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

@@ -0,0 +1,34 @@
+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()

samples/python/tutorial_code/ImgTrans/remap/Remap_Demo.py

@@ -0,0 +1,65 @@
+from __future__ import print_function
+import cv2 as cv
+import numpy as np
+import argparse
+
+## [Update]
+def update_map(ind, map_x, map_y):
+    if ind == 0:
+        for i in range(map_x.shape[0]):
+            for j in range(map_x.shape[1]):
+                if j > map_x.shape[1]*0.25 and j < map_x.shape[1]*0.75 and i > map_x.shape[0]*0.25 and i < map_x.shape[0]*0.75:
+                    map_x[i,j] = 2 * (j-map_x.shape[1]*0.25) + 0.5
+                    map_y[i,j] = 2 * (i-map_y.shape[0]*0.25) + 0.5
+                else:
+                    map_x[i,j] = 0
+                    map_y[i,j] = 0
+    elif ind == 1:
+        for i in range(map_x.shape[0]):
+            map_x[i,:] = [x for x in range(map_x.shape[1])]
+        for j in range(map_y.shape[1]):
+            map_y[:,j] = [map_y.shape[0]-y for y in range(map_y.shape[0])]
+    elif ind == 2:
+        for i in range(map_x.shape[0]):
+            map_x[i,:] = [map_x.shape[1]-x for x in range(map_x.shape[1])]
+        for j in range(map_y.shape[1]):
+            map_y[:,j] = [y for y in range(map_y.shape[0])]
+    elif ind == 3:
+        for i in range(map_x.shape[0]):
+            map_x[i,:] = [map_x.shape[1]-x for x in range(map_x.shape[1])]
+        for j in range(map_y.shape[1]):
+            map_y[:,j] = [map_y.shape[0]-y for y in range(map_y.shape[0])]
+## [Update]
+
+parser = argparse.ArgumentParser(description='Code for Remapping tutorial.')
+parser.add_argument('--input', help='Path to input image.', default='../data/chicky_512.png')
+args = parser.parse_args()
+
+## [Load]
+src = cv.imread(args.input, cv.IMREAD_COLOR)
+if src is None:
+    print('Could not open or find the image: ', args.input)
+    exit(0)
+## [Load]
+
+## [Create]
+map_x = np.zeros((src.shape[0], src.shape[1]), dtype=np.float32)
+map_y = np.zeros((src.shape[0], src.shape[1]), dtype=np.float32)
+## [Create]
+
+## [Window]
+window_name = 'Remap demo'
+cv.namedWindow(window_name)
+## [Window]
+
+## [Loop]
+ind = 0
+while True:
+    update_map(ind, map_x, map_y)
+    ind = (ind + 1) % 4
+    dst = cv.remap(src, map_x, map_y, cv.INTER_LINEAR)
+    cv.imshow(window_name, dst)
+    c = cv.waitKey(1000)
+    if c == 27:
+        break
+## [Loop]