## Basic geometric transformations – OpenCV 3.4 with python 3 Tutorial 12

[python] import cv2 import numpy as np img = cv2.imread("red_panda.jpg") rows, cols, ch = img.shape print("Height: ", rows) print("Width: ", cols) scaled_img = cv2.resize(img, None, fx=1/2, fy=1/2) matrix_t = np.float32([[1, 0, -100], [0, 1, -30]]) translated_img = cv2.warpAffine(img, matrix_t, (cols, rows)) matrix_r = cv2.getRotationMatrix2D((cols/2, rows/2),…

## Histograms – OpenCV 3.4 with python 3 Tutorial 11

Source code: [python] import cv2 import numpy as np from matplotlib import pyplot as plt img = cv2.imread("sea_beach.jpg") b, g, r = cv2.split(img) cv2.imshow("img", img) cv2.imshow("b", b) cv2.imshow("g", g) cv2.imshow("r", r) plt.hist(b.ravel(), 256, [0, 256]) plt.hist(g.ravel(), 256, [0, 256]) plt.hist(r.ravel(), 256, [0, 256]) plt.show() [/python]…

## Basic Thresholding – OpenCV 3.4 with python 3 Tutorial 10

Threshold: [python] import cv2 import numpy as np img = cv2.imread("black_to_white.jpeg", cv2.IMREAD_GRAYSCALE) _, threshold_binary = cv2.threshold(img, 128, 255, cv2.THRESH_BINARY) _, threshold_binary_inv = cv2.threshold(img, 128, 255, cv2.THRESH_BINARY_INV) _, threshold_trunc = cv2.threshold(img, 128, 255, cv2.THRESH_TRUNC) _, threshold_to_zero = cv2.threshold(img, 12, 255, cv2.THRESH_TOZERO) cv2.imshow("Image", img) cv2.imshow("th binary", threshold_binary)…

## Object detection using HSV Color space – OpenCV 3.4 with python 3 Tutorial 9

What we will learn in this tutorial: What is HSV How to object recognition by color works What is HSV HSV (Hue Saturation Value) is a color format that describes colors in terms of their shade (saturation) and brightness (value).  How to object recognition by…

## Trackbars – OpenCV 3.4 with python 3 Tutorial 8

Source code: [python] import cv2 import numpy as np def nothing(x): pass cap = cv2.VideoCapture(0) cv2.namedWindow("frame") cv2.createTrackbar("test", "frame", 50, 500, nothing) cv2.createTrackbar("color/gray", "frame", 0, 1, nothing) while True: _, frame = cap.read() test = cv2.getTrackbarPos("test", "frame") font = cv2.FONT_HERSHEY_COMPLEX cv2.putText(frame, str(test), (50, 150), font, 4,…

## Bitwise Operators – OpenCV 3.4 with python 3 Tutorial 7

Source code: [python] import cv2 import numpy as np img1 = cv2.imread("drawing_1.png") img2 = cv2.imread("drawing_2.png") bit_and = cv2.bitwise_and(img2, img1) bit_or = cv2.bitwise_or(img2, img1) bit_xor = cv2.bitwise_xor(img1, img2) bit_not = cv2.bitwise_not(img1) bit_not2 = cv2.bitwise_not(img2) cv2.imshow("img1", img1) cv2.imshow("img2", img2) cv2.imshow("bit_and", bit_and) cv2.imshow("bit_or", bit_or) cv2.imshow("bit_xor", bit_xor) cv2.imshow("bit_not", bit_not)…