How do you calculate ROI on OpenCV?

How do you calculate ROI on OpenCV?

Selecting Single ROI bounding Box in OpenCV [python].Import the necessary libraries. import cv2. Read the image by using imread function. Pass the image in SelectROI function. save the selected rectangle point (roi) in a variable. Use the rectangle points to crop. Display the Cropped ROI. Save the cropped ROI.

What is contour area in OpenCV?

Contours can be explained simply as a curve joining all the continuous points (along the boundary), having same color or intensity. The contours are a useful tool for shape analysis and object detection and recognition. In OpenCV, finding contours is like finding white object from black background.

Where is the largest contour on OpenCV?

1 Answer. You can start by defining a mask in the range of the red tones of the book you are looking for. Then you can just find the contour with the biggest area and draw the rectangular shape of the book. If you want the book to rotate you can use rect = cv2.

What can I do with open CV?

What can you do with OpenCV?In-built data structures and input/output. Image processing operations. Building GUI. Video analysis. 3D reconstruction. Feature extraction. Object detection. Machine learning.

How do I use OpenCV in Python?

Download latest OpenCV release from sourceforge site and double-click to extract it.Goto opencv/build/python/2.7 folder.Copy cv2. pyd to C:/Python27/lib/site-packeges.Open Python IDLE and type following codes in Python terminal. >>> import cv2 >>> print cv2. __version__