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template matching Template matching is often used in image processing. This algorithm is mainly used to find the same area in the image as the template image. In addition, it is also used for image positioning. The specified position is found through template matching, and then subsequent processing is carried out. The principle of templa ...

Personal data, for learning purposes only Modification time - 21:11:31, February 19, 2022 Course of study: OpenCV4 image processing and video analysis practical tutorial Lecturer: Jia Zhigang 13 custom filtering opencv knowledge points: Convolute image with kernel - filter2DScaling takes absolute value and converts it to 8 bits - convertSc ...

preface In computer vision tasks, such as image classification, image data set is essential. The pictures collected by yourself often have a lot of noise or useless information, which will affect the model training. Therefore, the image needs to be cropped to prevent the useless information at the edge of the image from affecting the mod ...

Download content opencv3.2. Download address: https://opencv.org/opencv-3-2/ Contrib download address: https://github.com/opencv/opencv_contrib/releases?after=3.3.1 cmake download. Note that versions 3.6.1, 3.9 and 3.12 are available, but higher versions such as 3.20 cannot be used. You can download it from the official website https://cmake.o ...

Record the code. Standard Hough transform HoughLines() HoughLines(midImage, lines, 1, CV_PI/180, 150, 0, 0 ); The function input image is 8-bit single channel binary After calling HoughLines function, the output vector of the line detected by Hough line transformation is stored. Each line consists of a vector with two elements( ρ，θ ...

In slam, optical flow tracking judges the dynamics of an object in the image, which mainly includes three functions: 1. goodFeaturesToTrack function Function: extract corners at pixel level in the input image, and support harris corners and Shi Tomasi corners. Function prototype: void goodFeaturesToTrack( InputArray image, OutputArray corne ...

How to install OpenCV on Ubuntu 20.04 OpenCV(Open Source Computer Vision Library) is an open source computer vision library that supports C++, Python, and Java on all major operating systems. It can work with multicore processes and GPU Accelerated for real-time operation. OpenCV is widely used, including medical picture analysis, street view ...

preface opencv part about image drawing 1, Draw graphics Opencv4 provides the circle () function for drawing graphics Drawing a circle: prototype of the circle() function void circle(InputOutputArray img, Point center, int radius, const Scalar & color, int thickness = 1, int lineType = LINE_8, int shift = 0) img: need to draw a ...

preface Image size, flipping and affine transformation in opencv 1, Image size transformation Function prototype: void resize(InputArray src, OutputArray dst, Size dsize, double fx=0, double fy=0, int interpolation = INTER_LINEAR) src: input image dst: output image. The data type of image is the same as src dsize: output image s ...

1. Basic Theory When processing feature descriptors suitable for multiple images, there are two main feature detection methods, one is angle-based detection, the other is to process all areas in the image. Here we will focus on angle-based detection. In 1988, Harris and Stephens presented an angle detection algorithm, HS Angle Detector. See p ...