add erosion_dilation

data/1.OpenCV初阶/2.二值图像处理/2.腐蚀与膨胀/erosion_dilation.md

+# 普通鸬鹚不普通
+
+OpenCV的膨胀与腐蚀，让“普通鸬鹚”不普通，下图从左到右分别是：
+
+* 原图
+* 原图经过膨胀得到的图
+* 原图经过腐蚀得到的图
+
+![](./bird_erosion_dilation.jpeg)
+
+下面对腐蚀和膨胀实现代码正确的是？
+
+
+## 答案
+
+```python
+import numpy as np
+import cv2
+
+if __name__ == '__main__':
+    img_origin = cv2.imread('bird.jpeg', cv2.COLOR_BGR2LAB)
+
+    kernel = np.ones((3, 3), np.uint8)
+    img_erosion = cv2.erode(img_origin, kernel, iterations=1)
+    img_dilation = cv2.dilate(img_origin, kernel, iterations=1)
+
+    img_all = np.concatenate((img_origin, img_erosion, img_dilation), axis=1)
+    cv2.imshow('img: origin, erosion and dilation', img_all)
+
+    cv2.waitKey(0)
+    cv2.destroyAllWindows()
+```
+
+## 选项
+
+### 没有使用核函数
+
+```python
+import numpy as np
+import cv2
+
+if __name__ == '__main__':
+    img_origin = cv2.imread('bird.jpeg', cv2.COLOR_BGR2LAB)
+
+    img_erosion = cv2.erode(img_origin, iterations=1)
+    img_dilation = cv2.dilate(img_origin, iterations=1)
+
+    img_all = np.concatenate((img_origin, img_erosion, img_dilation), axis=1)
+    cv2.imshow('img: origin, erosion and dilation', img_all)
+
+    cv2.waitKey(0)
+    cv2.destroyAllWindows()
+```
+
+### 参数顺序不对
+
+```python
+import numpy as np
+import cv2
+
+if __name__ == '__main__':
+    img_origin = cv2.imread('bird.jpeg', cv2.COLOR_BGR2LAB)
+
+    kernel = np.ones((3, 3), np.uint8)
+    img_erosion = cv2.erode(kernel, img_origin, iterations=1)
+    img_dilation = cv2.dilate(kernel, img_origin, iterations=1)
+
+    img_all = np.concatenate((img_origin, img_erosion, img_dilation), axis=1)
+    cv2.imshow('img: origin, erosion and dilation', img_all)
+
+    cv2.waitKey(0)
+    cv2.destroyAllWindows()
+```
+
+### 顺序反了
+
+```python
+import numpy as np
+import cv2
+
+if __name__ == '__main__':
+    img_origin = cv2.imread('bird.jpeg', cv2.COLOR_BGR2LAB)
+
+    kernel = np.ones((3, 3), np.uint8)
+    img_erosion = cv2.dilate(img_origin, kernel, iterations=1)
+    img_dilation = cv2.erode(img_origin, kernel, iterations=1)
+
+    img_all = np.concatenate((img_origin, img_erosion, img_dilation), axis=1)
+    cv2.imshow('img: origin, erosion and dilation', img_all)
+
+    cv2.waitKey(0)
+    cv2.destroyAllWindows()
+```

data/1.OpenCV初阶/2.二值图像处理/2.腐蚀与膨胀/erosion_dilation.py

+import numpy as np
+import cv2
+
+if __name__ == '__main__':
+    img_origin = cv2.imread('bird.jpeg', cv2.COLOR_BGR2LAB)
+
+    kernel = np.ones((3, 3), np.uint8)
+    img_erosion = cv2.erode(img_origin, kernel, iterations=1)
+    img_dilation = cv2.dilate(img_origin, kernel, iterations=1)
+
+    img_all = np.concatenate((img_origin, img_erosion, img_dilation), axis=1)
+    cv2.imwrite('bird_erosion_dilation.jpeg', img_all)
+    cv2.imshow('img: origin, erosion and dilation', img_all)
+
+    cv2.waitKey(0)
+    cv2.destroyAllWindows()