Add Java and Python code for the following imgproc tutorials: Canny, Remap, threshold and threshold inRange. Use HSV colorspace instead of RGB for inRange threshold tutorial.

samples/python/tutorial_code/ImgTrans/canny_detector/CannyDetector_Demo.py

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+from __future__ import print_function
+import cv2 as cv
+import argparse
+
+max_lowThreshold = 100
+window_name = 'Edge Map'
+title_trackbar = 'Min Threshold:'
+ratio = 3
+kernel_size = 3
+
+def CannyThreshold(val):
+    low_threshold = val
+    img_blur = cv.blur(src_gray, (3,3))
+    detected_edges = cv.Canny(img_blur, low_threshold, low_threshold*ratio, kernel_size)
+    mask = detected_edges != 0
+    dst = src * (mask[:,:,None].astype(src.dtype))
+    cv.imshow(window_name, dst)
+
+parser = argparse.ArgumentParser(description='Code for Canny Edge Detector tutorial.')
+parser.add_argument('--input', help='Path to input image.', default='../data/fruits.jpg')
+args = parser.parse_args()
+
+src = cv.imread(args.input)
+if src is None:
+    print('Could not open or find the image: ', args.input)
+    exit(0)
+
+src_gray = cv.cvtColor(src, cv.COLOR_BGR2GRAY)
+
+cv.namedWindow(window_name)
+cv.createTrackbar(title_trackbar, window_name , 0, max_lowThreshold, CannyThreshold)
+
+CannyThreshold(0)
+cv.waitKey()