python image feature detection algorithm (1): Python implementation sift and Harris
In this paper, we will introduce two local descriptor algorithms for image matching. sift[paper Links] and Harris, they are in many applications have a relatively important role, such as target matching, target tracking, creating panorama, augmented reality technology and the calculation of the three-dimensional image recon
Corner PointFeature detection and matching is an important part of the computer Vision application, which needs to find the characteristics of the image to establish the corresponding relationship. Point, which is the special position in the image, is a very common feature, the local feature of the point can also be called "key feature Point" (KeyPoint feature), or "point of interest" (interestpoint), or "Corner" ( Conrner).There are several specific descriptions of corner points:
The
Pure reading, please visit OPENCV using the Harris Algorithm for corner detectionSourceKqwopencvfeaturesdemoA corner point is an intersection of two edges or a point that has several significant edge orientations in a local neighborhood. Harris Corner Point Detection is one of the most common techniques in corner detection.The Harris corner detector uses a slidin
Harris Corner Point algorithm
Feature point detection is widely used in target matching, target tracking, three-dimensional reconstruction and other applications, in the target modeling will be the image of the target feature extraction, commonly used color, corner point, feature points, contour, texture and other characteristics. Now we begin to explain the common feature point detection, in which Harris
Computer Vision Discussion Group 162501053 reprinted Please note: http://blog.csdn.net/abcd1992719g/article/details/26824529Income in the bag
Use OpenCV connerHarris for Corner Detection
Implement the Harris algorithm by yourself
Below is a self-implemented
Because the threshold value is relatively high, it is not found around the house
Before that, we talked about edge detection. The basic principle of edge detection is that the gradient in the
the squared difference between two patches, and the smaller the SSD value, the higher the similarity.If the pixels are in a smooth image area, the patches around are very similar. If the pixels are on the edge, the surrounding patches are very different in the direction orthogonal to the edges, and are more similar in the direction parallel to the edges. If the pixel is a feature point that changes in all directions, all patches around it will not be very similar.The Moravec calculates the SSD
1. Significance of Feature point extraction
2. Corner Point
3. The fundamentals of Harris Corner Point detection
steps for 4.Harris corner detection algorithm
design of 5.Harris corner point extraction algorithm
6. Experimental results show
7. Supplementary reading materials
IntroductionThis paper is mainly to deduce the mathematical formula of Harris Corner detection, and to understand the theoretical knowledge more deeply.Pre-Knowledgerepresentation of the matrix equation of an ellipseIn high school textbooks, we learned about standard ellipses and their equations (as shown):In fact, the matrix in the operation of a very broad, now the above standard equation is written in matrix form (convenient next processing):the re
A corner is a point that changes in multiple directions at the same time. It is more unique than an edge. Corner detection is widely used in many scenarios, such as fingerprint feature extraction in fingerprint detection and sparse optical flow computing.
The basic idea of Harris corner's corner points is to observe through a small window, so it is easy to identify the corner points. In these directions, the brightness distribution of the window var
2012-07-31 13:25
Corner Point
Feature detection and matching is an important part of the computer Vision application, which needs to find the characteristics of the image to establish the corresponding relationship. Point, which is the special position in the image, is a very common feature, the local feature of the point can also be called "key feature Point" (KeyPoint feature), or "point of interest" (interestpoint), or "Corner" ( Conrner).
The specific description of the corner point can b
Image detection is the basis of image segmentation and image recognition, and is also an indispensable key. In the framework of visual computing theory, extracting the basic features of two-dimensional image, such as edge, corner and texture, is the first step of the whole frame. This article has made a detailed theory introduction and related realization to the Harris Corner point algorithm.
Part One : Corner type Introduction
In the real world, cor
Harris is most commonly used as a feature detection algorithm.First file harris.pyA second file test algorithmFrom PIL import imagefrom numpy import *import harrisfrom pylab import *from scipy.ndimage import Filtersim=array (image.op En (' 33.jpg '). Convert (' L ')) Harrisim=harris.compute_harris_response (IM) filtered_coords=harris.get_harris_points ( Harrisim) harris.plot_harris_points (im,filtered_coords) Copyright notice: This article blog origin
Python implementation of the harris algorithm, harrispython
Harris is the most common feature detection algorithm.
First file harris. py
Algorithm for testing the second file
from PIL import Imagefrom numpy import *import harrisfrom pylab import *from scipy.ndimage import filtersim=array(Image.open('33.jpg').convert('L'))harrisim=harris.compute_harris_respo
Because the current plan is familiar with the language and library, and the image feature extraction theory is very boring, and it is likely to be inefficient, so the computer Vision feature extraction This Part skipped, direct start and deep learning with a closer target detection recognition part.This section describes the functions that extract the corner features of an image in OpenCV3:1# coding=utf-82 Import Cv23Import NumPy asNP4 5 6 " "Corner feature extraction of
1. First of all, we can't help but ask what is Harris corner point.
For corner points, there is no clear mathematical definition so far. But you can think of a corner point as the extreme point, that is, the point where the attribute is particularly prominent. General corner Detection is a specific definition, or can be specific detection of points of interest detection. This means that the point of interest can be a corner point, an isolated point wi
detect corner points, such methods are more representative of: Moravec,forstner,harris,susan.
Harris Corner Point detection:
The following figure illustrates the principle of Harris Corner point detection:A simple introduction is to set a small window with a fixed size and move the window. Statistic the change of pixels in the window before and after moving to
For the implementation routine of this article, see the English tutorial feature2d module.2d features framework-> Harris corner detector
The specific algorithm uses the Taylor expansion to obtain the maximum change point of the pixel value in the window, that is, the corner point position.
/** * @function cornerHarris_Demo.cpp * @brief Demo code for detecting corners using Harris-Stephens method * @author
Harris is the most common feature point detection algorithm.First file harris.pyThe second Test algorithm for a fileFrom PIL import imagefrom numpy import *import harrisfrom pylab import *from scipy.ndimage import Filtersim=array (image.op En (' 33.jpg '). Convert (' L ')) Harrisim=harris.compute_harris_response (IM) filtered_coords=harris.get_harris_points ( Harrisim) harris.plot_harris_points (im,filtered_coords)Python implementation of
solution will not be guaranteed.
Solution 2: wired
The cable solution can only deploy single-mode optical fiber cables at a distance of 12 kilometers, which is more time-consuming and costly. You can say you don't have to think about it.
Solution 3: Internet + VPN
The Internet can be said to be a public wide area network, and many telecom operators have established a four-way and eight-way long-distance network, which makes it possible for our compan
The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion;
products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the
content of the page makes you feel confusing, please write us an email, we will handle the problem
within 5 days after receiving your email.
If you find any instances of plagiarism from the community, please send an email to:
info-contact@alibabacloud.com
and provide relevant evidence. A staff member will contact you within 5 working days.