opencv printing weird black images

opencv imwrite is printing weird black(ish) images in my C++ code. An example code to read an image and then print it out is following:

#include "iostream"
#include "opencv2/core/core.hpp"
#include "opencv2/highgui/highgui.hpp"
using namespace std;

int main()
{
    cv::Mat input_image = cv::imread("input_image.tiff",0);
    cv::imwrite("output_image.tiff",input_image);

    return 0;
}

I compile it as g++ -std=c++11 main.cc -o bin `pkg-config --cflags --libs opencv`

The input image and output image are as follows (should be the same):

Input Image Output Image

The image is being read correctly as I have checked it by accessing different pixel values.Therefore the problem is in imwrite.

Extra Info: The code was working fine in the beginning but suddenly changed its behavior, reinstalling opencv and its libraries doesn't help.

Can someone please tell what is wrong here,

Thanks