h+cam_h+50);

}

//--------------------------------------------------------------
void ofApp::keyPressed(int key){

  switch (key){
    case ' ':
      bLearnBakground = true;
      break;
    case '+':
      threshold ++;
      if (threshold > 255) threshold = 255;
      break;
    case '-':
      threshold --;
      if (threshold < 0) threshold = 0;
      break;
  }
}


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#pragma once

#include "ofMain.h"

#include "ofxOpenCv.h"

class ofApp : public ofBaseApp{

  public:
    void setup();
    void update();
    void draw();
    
    void keyPressed(int key);
    void keyReleased(int key);
    void mouseMoved(int x, int y );
    void mouseDragged(int x, int y, int button);
    void mousePressed(int x, int y, int button);
    void mouseReleased(int x, int y, int button);
    void mouseEntered(int x, int y);
    void mouseExited(int x, int y);
    void windowResized(int w, int h);
    void dragEvent(ofDragInfo dragInfo);
    void gotMessage(ofMessage msg);   

        ofVideoGrabber    vidGrabber;

        ofxCvColorImage     colorImg_cam;
        ofxCvColorImage     colorImg;

        ofxCvGrayscaleImage   grayImage;
    ofxCvGrayscaleImage   grayBg;
    ofxCvGrayscaleImage   grayDiff;

        ofxCvContourFinder  contourFinder;

    int         threshold;
    bool        bLearnBakground;

        ofImage img;

};