contours

import cv2

def find_curved_contour(img):
    # Convert image to hsv colour space
    img_hsv = cv2.cvtColor(img, cv2.COLOR_BGR2HSV)
    # cv2.imshow("hsv", img_hsv)
    # cv2.waitKey(1000)

    # Apply threshold to filter out the red background
    thresh_min = (100, 0.000, 0.000)
    thresh_max = (109, 255, 255)
    thresh_img = cv2.inRange(img_hsv, thresh_min, thresh_max)
    cv2.imshow("thresh", thresh_img)
    cv2.waitKey(1000)

    # Find contours
    _, contours, hierarchy = cv2.findContours(thresh_img, cv2.RETR_TREE, cv2.CHAIN_APPROX_NONE)

    # Display the contour with the biggest area
    if contours is not None and len(contours) > 0:
        contour = max(contours, key=cv2.contourArea)
        cv2.drawContours(img, contour, -1, (0,255,0), 2)

        cv2.imshow("contour", img)
        cv2.waitKey(10000)


if __name__ == '__main__':
    img_path = "/home/jarod/Pictures/curved_image.png"
    img = cv2.imread(img_path)
    cv2.imshow("raw", img)
    cv2.waitKey(1000)

    # Find contours
    find_curved_contour(img)