import cv2
import numpy as np

blur = 3
canny_low = 255
canny_high = 50

def on_change(value):
    pass

img = cv2.imread("./res/trees/berk_sq1_original.png")
img = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)

width = int(img.shape[1] * 40 / 100)
height = int(img.shape[0] * 40 / 100)
dim = (width, height)

# resize image
img = cv2.resize(img, dim, interpolation = cv2.INTER_AREA)

cv2.imshow('frame', img)

cv2.createTrackbar('Contrast', 'frame', 0, 25, on_change)
cv2.createTrackbar('Canny low', 'frame', 0, 1000, on_change)
cv2.createTrackbar('Canny high', 'frame', 0, 1000, on_change)

while(1):
    # get data from trackbars
    blur = cv2.getTrackbarPos('Blur rate', 'frame')
    canny_low = cv2.getTrackbarPos('Canny low', 'frame')
    canny_high = cv2.getTrackbarPos('Canny high', 'frame')

    # Canny Edge Detection
    edges = cv2.Canny(image=img, threshold1=canny_low, threshold2=canny_high)  
    
    # Display Canny Edge Detection Image
    cv2.imshow("Canny Edge Detection", edges)

    # wait for escape
    k = cv2.waitKey(5) & 0xFF
    if k == 27:
        break

cv2.destroyAllWindows()