CV tutorial

Canny

# CannyStill.py

import cv3
import numpy as np
import os

###################################################################################################
def main():
    imgOriginal = cv3.imread("image.jpg")               # open image

    if imgOriginal is None:                             # if image was not read successfully
        print("error: image not read from file \n\n")       # print error message to std out
        os.system("pause")                                  # pause so user can see error message
        return                                              # and exit function (which exits program)
    
    imgGrayscale = cv3.cvtColor(imgOriginal, cv3.COLOR_BGR2GRAY)        # convert to grayscale

    imgBlurred = cv3.GaussianBlur(imgGrayscale, (5, 5), 0)              # blur
    
    imgCanny = cv3.Canny(imgBlurred, 100, 200)                          # get Canny edges

    cv3.namedWindow("imgOriginal", cv3.WINDOW_AUTOSIZE)        # create windows, use WINDOW_AUTOSIZE for a fixed window size
    cv3.namedWindow("imgCanny", cv3.WINDOW_AUTOSIZE)           # or use WINDOW_NORMAL to allow window resizing

    cv3.imshow("imgOriginal", imgOriginal)         # show windows
    cv3.imshow("imgCanny", imgCanny)

    cv3.waitKey()                               # hold windows open until user presses a key

    cv3.destroyAllWindows()                     # remove windows from memory

    return

###################################################################################################
if __name__ == "__main__":
    main()