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Image Processing

Negative Film

An implementation of digital image processing to change RGB image or colormap to negative-film image.

Requirements

  • OpenCV 
    # apt-get install libopencv-dev
# apt-get install cmake

Programming

  • create file Negative.cpp 
#include <cv.h>
#include <highgui.h>
#include <opencv2/imgproc/imgproc.hpp>
#include <stdio.h>

using namespace cv;
using namespace std;
// start of pixel navigation

Mat navigate(Mat img) {

    if(img.channels()==1){
        Mat_<uchar>::iterator it = img.begin<uchar>();
        Mat_<uchar>::iterator itend = img.end<uchar>();
        for(;it!=itend;it++){
            (*it) = 255 - (*it);
        }
    }
    if(img.channels()==3){
        Mat_<Vec3b>::iterator it = img.begin<Vec3b>();
        Mat_<Vec3b>::iterator itend = img.end<Vec3b>();
        for(;it!=itend;it++){
            (*it)[0] = 255 - (*it)[0];
            (*it)[1] = 255 - (*it)[1];
            (*it)[2] = 255 - (*it)[2];
        }
    }
    return img;
}

// end of pixel navigation

int main( int argc, char** argv )
{
    Mat src = cv::imread("../../lena.png", CV_LOAD_IMAGE_COLOR);

    if(! src.data){
        cout << "could not open or find the image" << endl;
        return -1;
    }
    Mat dst = navigate(src.clone());    
    imwrite("lena_negative.png", dst);

    return 0;

}

CMakeLists

  • Create CMakeLists.txt 
cmake_minimum_required(VERSION 2.8)
project( Negative )
find_package( OpenCV REQUIRED )
add_executable( Negative Negative.cpp )
target_link_libraries( Negative ${OpenCV_LIBS} )

Running

Original Negative Film
r r
  • The canvas tag is not supported in Internet Explorer 8 and earlier versions.
  • Try to Refresh this Page (e.q. Pressing F5) if you cannot see the result.

Reference