Base Depth Estimation

# call base depth estimation to set base depth for height calculations
def baseDepthEstimation(pipeline, topLeft, bottomRight, config):
    st.warning('Please make sure the bounding box area is clear of objects.')
    col1, col2 = st.beta_columns(2)
    with col1:
        st.text('Preview window.')
    with col2:
        st.text('Click start to calibrate depth for avg. 25 frames')
        start = st.button('Start Calibration')

    # Pipeline is defined, now we can connect to the device
    with dai.Device(pipeline) as device:
        device.startPipeline()

        # Output queue will be used to get the depth frames from the outputs defined above
        depthQueue = device.getOutputQueue(name="depth", maxSize=4, blocking=False)
        spatialCalcQueue = device.getOutputQueue(name="spatialData", maxSize=4, blocking=False)
        spatialCalcConfigInQueue = device.getInputQueue("spatialCalcConfig")

        color = (255, 255, 255)
        noFrames = 0
        frameST = col1.empty()
        frameST2 = col2.empty()
        baseDepth = 0.0
        DepthValue = 0.0
        count = False
        fontType = cv2.FONT_HERSHEY_TRIPLEX

        while True:
            inDepth = depthQueue.get()  # Blocking call, will wait until a new data has arrived
            inDepthAvg = spatialCalcQueue.get()  # Blocking call, will wait until a new data has arrived
            preview = device.getOutputQueue('preview').get()

            img = preview.getFrame()

            depthFrame = inDepth.getFrame()
            depthFrameColor = cv2.normalize(depthFrame, None, 255, 0, cv2.NORM_INF, cv2.CV_8UC1)
            depthFrameColor = cv2.equalizeHist(depthFrameColor)
            depthFrameColor = cv2.applyColorMap(depthFrameColor, cv2.COLORMAP_JET)

            spatialData = inDepthAvg.getSpatialLocations()
            for depthData in spatialData:
                roi = depthData.config.roi
                roi = roi.denormalize(width=depthFrameColor.shape[ 1 ], height=depthFrameColor.shape[ 0 ])
                xmin = int(roi.topLeft().x)
                ymin = int(roi.topLeft().y)
                xmax = int(roi.bottomRight().x)
                ymax = int(roi.bottomRight().y)

                # preview window info
                cv2.rectangle(img, (xmin, ymin), (xmax, ymax), color, cv2.FONT_HERSHEY_SCRIPT_SIMPLEX)
                cv2.putText(img, f"X: {int(depthData.spatialCoordinates.x)} mm", (xmin + 10, ymin + 20),
                            fontType, 0.5, color)
                cv2.putText(img, f"Y: {int(depthData.spatialCoordinates.y)} mm", (xmin + 10, ymin + 35),
                            fontType, 0.5, color)
                cv2.putText(img, f"Z: {int(depthData.spatialCoordinates.z)} mm", (xmin + 10, ymin + 50),
                            fontType, 0.5, color)

                # depth window info
                cv2.rectangle(depthFrameColor, (xmin, ymin), (xmax, ymax), color, cv2.FONT_HERSHEY_SCRIPT_SIMPLEX)
                cv2.putText(depthFrameColor, f"X: {int(depthData.spatialCoordinates.x)} mm", (xmin + 10, ymin + 20),
                            fontType, 0.5, color)
                cv2.putText(depthFrameColor, f"Y: {int(depthData.spatialCoordinates.y)} mm", (xmin + 10, ymin + 35),
                            fontType, 0.5, color)
                cv2.putText(depthFrameColor, f"Z: {int(depthData.spatialCoordinates.z)} mm", (xmin + 10, ymin + 50),
                            fontType, 0.5, color)

                if start:
                    start = False
                    count = True
                    noFrames = 1

                if count:
                    DepthValue = (depthData.spatialCoordinates.z) / 10
                    baseDepth += DepthValue
                    print(baseDepth)
                    DepthValue = 0.0

                if noFrames == 25 and count == True:
                    # Base depth value calculation, dividing by no. of frames for the average
                    count = False
                    print('Frames count {:d}'.format(noFrames))
                    baseDepth = baseDepth / 25
                    print('base depth {:>2f}'.format(baseDepth))
                    st.text("Base Depth = {:>2f}".format(baseDepth))
                    cv2.destroyAllWindows()
                    return baseDepth

                with col1:
                    frameST.image(img, channels='BGR')
                with col2:
                    frameST2.image(depthFrameColor)

                noFrames += 1

                if cv2.waitKey(1) & 0xFF == ord('q'):
                    break