使用intelrealsense实时计算aruco marker位姿（Python）

效果图

1.前期准备

1.1.硬件设备

• IntelRealsense D435i

1.2.在线Aruco Marker生成地址

在线生成地址: https://chev.me/arucogen/

根据类型(4x4、5x5、6x6、7x7等)，尺寸，ID去生成Aruco码，点击open另存为PDF或者直接打印

1.3.Aruco Marker信息

4x4指去掉最外一层黑色，内部图像由4x4个正方形组成

2.实现

2.1.Code

intelrealsense内参和畸变系数通过pyrealsense2读取内部信息获取

import pyrealsense2 as rs
import numpy as np
import cv2
# 提示没有aruco的看问题汇总
import cv2.aruco as aruco

# 配置摄像头与开启pipeline
pipeline = rs.pipeline()
config = rs.config()
config.enable_stream(rs.stream.depth, 640, 480, rs.format.z16, 30)
config.enable_stream(rs.stream.color, 640, 480, rs.format.bgr8, 30)
profile = pipeline.start(config)
align_to = rs.stream.color
align = rs.align(align_to)

# 获取对齐的rgb和深度图
def get_aligned_images():
    frames = pipeline.wait_for_frames()
    aligned_frames = align.process(frames)
    aligned_depth_frame = aligned_frames.get_depth_frame()
    color_frame = aligned_frames.get_color_frame()
    # 获取intelrealsense参数
    intr = color_frame.profile.as_video_stream_profile().intrinsics
    # 内参矩阵，转ndarray方便后续opencv直接使用
    intr_matrix = np.array([
        [intr.fx, 0, intr.ppx], [0, intr.fy, intr.ppy], [0, 0, 1]
    ])
    # 深度图-16位
    depth_image = np.asanyarray(aligned_depth_frame.get_data())
    # 深度图-8位
    depth_image_8bit = cv2.convertScaleAbs(depth_image, alpha=0.03)
    pos = np.where(depth_image_8bit == 0)
    depth_image_8bit[pos] = 255
    # rgb图
    color_image = np.asanyarray(color_frame.get_data())
    # return: rgb图，深度图，相机内参，相机畸变系数(intr.coeffs)
    return color_image, depth_image, intr_matrix, np.array(intr.coeffs)


if __name__ == "__main__":
    n = 0
    while 1:
        rgb, depth, intr_matrix, intr_coeffs = get_aligned_images()
        # 获取dictionary, 4x4的码，指示位50个
        aruco_dict = aruco.Dictionary_get(aruco.DICT_4X4_50)
        # 创建detector parameters
        parameters = aruco.DetectorParameters_create()
        # 输入rgb图, aruco的dictionary, 相机内参, 相机的畸变参数
        corners, ids, rejected_img_points = aruco.detectMarkers(rgb, aruco_dict, parameters=parameters,cameraMatrix=intr_matrix, distCoeff=intr_coeffs)
        # 估计出aruco码的位姿，0.045对应markerLength参数，单位是meter
        # rvec是旋转向量， tvec是平移向量
        rvec, tvec, markerPoints = aruco.estimatePoseSingleMarkers(corners, 0.045, intr_matrix, intr_coeffs)
        try:
        	# 在图片上标出aruco码的位置
            aruco.drawDetectedMarkers(rgb, corners)
            # 根据aruco码的位姿标注出对应的xyz轴, 0.05对应length参数，代表xyz轴画出来的长度 
            aruco.drawAxis(rgb, intr_matrix, intr_coeffs, rvec, tvec, 0.05)
            cv2.imshow('RGB image', rgb)
        except:
            cv2.imshow('RGB image', rgb)
        key = cv2.waitKey(1)
        # 按键盘q退出程序
        if key & 0xFF == ord('q') or key == 27:
            pipeline.stop()
            break
        # 按键盘s保存图片
        elif key == ord('s'):
            n = n + 1
            # 保存rgb图
            cv2.imwrite('./img/rgb' + str(n) + '.jpg', rgb)

    cv2.destroyAllWindows()

问题汇总

1. 提示cv2没有aruco这个参数
   cv2.aruco在opencv-contrib-python这个版本的opencv，但可能会跟opencv-python的包名冲突。

pip uninstall opencv-python
pip uninstall opencv-contrib-python
pip install opencv-contrib-python