Python opencv realizes license plate recognition color positioning
The main code reference https://blog.csdn.net/wzh191920/article/details/79589506
GitHub：https://github.com/yinghualuowu
We found that some pictures are simply positioned randomly because the preprocessing is not done well. If we don’t want to move the preprocessing code, we will change the method.
This is the approximate range of yellow and blue that I have been looking for for a long time
lower_blue = np.array([100, 110, 110])
upper_blue = np.array([130, 255, 255])
lower_yellow = np.array([15, 55, 55])
upper_yellow = np.array([50, 255, 255])Filter the color~
hsv = cv2.cvtColor(filename, cv2.COLOR_BGR2HSV)
mask_blue = cv2.inRange(hsv, lower_blue, upper_blue)
mask_yellow = cv2.inRange(hsv, lower_yellow, upper_yellow)
output = cv2.bitwise_and(hsv, hsv, mask=mask_blue+mask_yellow)
# 根据阈值找到对应颜色
output = cv2.cvtColor(output, cv2.COLOR_BGR2GRAY)It feels good, at least one can be seen.
Let’s do a little pre-processing opening and closing operation to paste the white area into one piece, hahahaha, it’s ok
Matrix = np.ones((20, 20), np.uint8)
img_edge1 = cv2.morphologyEx(output, cv2.MORPH_CLOSE, Matrix)
img_edge2 = cv2.morphologyEx(img_edge1, cv2.MORPH_OPEN, Matrix)
Then use it to find the rectangle~~~ I found it
Don't look for cars with similar colors to the license plate! ! ! ! ! !
