Feature Detector

1#!/usr/bin/env python3
2
3import cv2
4import depthai as dai
5
6
7# Create pipeline
8pipeline = dai.Pipeline()
9
10# Define sources and outputs
11monoLeft = pipeline.create(dai.node.MonoCamera)
12monoRight = pipeline.create(dai.node.MonoCamera)
13featureTrackerLeft = pipeline.create(dai.node.FeatureTracker)
14featureTrackerRight = pipeline.create(dai.node.FeatureTracker)
15
16xoutPassthroughFrameLeft = pipeline.create(dai.node.XLinkOut)
17xoutTrackedFeaturesLeft = pipeline.create(dai.node.XLinkOut)
18xoutPassthroughFrameRight = pipeline.create(dai.node.XLinkOut)
19xoutTrackedFeaturesRight = pipeline.create(dai.node.XLinkOut)
20xinTrackedFeaturesConfig = pipeline.create(dai.node.XLinkIn)
21
22xoutPassthroughFrameLeft.setStreamName("passthroughFrameLeft")
23xoutTrackedFeaturesLeft.setStreamName("trackedFeaturesLeft")
24xoutPassthroughFrameRight.setStreamName("passthroughFrameRight")
25xoutTrackedFeaturesRight.setStreamName("trackedFeaturesRight")
26xinTrackedFeaturesConfig.setStreamName("trackedFeaturesConfig")
27
28# Properties
29monoLeft.setResolution(dai.MonoCameraProperties.SensorResolution.THE_400_P)
30monoLeft.setCamera("left")
31monoRight.setResolution(dai.MonoCameraProperties.SensorResolution.THE_400_P)
32monoRight.setCamera("right")
33
34# Disable optical flow
35featureTrackerLeft.initialConfig.setMotionEstimator(False)
36featureTrackerRight.initialConfig.setMotionEstimator(False)
37
38# Linking
39monoLeft.out.link(featureTrackerLeft.inputImage)
40featureTrackerLeft.passthroughInputImage.link(xoutPassthroughFrameLeft.input)
41featureTrackerLeft.outputFeatures.link(xoutTrackedFeaturesLeft.input)
42xinTrackedFeaturesConfig.out.link(featureTrackerLeft.inputConfig)
43
44monoRight.out.link(featureTrackerRight.inputImage)
45featureTrackerRight.passthroughInputImage.link(xoutPassthroughFrameRight.input)
46featureTrackerRight.outputFeatures.link(xoutTrackedFeaturesRight.input)
47xinTrackedFeaturesConfig.out.link(featureTrackerRight.inputConfig)
48
49featureTrackerConfig = featureTrackerRight.initialConfig.get()
50
51print("Press 's' to switch between Harris and Shi-Thomasi corner detector!")
52
53# Connect to device and start pipeline
54with dai.Device(pipeline) as device:
55
56    # Output queues used to receive the results
57    passthroughImageLeftQueue = device.getOutputQueue("passthroughFrameLeft", 8, False)
58    outputFeaturesLeftQueue = device.getOutputQueue("trackedFeaturesLeft", 8, False)
59    passthroughImageRightQueue = device.getOutputQueue("passthroughFrameRight", 8, False)
60    outputFeaturesRightQueue = device.getOutputQueue("trackedFeaturesRight", 8, False)
61
62    inputFeatureTrackerConfigQueue = device.getInputQueue("trackedFeaturesConfig")
63
64    leftWindowName = "left"
65    rightWindowName = "right"
66
67    def drawFeatures(frame, features):
68        pointColor = (0, 0, 255)
69        circleRadius = 2
70        for feature in features:
71            cv2.circle(frame, (int(feature.position.x), int(feature.position.y)), circleRadius, pointColor, -1, cv2.LINE_AA, 0)
72
73    while True:
74        inPassthroughFrameLeft = passthroughImageLeftQueue.get()
75        passthroughFrameLeft = inPassthroughFrameLeft.getFrame()
76        leftFrame = cv2.cvtColor(passthroughFrameLeft, cv2.COLOR_GRAY2BGR)
77
78        inPassthroughFrameRight = passthroughImageRightQueue.get()
79        passthroughFrameRight = inPassthroughFrameRight.getFrame()
80        rightFrame = cv2.cvtColor(passthroughFrameRight, cv2.COLOR_GRAY2BGR)
81
82        trackedFeaturesLeft = outputFeaturesLeftQueue.get().trackedFeatures
83        drawFeatures(leftFrame, trackedFeaturesLeft)
84
85        trackedFeaturesRight = outputFeaturesRightQueue.get().trackedFeatures
86        drawFeatures(rightFrame, trackedFeaturesRight)
87
88        # Show the frame
89        cv2.imshow(leftWindowName, leftFrame)
90        cv2.imshow(rightWindowName, rightFrame)
91
92        key = cv2.waitKey(1)
93        if key == ord('q'):
94            break
95        elif key == ord('s'):
96            if featureTrackerConfig.cornerDetector.type == dai.FeatureTrackerConfig.CornerDetector.Type.HARRIS:
97                featureTrackerConfig.cornerDetector.type = dai.FeatureTrackerConfig.CornerDetector.Type.SHI_THOMASI
98                print("Switching to Shi-Thomasi")
99            else:
100                featureTrackerConfig.cornerDetector.type = dai.FeatureTrackerConfig.CornerDetector.Type.HARRIS
101                print("Switching to Harris")
102
103            cfg = dai.FeatureTrackerConfig()
104            cfg.set(featureTrackerConfig)
105            inputFeatureTrackerConfigQueue.send(cfg)