Finding rotation angle inside a license plate
我正在尝试纠正牌照内的变形，例如：
。
然而，我找不到一个强有力的方法来检测旋转角度。我试着用特征值，但是失败了。
我也在考虑霍夫线检测，但结果仍然很差。
如何改进旋转检测？
找板轮廓，用
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 | #preprocessing steps ... #find angle im2, contours, hierarchy = cv2.findContours(preprocessed_sloping_plate,cv2.RETR_TREE,cv2.CHAIN_APPROX_SIMPLE) #contour with the largest area is possibly the plate max_area = 0 max_cnt = None for cnt in contours: area = cv2.contourArea(cnt) if(area > max_area): max_area = area max_cnt = cnt min_rect = cv2.minAreaRect(max_cnt) (x,y,w,h,angle) = min_rect #rotate M = cv2.getRotationMatrix2D((w/2, h/2), angle, 1.0) rotated_plate = cv2.warpAffine(preprocessed_sloping_plate, M, (w,h)) |