ImageAlgo_opencv.h

#pragma once
#include <algorithm>

#include <opencv2/core.hpp>
#include <opencv2/highgui.hpp>
#include <opencv2/imgproc.hpp>

namespace imgalg {

using Point = cv::Point2i;
using ImgOrig = cv::Mat;
using ImgViewOrig = cv::Mat;
using Img = ImgOrig;
using Pixel = uint8_t;
using PixelOrig = uint8_t;
using PixelOut = cv::Vec3b;
using PixelT = uint8_t;
using Size = cv::Size;

class ImageAlgoBase {
public:
  static inline cv::Mat const &const_view(cv::Mat const &mat) { return mat; }
  static inline cv::Mat &view(cv::Mat &mat) { return mat; }
  static Size dimensions(cv::Mat const &mat) { return mat.size(); }
  static int num_channels(cv::Mat const& mat) { return mat.type() == CV_8UC3 ? 3 : 1; }
  static Img create_img(Size const &size) { return cv::Mat(size, CV_8UC3); }
  static Img scaled_down_gray(ImgViewOrig const &input_image, int const SF) {
	Img result;
    cv::resize(input_image, result, cv::Size(), 1. / SF, 1. / SF,
               cv::INTER_LINEAR_EXACT);
	cv::Mat gray(result.size(), CV_8UC1);
	cv::cvtColor(result, gray, cv::COLOR_BGR2GRAY);
	return gray;
  }
  template <typename P, typename V> 
  static P *row_begin(V &img, int const row) {
    return img.ptr<P>(row);
  }

  template <typename P, typename V>
  static P const *row_begin(V const &img, int const row) {
    return img.ptr<P>(row);
  }

  static void load_image(ImgOrig &orig, cv::String const &path) {
    orig = cv::imread(path, cv::IMREAD_UNCHANGED);
  }

  static bool save_image(ImgOrig const &img, cv::String const &path) {
    return cv::imwrite(path, img);
  }
};
} // namespace imgalg