util.cpp

#include "stdafx.h"
#include "util.h"
#include "common.h"

namespace fs = std::filesystem;

using namespace cv;

/* Histogram display function - display a histogram using bars (simlilar to L3 / PI)
Input:
name - destination (output) window name
hist - pointer to the vector containing the histogram values
hist_cols - no. of bins (elements) in the histogram = histogram image width
hist_height - height of the histogram image
Call example:
showHistogram ("MyHist", hist_dir, 255, 200);
*/
void showHistogram(const std::string& name, const int* hist, const int  hist_cols, const int hist_height)
{
	Mat imgHist(hist_height, hist_cols, CV_8UC3, CV_RGB(255, 255, 255)); // constructs a white image

	//computes histogram maximum
	int max_hist = 0;
	for (int i = 0; i < hist_cols; i++)
		if (hist[i] > max_hist)
			max_hist = hist[i];
	double scale = 1.0;
	scale = (double)hist_height / max_hist;
	int baseline = hist_height - 1;

	for (int x = 0; x < hist_cols; x++) {
		Point p1 = Point(x, baseline);
		Point p2 = Point(x, baseline - cvRound(hist[x] * scale));
		line(imgHist, p1, p2, CV_RGB(255, 0, 255)); // histogram bins colored in magenta
	}

	imshow(name, imgHist);
}

std::vector<std::string> getFilesInDir(const std::string& dirName)
{
	std::vector<std::string> files;

	for (const auto& entry : fs::directory_iterator(dirName)) {
		files.push_back(entry.path().string());
	}

	return files;
}

double degToRad(double degree)
{
	return (degree * (PI / 180.0));
}

double radToDeg(double radian)
{
	return (radian / (PI / 180.0));
}