added edge detection tutorial

x4nth055 · x4nth055 · commit 65cd7b5e9b5f · 2019-10-10T17:44:06.000+02:00
diff --git a/README.md b/README.md
@@ -28,7 +28,9 @@ This is a repository of all the tutorials of [The Python Code](https://www.thepy
     - [Building a Speech Emotion Recognizer using Scikit-learn](https://www.thepythoncode.com/article/building-a-speech-emotion-recognizer-using-sklearn). ([code](machine-learning/speech-emotion-recognition))
     - [How to Make an Image Classifier in Python using Keras](https://www.thepythoncode.com/article/image-classification-keras-python). ([code](machine-learning/image-classifier))
     - [How to Use Transfer Learning for Image Classification using Keras in Python](https://www.thepythoncode.com/article/use-transfer-learning-for-image-flower-classification-keras-python). ([code](machine-learning/image-classifier-using-transfer-learning))
+    - [How to Perform Edge Detection in Python using OpenCV](https://www.thepythoncode.com/article/canny-edge-detection-opencv-python). ([code](machine-learning/edge-detection))
     - [Top 8 Python Libraries For Data Scientists and Machine Learning Engineers](https://www.thepythoncode.com/article/top-python-libraries-for-data-scientists).
+    
 
 - ### [General Python Topics](https://www.thepythoncode.com/topic/general-python-topics)
     - [How to Make Facebook Messenger bot in Python](https://www.thepythoncode.com/article/make-bot-fbchat-python). ([code](general/messenger-bot))
diff --git a/machine-learning/edge-detection/README.md b/machine-learning/edge-detection/README.md
@@ -0,0 +1,11 @@
+# [How to Perform Edge Detection in Python using OpenCV](https://www.thepythoncode.com/article/canny-edge-detection-opencv-python)
+To run this:
+- `pip3 install -r requirements.txt`
+- To detect edges of a specific image (`little_flower.jpg`):
+    ```
+    python edge_detector.py little_flower.jpg
+    ```
+- To detect edges live using your webcam:
+    ```
+    python live_edge_detector.py
+    ```
diff --git a/machine-learning/edge-detection/edge_detector.py b/machine-learning/edge-detection/edge_detector.py
@@ -0,0 +1,21 @@
+import cv2
+import numpy as np
+import matplotlib.pyplot as plt
+import sys
+
+# read the image
+image = cv2.imread(sys.argv[1])
+
+# convert it to grayscale
+gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
+
+# show the grayscale image, if you want to show, uncomment 2 below lines
+# plt.imshow(gray, cmap="gray")
+# plt.show()
+
+# perform the canny edge detector to detect image edges
+edges = cv2.Canny(gray, threshold1=30, threshold2=100)
+
+# show the detected edges
+plt.imshow(edges, cmap="gray")
+plt.show()
diff --git a/machine-learning/edge-detection/little_flower.jpg b/machine-learning/edge-detection/little_flower.jpg
diff --git a/machine-learning/edge-detection/live_edge_detector.py b/machine-learning/edge-detection/live_edge_detector.py
@@ -0,0 +1,16 @@
+import numpy as np
+import cv2
+
+cap = cv2.VideoCapture(0)
+
+while True:
+    _, frame = cap.read()
+    gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
+    edges = cv2.Canny(gray, 30, 100)
+    cv2.imshow("edges", edges)
+    cv2.imshow("gray", gray)
+    if cv2.waitKey(1) == ord("q"):
+        break
+
+cap.release()
+cv2.destroyAllWindows()
diff --git a/machine-learning/edge-detection/requirements.txt b/machine-learning/edge-detection/requirements.txt
@@ -0,0 +1,3 @@
+opencv-python
+numpy
+matplotlib

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,3 @@`
	`1`	`+opencv-python`
	`2`	`+numpy`
	`3`	`+matplotlib`