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  • Spatial detections on rotated OAK
  • Similar samples:
  • Setup
  • Source code

Spatial detections on rotated OAK

This example is very similar to RGB & MobilenetSSD with spatial data - it only assumes we have OAK rotated by 180° (upside down)ColorCamera frames are rotated on the sensor itself, by setting camRgb.setImageOrientation(dai.CameraImageOrientation.ROTATE_180_DEG). This means all outputs from the node (still/isp/video/preview) will already be rotated.We rotate depth frames after the StereoDepth creates them. One might try rotating mono frames before sending them to the StereoDepth node, but this wouldn't work as stereo calibration would need to reflect such changes. So we use the ImageManip node to rotate depth (code below) and then send it to the MobileNetSpatialDetectionNetwork.
Command Line
1manip = pipeline.createImageManip()
2    # Vertical + Horizontal flip == rotate frame for 180°
3    manip.initialConfig.setVerticalFlip(True)
4    manip.initialConfig.setHorizontalFlip(True)
5    manip.setFrameType(dai.ImgFrame.Type.RAW16)
6    stereo.depth.link(manip.inputImage)
MobileNetSpatialDetectionNetwork node then receives correctly rotated color and depth frame, which results in correct spatial detection output.

Similar samples:

Setup

Please run the install script to download all required dependencies. Please note that this script must be ran from git context, so you have to download the depthai-python repository first and then run the script
Command Line
1git clone https://github.com/luxonis/depthai-python.git
2cd depthai-python/examples
3python3 install_requirements.py
For additional information, please follow the installation guide.

Source code

Python
C++
Python
GitHub
1#!/usr/bin/env python3
2
3from pathlib import Path
4import sys
5import cv2
6import depthai as dai
7import numpy as np
8'''
9Spatial object detections demo for 180° rotated OAK camera.
10'''
11
12# Get argument first
13nnBlobPath = str((Path(__file__).parent / Path('../models/mobilenet-ssd_openvino_2021.4_6shave.blob')).resolve().absolute())
14if len(sys.argv) > 1:
15    nnBlobPath = sys.argv[1]
16
17if not Path(nnBlobPath).exists():
18    import sys
19    raise FileNotFoundError(f'Required file/s not found, please run "{sys.executable} install_requirements.py"')
20
21# MobilenetSSD label texts
22labelMap = ["background", "aeroplane", "bicycle", "bird", "boat", "bottle", "bus", "car", "cat", "chair", "cow",
23            "diningtable", "dog", "horse", "motorbike", "person", "pottedplant", "sheep", "sofa", "train", "tvmonitor"]
24
25syncNN = True
26
27# Create pipeline
28pipeline = dai.Pipeline()
29
30# Define sources and outputs
31camRgb = pipeline.createColorCamera()
32spatialDetectionNetwork = pipeline.create(dai.node.MobileNetSpatialDetectionNetwork)
33monoLeft = pipeline.create(dai.node.MonoCamera)
34monoRight = pipeline.create(dai.node.MonoCamera)
35stereo = pipeline.create(dai.node.StereoDepth)
36
37xoutRgb = pipeline.create(dai.node.XLinkOut)
38xoutNN = pipeline.create(dai.node.XLinkOut)
39xoutDepth = pipeline.create(dai.node.XLinkOut)
40
41xoutRgb.setStreamName("rgb")
42xoutNN.setStreamName("detections")
43xoutDepth.setStreamName("depth")
44
45# Properties
46camRgb.setPreviewSize(300, 300)
47camRgb.setResolution(dai.ColorCameraProperties.SensorResolution.THE_1080_P)
48camRgb.setInterleaved(False)
49camRgb.setColorOrder(dai.ColorCameraProperties.ColorOrder.BGR)
50camRgb.setImageOrientation(dai.CameraImageOrientation.ROTATE_180_DEG)
51
52monoLeft.setResolution(dai.MonoCameraProperties.SensorResolution.THE_400_P)
53monoLeft.setCamera("left")
54monoRight.setResolution(dai.MonoCameraProperties.SensorResolution.THE_400_P)
55monoRight.setCamera("right")
56
57# Setting node configs
58stereo.setDefaultProfilePreset(dai.node.StereoDepth.PresetMode.HIGH_DENSITY)
59# Align depth map to the perspective of RGB camera, on which inference is done
60stereo.setDepthAlign(dai.CameraBoardSocket.CAM_A)
61stereo.setSubpixel(True)
62stereo.setOutputSize(monoLeft.getResolutionWidth(), monoLeft.getResolutionHeight())
63
64rotate_stereo_manip = pipeline.createImageManip()
65rotate_stereo_manip.initialConfig.setVerticalFlip(True)
66rotate_stereo_manip.initialConfig.setHorizontalFlip(True)
67rotate_stereo_manip.setFrameType(dai.ImgFrame.Type.RAW16)
68stereo.depth.link(rotate_stereo_manip.inputImage)
69
70spatialDetectionNetwork.setBlobPath(nnBlobPath)
71spatialDetectionNetwork.setConfidenceThreshold(0.5)
72spatialDetectionNetwork.input.setBlocking(False)
73spatialDetectionNetwork.setBoundingBoxScaleFactor(0.5)
74spatialDetectionNetwork.setDepthLowerThreshold(100)
75spatialDetectionNetwork.setDepthUpperThreshold(5000)
76
77# Linking
78monoLeft.out.link(stereo.left)
79monoRight.out.link(stereo.right)
80
81camRgb.preview.link(spatialDetectionNetwork.input)
82if syncNN:
83    spatialDetectionNetwork.passthrough.link(xoutRgb.input)
84else:
85    camRgb.preview.link(xoutRgb.input)
86
87spatialDetectionNetwork.out.link(xoutNN.input)
88
89rotate_stereo_manip.out.link(spatialDetectionNetwork.inputDepth)
90spatialDetectionNetwork.passthroughDepth.link(xoutDepth.input)
91color = (255, 0, 0)
92# Connect to device and start pipeline
93with dai.Device(pipeline) as device:
94
95    # Output queues will be used to get the rgb frames and nn data from the outputs defined above
96    previewQueue = device.getOutputQueue(name="rgb", maxSize=4, blocking=False)
97    detectionNNQueue = device.getOutputQueue(name="detections", maxSize=4, blocking=False)
98    depthQueue = device.getOutputQueue(name="depth", maxSize=4, blocking=False)
99
100    while True:
101        inPreview = previewQueue.get()
102        inDet = detectionNNQueue.get()
103        depth = depthQueue.get()
104
105        frame = inPreview.getCvFrame()
106        depthFrame = depth.getFrame() # depthFrame values are in millimeters
107
108        depth_downscaled = depthFrame[::4]
109        if np.all(depth_downscaled == 0):
110            min_depth = 0  # Set a default minimum depth value when all elements are zero
111        else:
112            min_depth = np.percentile(depth_downscaled[depth_downscaled != 0], 1)
113        max_depth = np.percentile(depth_downscaled, 99)
114        depthFrameColor = np.interp(depthFrame, (min_depth, max_depth), (0, 255)).astype(np.uint8)
115        depthFrameColor = cv2.applyColorMap(depthFrameColor, cv2.COLORMAP_HOT)
116
117        detections = inDet.detections
118
119        # If the frame is available, draw bounding boxes on it and show the frame
120        height = frame.shape[0]
121        width  = frame.shape[1]
122        for detection in detections:
123            roiData = detection.boundingBoxMapping
124            roi = roiData.roi
125            roi = roi.denormalize(depthFrameColor.shape[1], depthFrameColor.shape[0])
126            topLeft = roi.topLeft()
127            bottomRight = roi.bottomRight()
128            xmin = int(topLeft.x)
129            ymin = int(topLeft.y)
130            xmax = int(bottomRight.x)
131            ymax = int(bottomRight.y)
132            cv2.rectangle(depthFrameColor, (xmin, ymin), (xmax, ymax), color, cv2.FONT_HERSHEY_SCRIPT_SIMPLEX)
133
134            # Denormalize bounding box
135            x1 = int(detection.xmin * width)
136            x2 = int(detection.xmax * width)
137            y1 = int(detection.ymin * height)
138            y2 = int(detection.ymax * height)
139            try:
140                label = labelMap[detection.label]
141            except:
142                label = detection.label
143            cv2.putText(frame, str(label), (x1 + 10, y1 + 20), cv2.FONT_HERSHEY_TRIPLEX, 0.5, 255)
144            cv2.putText(frame, "{:.2f}".format(detection.confidence*100), (x1 + 10, y1 + 35), cv2.FONT_HERSHEY_TRIPLEX, 0.5, 255)
145            cv2.putText(frame, f"X: {int(detection.spatialCoordinates.x)} mm", (x1 + 10, y1 + 50), cv2.FONT_HERSHEY_TRIPLEX, 0.5, 255)
146            cv2.putText(frame, f"Y: {int(detection.spatialCoordinates.y)} mm", (x1 + 10, y1 + 65), cv2.FONT_HERSHEY_TRIPLEX, 0.5, 255)
147            cv2.putText(frame, f"Z: {int(detection.spatialCoordinates.z)} mm", (x1 + 10, y1 + 80), cv2.FONT_HERSHEY_TRIPLEX, 0.5, 255)
148
149            cv2.rectangle(frame, (x1, y1), (x2, y2), (255, 0, 0), cv2.FONT_HERSHEY_SIMPLEX)
150
151        cv2.imshow("depth", depthFrameColor)
152        cv2.imshow("preview", frame)
153
154        if cv2.waitKey(1) == ord('q'):
155            break

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