fanfuhan OpenCV 教學094 ~ opencv-094-ORB之FAST特徵關鍵點檢測

資料來源: https://fanfuhan.github.io/

https://fanfuhan.github.io/2019/05/09/opencv-094/

GITHUB:https://github.com/jash-git/fanfuhan_ML_OpenCV

ORB-（定向快速且簡短的摘要）算法是基於FAST特徵檢測與BRIEF特徵描述子匹配實現，將BRIEF算法中的隨機方式獲取而值點對，ORB通過FAST方法，FAST方式查找特徵點方式假設灰度圖像預期點A周圍的預期存在連續大於或小於A的灰度值，選擇任意一個點P，假設尺寸為3，周圍16個表示表示。

C++

#include <opencv2/opencv.hpp>
#include <iostream>

using namespace cv;
using namespace std;

int main(int argc, char** argv) {
	Mat src = imread("D:/images/grad.png");
	auto orb_detector = ORB::create(1000);
	vector<KeyPoint> kpts;
	orb_detector->detect(src, kpts);
	Mat result = src.clone();
	drawKeypoints(src, kpts, result, Scalar::all(-1), DrawMatchesFlags::DEFAULT);
	imshow("ORB-detector", result);
	imwrite("D:/result.png", result);
	waitKey(0);
	return 0;
}

Python

"""
ORB之FAST特征关键点检测
"""

import cv2 as cv

src = cv.imread("images/test4.jpg")
cv.imshow("input", src)

orb = cv.ORB().create()
kps = orb.detect(src)
# opencv4 python版中好像没有 cv.drawKeypoints()
# result = cv.drawKeypoints(src, kps, None, (0, 255, 0), cv.DrawMatchesFlags_DEFAULT)
result = src.copy()
for marker in kps:
    result = cv.drawMarker(src, tuple(int(i) for i in marker.pt), color=(0, 255, 0))

cv.imshow("result", result)
cv.waitKey(0)
cv.destroyAllWindows()