depthai_setDepthAlign.py

#!/usr/bin/env python3

import cv2
import numpy as np
import depthai as dai
from datetime import timedelta


def getMesh(calibData, camSocket, ispSize):
    M1 = np.array(calibData.getCameraIntrinsics(camSocket, ispSize[0], ispSize[1]))
    d1 = np.array(calibData.getDistortionCoefficients(camSocket))
    R1 = np.identity(3)
    mapX, mapY = cv2.initUndistortRectifyMap(M1, d1, R1, M1, ispSize, cv2.CV_32FC1)

    meshCellSize = 16
    mesh0 = []
    # Creates subsampled mesh which will be loaded on to device to undistort the image
    for y in range(mapX.shape[0] + 1):  # iterating over height of the image
        if y % meshCellSize == 0:
            rowLeft = []
            for x in range(mapX.shape[1]):  # iterating over width of the image
                if x % meshCellSize == 0:
                    if y == mapX.shape[0] and x == mapX.shape[1]:
                        rowLeft.append(mapX[y - 1, x - 1])
                        rowLeft.append(mapY[y - 1, x - 1])
                    elif y == mapX.shape[0]:
                        rowLeft.append(mapX[y - 1, x])
                        rowLeft.append(mapY[y - 1, x])
                    elif x == mapX.shape[1]:
                        rowLeft.append(mapX[y, x - 1])
                        rowLeft.append(mapY[y, x - 1])
                    else:
                        rowLeft.append(mapX[y, x])
                        rowLeft.append(mapY[y, x])
            if (mapX.shape[1] % meshCellSize) % 2 != 0:
                rowLeft.append(0)
                rowLeft.append(0)

            mesh0.append(rowLeft)

    mesh0 = np.array(mesh0)
    meshWidth = mesh0.shape[1] // 2
    meshHeight = mesh0.shape[0]
    mesh0.resize(meshWidth * meshHeight, 2)

    mesh = list(map(tuple, mesh0))

    return mesh, meshWidth, meshHeight


def colorize_depth(depth, max_depth):
    depth = np.clip(depth, 0, max_depth)
    depth = (depth / max_depth * 255).astype(np.uint8)
    return cv2.applyColorMap(depth, cv2.COLORMAP_JET)


def create_device():
    pipeline = dai.Pipeline()
    device = dai.Device()
    calibData = device.readCalibration()

    # RGB camera
    rgb_socket = dai.CameraBoardSocket.CAM_A
    camRgb = pipeline.create(dai.node.ColorCamera)
    camRgb.setBoardSocket(rgb_socket)
    camRgb.setResolution(dai.ColorCameraProperties.SensorResolution.THE_12_MP)
    camRgb.setIspScale(4, 13)  # 1248x936 ~720p

    # Undistortion
    manip = pipeline.create(dai.node.ImageManip)
    mesh, meshWidth, meshHeight = getMesh(calibData, rgb_socket, camRgb.getIspSize())
    manip.setWarpMesh(mesh, meshWidth, meshHeight)
    manip.setMaxOutputFrameSize(camRgb.getIspWidth() * camRgb.getIspHeight() * 3 // 2)
    camRgb.isp.link(manip.inputImage)

    # Left camera
    left = pipeline.create(dai.node.MonoCamera)
    left.setResolution(dai.MonoCameraProperties.SensorResolution.THE_400_P)
    left.setCamera("left")

    # Right camera
    right = pipeline.create(dai.node.MonoCamera)
    right.setResolution(dai.MonoCameraProperties.SensorResolution.THE_400_P)
    right.setCamera("right")

    # Stereo
    stereo = pipeline.create(dai.node.StereoDepth)
    stereo.setDefaultProfilePreset(dai.node.StereoDepth.PresetMode.HIGH_DENSITY)
    stereo.initialConfig.setMedianFilter(dai.MedianFilter.KERNEL_7x7)
    stereo.setLeftRightCheck(True)
    stereo.setDepthAlign(rgb_socket)

    # Synchronization
    sync = pipeline.create(dai.node.Sync)
    sync.setSyncThreshold(timedelta(milliseconds=50))

    # Output
    xoutGrp = pipeline.create(dai.node.XLinkOut)
    xoutGrp.setStreamName("xout")

    # Linking
    left.out.link(stereo.left)
    right.out.link(stereo.right)
    stereo.depth.link(sync.inputs["depth"])
    manip.out.link(sync.inputs["video"])
    sync.out.link(xoutGrp.input)

    return device, pipeline


if __name__ == "__main__":
    device, pipeline = create_device()

    with (device):
        device.startPipeline(pipeline)

        queue = device.getOutputQueue("xout", 10, False)

        cv2.namedWindow("Aligned Depth")
        max_distance = 5  # meters
        while True:

            groupMessage = queue.get()
            depth = groupMessage["depth"].getFrame()
            rgb = groupMessage["video"].getCvFrame()

            colorized = colorize_depth(depth, max_distance * 1000)
            combined = cv2.addWeighted(rgb, 0.5, colorized, 0.8, 0)

            cv2.imshow("Aligned Depth", combined)

            if cv2.waitKey(1) == ord('q'):
                break