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openFrameworks + ofxOpenCVでフィルタリング処理

openFrameworksのアドオンofxOvenCVを使ってカメラ画像にフィルタリングの画像処理を行うプログラムを作った.

フィルターは,左右矢印キーで変更できる. 以下,各フィルターについて解説.

1. オリジナル (original)

カメラ画像をそのまま表示. f:id:aa_debdeb:20160714102448p:plain

2. グレースケール (gray)

f:id:aa_debdeb:20160714102531p:plain

3. 二値化(binary)

-/+で閾値を変更可能 f:id:aa_debdeb:20160714102615p:plain

4. 輪郭を抽出 (contour)

二値化した画像から一定以上の大きさのブロックになっているところを抽出? まだ,よくわかってない. f:id:aa_debdeb:20160714102652p:plain

5. ぼかす (blur)

-/+でぼかしの強さを変更可能 f:id:aa_debdeb:20160714102727p:plain

6. コントラストを強める (contrast)

明るいところではわかりづらいが,暗いところでは,暗視カメラで見た時のような感じになる. f:id:aa_debdeb:20160714102801p:plain

7. エッジ検出 (canny)

キャニー法による. f:id:aa_debdeb:20160714102834p:plain

8. 色の反転 (invert)

f:id:aa_debdeb:20160714102940p:plain

9. 膨張 (dilate)

膨張・収縮・オープニング・クロージング 画像処理ソリューション f:id:aa_debdeb:20160714103048p:plain

10. 収縮 (erode)

f:id:aa_debdeb:20160714103144p:plain

11. 差分をとる (absDiff)

一フレーム前のカメラ画像との差分をとる. f:id:aa_debdeb:20160714103249p:plain

ソースは以下のような感じ.


#include "ofApp.h"

#define MAX_STATE 11

ofVideoGrabber videoGrabber;
ofxCvColorImage originalImage;
ofxCvGrayscaleImage grayImage;
ofxCvGrayscaleImage binaryImage;
ofxCvColorImage blurImage;
ofxCvGrayscaleImage contrastImage;
ofxCvGrayscaleImage cannyImage;
ofxCvColorImage invertImage;
ofxCvColorImage dilateImage;
ofxCvColorImage erodeImage;
ofxCvContourFinder contourFinder;
ofxCvGrayscaleImage absDiffImage;

int currentState = 0;
std::string stateNames[] = {"1. original", "2. gray", "3. binary", "4. contour", "5: blur",
                            "6: contrast", "7. canny", "8. invert", "9. dilate", "10. erode",
                            "11: absDiff"};
int binaryTheshold = 80;
int blurValue = 9;
ofxCvGrayscaleImage pGrayImage;

//--------------------------------------------------------------
void ofApp::setup(){
    ofBackground(200);
    videoGrabber.initGrabber(ofGetWidth(), ofGetHeight());
    originalImage.allocate(ofGetWidth(), ofGetHeight());
    grayImage.allocate(ofGetWidth(), ofGetHeight());
    binaryImage.allocate(ofGetWidth(), ofGetHeight());
    blurImage.allocate(ofGetWidth(), ofGetHeight());
    contrastImage.allocate(ofGetWidth(), ofGetHeight());
    cannyImage.allocate(ofGetWidth(), ofGetHeight());
    invertImage.allocate(ofGetWidth(), ofGetHeight());
    dilateImage.allocate(ofGetWidth(), ofGetHeight());
    erodeImage.allocate(ofGetWidth(), ofGetHeight());
    absDiffImage.allocate(ofGetWidth(), ofGetHeight());
    
    currentState = 0;
    pGrayImage.allocate(ofGetWidth(), ofGetHeight());
}

//--------------------------------------------------------------
void ofApp::update(){
    ofSetColor(255);
    videoGrabber.update();
    if(videoGrabber.isFrameNew()){
        originalImage.setFromPixels(videoGrabber.getPixels(), ofGetWidth(), ofGetHeight());
        grayImage = originalImage;
        // binary image
        binaryImage = originalImage;
        binaryImage.threshold(binaryTheshold);
        switch(currentState){
            case 3:
                ofSetColor(255, 0, 0);
                contourFinder.findContours(binaryImage, 20, 500, 100, true);
                break;
            case 4: // blur image
                blurImage = originalImage;
                blurImage.blur(blurValue);
                break;
            case 5: // contrast image
                contrastImage = originalImage;
                contrastImage.contrastStretch();
                break;
            case 6: // canny image
                cvCanny(grayImage.getCvImage(), cannyImage.getCvImage(), 60, 150);
                cannyImage.flagImageChanged();
                break;
            case 7: // invert image
                invertImage = originalImage;
                invertImage.invert();
                break;
            case 8: // dilate image
                dilateImage = originalImage;
                dilateImage.dilate();
                break;
            case 9: // erode image
                erodeImage = originalImage;
                erodeImage.erode();
                break;
            case 10:
                absDiffImage.absDiff(pGrayImage, grayImage);
                break;
        }
    }
    pGrayImage = grayImage;
}

//--------------------------------------------------------------
void ofApp::draw(){
    switch (currentState) {
        case 0:
            originalImage.draw(0, 0);
            break;
        case 1:
            grayImage.draw(0, 0);
            break;
        case 2:
            binaryImage.draw(0, 0);
            break;
        case 3:
            ofSetColor(30);
            ofRect(0, 0, ofGetWidth(), ofGetHeight());
            contourFinder.draw(0, 0);
            break;
        case 4:
            blurImage.draw(0, 0);
            break;
        case 5:
            contrastImage.draw(0, 0);
            break;
        case 6:
            cannyImage.draw(0, 0);
            break;
        case 7:
            invertImage.draw(0, 0);
            break;
        case 8:
            dilateImage.draw(0, 0);
            break;
        case 9:
            erodeImage.draw(0, 0);
            break;
        case 10:
            absDiffImage.draw(0, 0);
            break;
    }

    int previousState = currentState > 0 ? currentState - 1 : MAX_STATE - 1;
    int nextState = currentState < MAX_STATE - 1 ? currentState + 1 : 0;
    std::string navigator = stateNames[previousState] +
                                  " < " + stateNames[currentState] +
                                  " > " + stateNames[nextState];
    
    ofSetColor(128);
    ofDrawBitmapString(navigator, 50, 50);
    switch(currentState){
        case 2:
        case 3:
            ofDrawBitmapString("threshold(-/+): " + ofToString(binaryTheshold), 50, 70);
            break;
        case 4:
            ofDrawBitmapString("blur value(-/+): " + ofToString(blurValue), 50, 70);
            break;
    }

}

//--------------------------------------------------------------
void ofApp::keyPressed(int key){
    switch(key){
        case OF_KEY_LEFT:
            currentState = currentState > 0 ? currentState - 1 : MAX_STATE - 1;
            break;
        case OF_KEY_RIGHT:
            currentState = currentState < MAX_STATE - 1 ? currentState + 1 : 0;
            break;
        case '+':
            switch(currentState){
                case 2:
                case 3:
                    binaryTheshold = binaryTheshold < 255 ? binaryTheshold + 1 : 255;
                    break;
                case 4:
                    blurValue = blurValue < 99 ? blurValue + 2: 99;
                    break;
            }
            break;
        case '-':
            switch(currentState){
                case 2:
                case 3:
                    binaryTheshold = binaryTheshold > 0 ? binaryTheshold - 1 : 0;
                    break;
                case 4:
                    blurValue = blurValue > 1 ? blurValue - 2: 1;
            }
            break;
    }
}

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

}

//--------------------------------------------------------------
void ofApp::mouseMoved(int x, int y ){

}

//--------------------------------------------------------------
void ofApp::mouseDragged(int x, int y, int button){

}

//--------------------------------------------------------------
void ofApp::mousePressed(int x, int y, int button){

}

//--------------------------------------------------------------
void ofApp::mouseReleased(int x, int y, int button){

}

//--------------------------------------------------------------
void ofApp::windowResized(int w, int h){

}

//--------------------------------------------------------------
void ofApp::gotMessage(ofMessage msg){

}

//--------------------------------------------------------------
void ofApp::dragEvent(ofDragInfo dragInfo){ 

}

プロジェクトはgithubに. openFrameworks/openCVImageProcessing at master · aa-debdeb/openFrameworks

参考