crop_image_openCvCXX/cropper.h

//
//  cropper.h
//  SlamView
//
//  Created by Mosong Cheng on 4/30/14.
//  Copyright (c) 2014 Mosong Cheng. All rights reserved.
//

#pragma once

#include <iostream>
#include "opencv2/highgui/highgui.hpp"
#include "opencv2/imgproc/imgproc.hpp"
#include "opencv2/imgcodecs.hpp"
using namespace std;
using namespace cv;

/** Usage: suppose you want to crop an image img, which is
 *  CV8UC3 mat, BGR color format. Call this class:
 *
 *      Cropper cropper;
 *      Mat cropped_image = cropper.crop(img);
 *
 * Or like this:
 *      Cropper cropper;
 *      Mat cropped_image;
 *      cv::Rect bound;
 *      cropper.crop(img, cropped_image, bound);
 *
 * Now #bound stores the bounding rectangle of the #cropped_image
 * inside the original #img.
 * **********************************************************/

class Cropper{
    public:
    int kstep = 10;

    public:
        /** cropping the image to rid the blank part **/
        Mat crop(const Mat& img);

        void crop(const Mat& src, Mat& dst, cv::Rect& dstBound);


        inline void setStep(int kp){
            kstep = kp;
        }

        void setROI(const cv::Rect& roi){
            finalROI = roi;
            // roi = [4165 x 2207 from (465, 253)]
        }

        ~Cropper(){
            mask.release();
        }

    private:
        Mat mask;
        cv::Rect rect;

        cv::Rect finalROI; // the final cropping from image

    private:
        void getMask(const Mat& img);
        void expandROI(cv::Rect& r);
        void framing();

        bool lineHasBlankPixels(const Point2i& st, const Point2i& ed);

        bool rectHasBlankPixels(const cv::Rect& roi);

        bool lineHasContent(const Point2i& st, const Point2i& ed);

        void searchContentLine(Point2i& p1, Point2i& p2, Point2i& delta);

};