Python学习记录(六)：opencv-python
一、安装
pip install opencv-python
二、图像读写
cv2.imread(path, flag)返回值类型：np.ndarraycv2.imwrite(filename, image)
三、图像编辑
cv2.resize()图像缩放，默认方式为cv2.INTER_LINEAR（双线性插值）cv2.flip()图像翻转cv2.rotate()图像旋转
四、常用绘图
cv2.rectangle(image, start_point, end_point, color, thickness)start_point: 左上，end_point：右下cv2.circle(image, center_coordinates, radius, color, thickness)center_coordinates：中心点，radius：半径；The coordinates are represented as tuples of two values i.e. (X coordinate value, Y coordinate value)cv2.putText(image, text, org, font, fontScale, color[, thickness[, lineType[, bottomLeftOrigin]]])cv2.line(image, start_point, end_point, color, thickness)cv2.arrowedLine(image, start_point, end_point, color, thickness)cv2.polylines(image, [pts], isClosed, color, thickness)用于在图像上绘制多边形；参数isClosed: Flag indicating whether the drawn polylines are closed or not. If they are closed, the function draws a line from the last vertex of each curve to its first vertex.（即所绘制的多边形是否闭合）
五、视频读写
cv2.VideoCapture()cv2.VideoWriter(filename, fourcc, fps, frameSize)
