OpenCV - Drawing a Circle with python

In this tutorial, I will show you how to draw a circle in OpenCV.

OpenCV comes with lots of built-in functions that make our life easier especially when we are working on image processing.

And there is a function called circle in OpenCV which is used to draw a circle.

This function takes following parameters:

1. Image: Takes an image object
2. Center: Center point coordinates
3. Radius: Radius of the circle
4. Color: Takes color in BGR format
5. Thickness: By default set to 1 (optional)
6. Line Type: By default set to 8-connected.It can also be LINE_AA or 4-connected (Optional)
7. Shift: Shifts fractional bits in the point coordinates of center and radius (Optional)

Especially when we are creating closed shapes. Thickness plays an important role. Here if the negative thickness is passed in this function or any other function which creates a closed shape(rectangle, polygon, etc). Then it creates a filled shape (filled with color).

Negative Thickness

Positive Thickness

Anti Aliased Circle

Program

#import cv2 moduleimport cv2 as cvimg = cv.imread("nature.jpg")height,width= img.shape[0:2]#Hollow Circleimg = cv.circle(img,(width/2,height/2),100,(255,145,88),10)#Filled Circle#img = cv.circle(img,(width/2,height/2),100,(255,145,88),-1)#AntiAliased Curve#img = cv.circle(img,(width/2,height/2),250,(255,145,88),10,cv.LINE_AA)cv.imshow('Circle',img)cv.waitKey(0)cv.destroyAllWindows()

Thanks for reading 🙂 🙂

Comments

Automation - Update Naukri Profile Using Selenium

Recently one of my friend came to me with a problem. He is looking out for new job but he feels quite boring to update his profile on daily basis. As some people says updating profile in the morning gives you more calls as it keeps the newly updated profile on top (Although i don’t know whether naukri works this way or not 😀 ). As i was more interested to solve his problem. After listening his problem i came to solution that instead of updating it manually lets make this job automatic. And it is quite interesting how we can automate our daily boring task with automation. Another day i came with the solution . And the solution was to make it automatic using selenium (Those who are not aware about selenium do check this link) In short, Selenium is a Testing automation Framework. And it is for automating web applications for testing purposes, but is certainly not limited to just that. Boring web-based administration tasks can (and should) also be automated as well....

Shut Down the Computer using notepad

Open notepad >> Write @echo off msg * I am tired. shutdown -c “So, Bye Bye dear” -s >> Save the File as AnyName.bat When you will open this file, your Computer will Shut down on its own after showing the message in it. NOTE: FOR EDUCATIONAL PURPOSE ONLY.I AM NOT RESPONSIBLE FOR IF ANYTHING GOES WRONG….

Android - Show A Dialog From Service

In this article, I will be discussing how you can create a dialog from service. As we all know that service in android does not have any UI and it is intended for long-running background tasks. But sometimes it is required to show some information to the user when your app is running in the background. Today I will show you how you can implement this type of functionality in your application. Before starting the tutorial let me tell you about the special permission that we are going to use. Permission AndroidManifest.xml<uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW"/> This permission allows the app to use the system level window. AndroidManifest.xml <?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.app.dialogfromservice"> <uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW"/> <appl...

Technical Tips N Tricks

Search This Blog