[python][原创]opencv截取图像写字画矩形框

之前每次用都忘了，这次记录下来，备份一下免得自己到处找。

抠图：左上角坐标(xmin,ymin),右下角坐标(xmax,ymax)

     save_image = img[ymin:ymax, xmin:xmax]

#用 OpenCV 标注 bounding box主要用到下面两个工具——cv2.rectangle() 和 cv2.putText()。用法如下： # cv2.rectangle() # 输入参数分别为图像、左上角坐标、右下角坐标、颜色数组、粗细 cv2.rectangle(img, (x,y), (x+w,y+h), (B,G,R), Thickness)

# cv2.putText() # 输入参数为图像、文本、位置、字体、大小、颜色数组、粗细 cv2.putText(img, text, (x,y), Font, Size, (B,G,R), Thickness)

#举例：

import cv2 imgName = '001.jpg' img = cv2.imread(imgName) # 画矩形框 cv2.rectangle(img, (10,20), (50,60), (0,255,0), 4)

# 标注文本 font = cv2.FONT_HERSHEY_SUPLEX text = '001' cv2.putText(img, text, (100, 100), font, 2, (0,0,255), 1) cv2.imwrite('new.jpg', img) 其中字体可以选择： FONT_HERSHEY_SIMPLEX Python: cv.FONT_HERSHEY_SIMPLEX normal size sans-serif font

FONT_HERSHEY_PLAIN Python: cv.FONT_HERSHEY_PLAIN small size sans-serif font

FONT_HERSHEY_DUPLEX Python: cv.FONT_HERSHEY_DUPLEX normal size sans-serif font (more complex than FONT_HERSHEY_SIMPLEX)

FONT_HERSHEY_COMPLEX Python: cv.FONT_HERSHEY_COMPLEX normal size serif font

FONT_HERSHEY_TRIPLEX Python: cv.FONT_HERSHEY_TRIPLEX normal size serif font (more complex than FONT_HERSHEY_COMPLEX)

FONT_HERSHEY_COMPLEX_SMALL Python: cv.FONT_HERSHEY_COMPLEX_SMALL smaller version of FONT_HERSHEY_COMPLEX

FONT_HERSHEY_SCRIPT_SIMPLEX Python: cv.FONT_HERSHEY_SCRIPT_SIMPLEX hand-writing style font

FONT_HERSHEY_SCRIPT_COMPLEX Python: cv.FONT_HERSHEY_SCRIPT_COMPLEX more complex variant of FONT_HERSHEY_SCRIPT_SIMPLEX

FONT_ITALIC Python: cv.FONT_ITALIC flag for italic font

字体大小：数值越大，字体越大 字体粗细：越大越粗，数值表示描绘的线条占有的直径像素个数