OpenCV Basics

Install OpenCV
pip install opencv-python

Import
import cv2
import numpy as np

Read image
img = cv2.imread("image.jpg")

Read in grayscale
img = cv2.imread("image.jpg", cv2.IMREAD_GRAYSCALE)

Display image
cv2.imshow("Image", img)
cv2.waitKey(0)
cv2.destroyAllWindows()

Save image
cv2.imwrite("output.jpg", img)

Get dimensions
height, width, channels = img.shape

Resize image
resized = cv2.resize(img, (500, 300))

Rotate image
rotated = cv2.rotate(img, cv2.ROTATE_90_CLOCKWISE)

Crop image
cropped = img[100:400, 200:600]

BGR to RGB
rgb = cv2.cvtColor(img, cv2.COLOR_BGR2RGB)

BGR to grayscale
gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)

BGR to HSV
hsv = cv2.cvtColor(img, cv2.COLOR_BGR2HSV)