# Stereo Depth custom Mesh

This example shows how you can load custom mesh to the device and use it for depth calculation. In this example, mesh files are
generated from camera calibration data, but you can also use your own mesh files.

By default, [StereoDepth](https://docs.luxonis.com/software/depthai-components/nodes/stereo_depth.md) will use the same logic as
inside the def getMesh() to calculate mesh files whenever horizontal FOV is larger than 90°. You could also force calculate the
mesh using:

```python
stereo = pipeline.create(dai.node.StereoDepth)
# Enable mesh calculation to correct distortion:
stereo.enableDistortionCorrection(True)
```

StereoDepth node also allows you to load mesh files directly from a file path:

```python
stereo = pipeline.create(dai.node.StereoDepth)
stereo.loadMeshFiles('path/to/left_mesh', 'path/to/right_mesh')
```

## Demo

On the image above you can see that the rectified frame isn't as wide FOV as the original one, that's because the distortion
correction is applied (in this case via custom mesh files), so the disparity matching can be performed correctly.

## Setup

Please run the [install script](https://github.com/luxonis/depthai-python/blob/main/examples/install_requirements.py) to download
all required dependencies. Please note that this script must be ran from git context, so you have to download the
[depthai-python](https://github.com/luxonis/depthai-python) repository first and then run the script

```bash
git clone https://github.com/luxonis/depthai-python.git
cd depthai-python/examples
python3 install_requirements.py
```

For additional information, please follow the [installation guide](https://docs.luxonis.com/software/depthai/manual-install.md).

## Source code

#### Python

```python
#!/usr/bin/env python3

import cv2
import numpy as np
import depthai as dai
import argparse

parser = argparse.ArgumentParser()
parser.add_argument("-res", "--resolution", type=str, default="720",
    help="Sets the resolution on mono cameras. Options: 800 | 720 | 400")
parser.add_argument("-md", "--mesh_dir", type=str, default=None,
    help="Output directory for mesh files. If not specified mesh files won't be saved")
parser.add_argument("-lm", "--load_mesh", default=False, action="store_true",
    help="Read camera intrinsics, generate mesh files and load them into the stereo node.")
args = parser.parse_args()

meshDirectory = args.mesh_dir  # Output dir for mesh files
generateMesh = args.load_mesh  # Load mesh files
RES_MAP = {
    '800': {'w': 1280, 'h': 800, 'res': dai.MonoCameraProperties.SensorResolution.THE_800_P },
    '720': {'w': 1280, 'h': 720, 'res': dai.MonoCameraProperties.SensorResolution.THE_720_P },
    '400': {'w': 640, 'h': 400, 'res': dai.MonoCameraProperties.SensorResolution.THE_400_P }
}
if args.resolution not in RES_MAP:
    exit("Unsupported resolution!")

resolution = RES_MAP[args.resolution]

def getMesh(calibData):
    M1 = np.array(calibData.getCameraIntrinsics(dai.CameraBoardSocket.CAM_B, resolution['w'], resolution['h']))
    d1 = np.array(calibData.getDistortionCoefficients(dai.CameraBoardSocket.CAM_B))
    R1 = np.array(calibData.getStereoLeftRectificationRotation())
    M2 = np.array(calibData.getCameraIntrinsics(dai.CameraBoardSocket.CAM_C, resolution['w'], resolution['h']))
    d2 = np.array(calibData.getDistortionCoefficients(dai.CameraBoardSocket.CAM_C))
    R2 = np.array(calibData.getStereoRightRectificationRotation())
    mapXL, mapYL = cv2.initUndistortRectifyMap(M1, d1, R1, M2, (resolution['w'], resolution['h']), cv2.CV_32FC1)
    mapXR, mapYR = cv2.initUndistortRectifyMap(M2, d2, R2, M2, (resolution['w'], resolution['h']), cv2.CV_32FC1)

    meshCellSize = 16
    meshLeft = []
    meshRight = []

    for y in range(mapXL.shape[0] + 1):
        if y % meshCellSize == 0:
            rowLeft = []
            rowRight = []
            for x in range(mapXL.shape[1] + 1):
                if x % meshCellSize == 0:
                    if y == mapXL.shape[0] and x == mapXL.shape[1]:
                        rowLeft.append(mapYL[y - 1, x - 1])
                        rowLeft.append(mapXL[y - 1, x - 1])
                        rowRight.append(mapYR[y - 1, x - 1])
                        rowRight.append(mapXR[y - 1, x - 1])
                    elif y == mapXL.shape[0]:
                        rowLeft.append(mapYL[y - 1, x])
                        rowLeft.append(mapXL[y - 1, x])
                        rowRight.append(mapYR[y - 1, x])
                        rowRight.append(mapXR[y - 1, x])
                    elif x == mapXL.shape[1]:
                        rowLeft.append(mapYL[y, x - 1])
                        rowLeft.append(mapXL[y, x - 1])
                        rowRight.append(mapYR[y, x - 1])
                        rowRight.append(mapXR[y, x - 1])
                    else:
                        rowLeft.append(mapYL[y, x])
                        rowLeft.append(mapXL[y, x])
                        rowRight.append(mapYR[y, x])
                        rowRight.append(mapXR[y, x])
            if (mapXL.shape[1] % meshCellSize) % 2 != 0:
                rowLeft.append(0)
                rowLeft.append(0)
                rowRight.append(0)
                rowRight.append(0)

            meshLeft.append(rowLeft)
            meshRight.append(rowRight)

    meshLeft = np.array(meshLeft)
    meshRight = np.array(meshRight)

    return meshLeft, meshRight

def saveMeshFiles(meshLeft, meshRight, outputPath):
    print("Saving mesh to:", outputPath)
    meshLeft.tofile(outputPath + "/left_mesh.calib")
    meshRight.tofile(outputPath + "/right_mesh.calib")

def create_pipeline(device: dai.Device) -> dai.Pipeline:
    calibData = device.readCalibration()
    print("Creating Stereo Depth pipeline")
    pipeline = dai.Pipeline()

    camLeft = pipeline.create(dai.node.MonoCamera)
    camLeft.setBoardSocket(dai.CameraBoardSocket.LEFT)

    camRight = pipeline.create(dai.node.MonoCamera)
    camRight.setBoardSocket(dai.CameraBoardSocket.RIGHT)

    xoutRight = pipeline.create(dai.node.XLinkOut)
    xoutRight.setStreamName("right")
    camRight.out.link(xoutRight.input)

    for monoCam in (camLeft, camRight):  # Common config
        monoCam.setResolution(resolution['res'])
        # monoCam.setFps(20.0)

    stereo = pipeline.create(dai.node.StereoDepth)
    camLeft.out.link(stereo.left)
    camRight.out.link(stereo.right)
    stereo.setDefaultProfilePreset(dai.node.StereoDepth.PresetMode.HIGH_DENSITY)
    stereo.setRectifyEdgeFillColor(0)  # Black, to better see the cutout
    stereo.setLeftRightCheck(True)
    stereo.setExtendedDisparity(True)

    

    xoutDisparity = pipeline.create(dai.node.XLinkOut)
    xoutDisparity.setStreamName("disparity")
    stereo.disparity.link(xoutDisparity.input)

    xoutRectifRight = pipeline.create(dai.node.XLinkOut)
    xoutRectifRight.setStreamName("rectifiedRight")
    stereo.rectifiedRight.link(xoutRectifRight.input)

    # Create custom meshes from calibration data. Here you could also
    # load your own mesh files, or generate them in any other way.
    leftMesh, rightMesh = getMesh(calibData)
    if generateMesh:
        meshLeft = list(leftMesh.tobytes())
        meshRight = list(rightMesh.tobytes())
        # Load mesh data to the StereoDepth node
        stereo.loadMeshData(meshLeft, meshRight)

    if meshDirectory is not None:
        saveMeshFiles(leftMesh, rightMesh, meshDirectory)
    return pipeline

with dai.Device() as device:
    device.startPipeline(create_pipeline(device))

    # Create a receive queue for each stream
    qList = [device.getOutputQueue(stream, 8, blocking=False) for stream in ['right', 'rectifiedRight', 'disparity']]

    while True:
        for q in qList:
            name = q.getName()
            frame = q.get().getCvFrame()
            cv2.imshow(name, frame)
        if cv2.waitKey(1) == ord("q"):
            break
```

## Pipeline

### examples/stereo_depth_custom_mesh.pipeline.json

```json
{
  "pipeline": {
    "connections": [
      {
        "node1Id": 1,
        "node1Output": "out",
        "node1OutputGroup": "",
        "node2Id": 2,
        "node2Input": "in",
        "node2InputGroup": ""
      },
      {
        "node1Id": 0,
        "node1Output": "out",
        "node1OutputGroup": "",
        "node2Id": 3,
        "node2Input": "left",
        "node2InputGroup": ""
      },
      {
        "node1Id": 1,
        "node1Output": "out",
        "node1OutputGroup": "",
        "node2Id": 3,
        "node2Input": "right",
        "node2InputGroup": ""
      },
      {
        "node1Id": 3,
        "node1Output": "disparity",
        "node1OutputGroup": "",
        "node2Id": 4,
        "node2Input": "in",
        "node2InputGroup": ""
      },
      {
        "node1Id": 3,
        "node1Output": "rectifiedRight",
        "node1OutputGroup": "",
        "node2Id": 5,
        "node2Input": "in",
        "node2InputGroup": ""
      }
    ],
    "globalProperties": {
      "calibData": null,
      "cameraTuningBlobSize": null,
      "cameraTuningBlobUri": "",
      "leonCssFrequencyHz": 700000000.0,
      "leonMssFrequencyHz": 700000000.0,
      "pipelineName": null,
      "pipelineVersion": null,
      "sippBufferSize": 18432,
      "sippDmaBufferSize": 16384,
      "xlinkChunkSize": -1
    },
    "nodes": [
      [
        0,
        {
          "id": 0,
          "ioInfo": [
            [
              [
                "",
                "inputControl"
              ],
              {
                "blocking": true,
                "group": "",
                "id": 1,
                "name": "inputControl",
                "queueSize": 8,
                "type": 3,
                "waitForMessage": false
              }
            ],
            [
              [
                "",
                "out"
              ],
              {
                "blocking": false,
                "group": "",
                "id": 2,
                "name": "out",
                "queueSize": 8,
                "type": 0,
                "waitForMessage": false
              }
            ],
            [
              [
                "",
                "raw"
              ],
              {
                "blocking": false,
                "group": "",
                "id": 3,
                "name": "raw",
                "queueSize": 8,
                "type": 0,
                "waitForMessage": false
              }
            ],
            [
              [
                "",
                "frameEvent"
              ],
              {
                "blocking": false,
                "group": "",
                "id": 4,
                "name": "frameEvent",
                "queueSize": 8,
                "type": 0,
                "waitForMessage": false
              }
            ]
          ],
          "name": "MonoCamera",
          "properties": {
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            "cameraName": "",
            "fps": 30.0,
            "imageOrientation": -1,
            "initialControl": {
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              "aeMaxExposureTimeUs": 0,
              "aeRegion": {
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                "width": 0,
                "x": 0,
                "y": 0
              },
              "afRegion": {
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                "priority": 0,
                "width": 0,
                "x": 0,
                "y": 0
              },
              "antiBandingMode": 0,
              "autoFocusMode": 3,
              "awbLockMode": false,
              "awbMode": 0,
              "brightness": 0,
              "captureIntent": 0,
              "chromaDenoise": 0,
              "cmdMask": 0,
              "contrast": 0,
              "controlMode": 0,
              "effectMode": 0,
              "expCompensation": 0,
              "expManual": {
                "exposureTimeUs": 0,
                "frameDurationUs": 0,
                "sensitivityIso": 0
              },
              "frameSyncMode": 0,
              "lensPosAutoInfinity": 0,
              "lensPosAutoMacro": 0,
              "lensPosition": 0,
              "lensPositionRaw": 0.0,
              "lowPowerNumFramesBurst": 0,
              "lowPowerNumFramesDiscard": 0,
              "lumaDenoise": 0,
              "saturation": 0,
              "sceneMode": 0,
              "sharpness": 0,
              "strobeConfig": {
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                "enable": 0,
                "gpioNumber": 0
              },
              "strobeTimings": {
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                "exposureEndOffsetUs": 0
              },
              "wbColorTemp": 0
            },
            "isp3aFps": 0,
            "numFramesPool": 3,
            "numFramesPoolRaw": 3,
            "rawPacked": null,
            "resolution": 0
          }
        }
      ],
      [
        1,
        {
          "id": 1,
          "ioInfo": [
            [
              [
                "",
                "inputControl"
              ],
              {
                "blocking": true,
                "group": "",
                "id": 5,
                "name": "inputControl",
                "queueSize": 8,
                "type": 3,
                "waitForMessage": false
              }
            ],
            [
              [
                "",
                "out"
              ],
              {
                "blocking": false,
                "group": "",
                "id": 6,
                "name": "out",
                "queueSize": 8,
                "type": 0,
                "waitForMessage": false
              }
            ],
            [
              [
                "",
                "raw"
              ],
              {
                "blocking": false,
                "group": "",
                "id": 7,
                "name": "raw",
                "queueSize": 8,
                "type": 0,
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              }
            ],
            [
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              ],
              {
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                "group": "",
                "id": 8,
                "name": "frameEvent",
                "queueSize": 8,
                "type": 0,
                "waitForMessage": false
              }
            ]
          ],
          "name": "MonoCamera",
          "properties": {
            "boardSocket": 2,
            "cameraName": "",
            "fps": 30.0,
            "imageOrientation": -1,
            "initialControl": {
              "aeLockMode": false,
              "aeMaxExposureTimeUs": 0,
              "aeRegion": {
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                "width": 0,
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              },
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                "priority": 0,
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              },
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              "autoFocusMode": 3,
              "awbLockMode": false,
              "awbMode": 0,
              "brightness": 0,
              "captureIntent": 0,
              "chromaDenoise": 0,
              "cmdMask": 0,
              "contrast": 0,
              "controlMode": 0,
              "effectMode": 0,
              "expCompensation": 0,
              "expManual": {
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                "frameDurationUs": 0,
                "sensitivityIso": 0
              },
              "frameSyncMode": 0,
              "lensPosAutoInfinity": 0,
              "lensPosAutoMacro": 0,
              "lensPosition": 0,
              "lensPositionRaw": 0.0,
              "lowPowerNumFramesBurst": 0,
              "lowPowerNumFramesDiscard": 0,
              "lumaDenoise": 0,
              "saturation": 0,
              "sceneMode": 0,
              "sharpness": 0,
              "strobeConfig": {
                "activeLevel": 0,
                "enable": 0,
                "gpioNumber": 0
              },
              "strobeTimings": {
                "durationUs": 0,
                "exposureBeginOffsetUs": 0,
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              },
              "wbColorTemp": 0
            },
            "isp3aFps": 0,
            "numFramesPool": 3,
            "numFramesPoolRaw": 3,
            "rawPacked": null,
            "resolution": 0
          }
        }
      ],
      [
        2,
        {
          "id": 2,
          "ioInfo": [
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              ],
              {
                "blocking": true,
                "group": "",
                "id": 9,
                "name": "in",
                "queueSize": 8,
                "type": 3,
                "waitForMessage": true
              }
            ]
          ],
          "name": "XLinkOut",
          "properties": {
            "maxFpsLimit": -1.0,
            "metadataOnly": false,
            "streamName": "right"
          }
        }
      ],
      [
        3,
        {
          "id": 3,
          "ioInfo": [
            [
              [
                "",
                "inputConfig"
              ],
              {
                "blocking": false,
                "group": "",
                "id": 10,
                "name": "inputConfig",
                "queueSize": 4,
                "type": 3,
                "waitForMessage": false
              }
            ],
            [
              [
                "",
                "left"
              ],
              {
                "blocking": false,
                "group": "",
                "id": 11,
                "name": "left",
                "queueSize": 8,
                "type": 3,
                "waitForMessage": true
              }
            ],
            [
              [
                "",
                "debugExtDispLrCheckIt1"
              ],
              {
                "blocking": false,
                "group": "",
                "id": 23,
                "name": "debugExtDispLrCheckIt1",
                "queueSize": 8,
                "type": 0,
                "waitForMessage": false
              }
            ],
            [
              [
                "",
                "right"
              ],
              {
                "blocking": false,
                "group": "",
                "id": 12,
                "name": "right",
                "queueSize": 8,
                "type": 3,
                "waitForMessage": true
              }
            ],
            [
              [
                "",
                "syncedLeft"
              ],
              {
                "blocking": false,
                "group": "",
                "id": 13,
                "name": "syncedLeft",
                "queueSize": 8,
                "type": 0,
                "waitForMessage": false
              }
            ],
            [
              [
                "",
                "depth"
              ],
              {
                "blocking": false,
                "group": "",
                "id": 14,
                "name": "depth",
                "queueSize": 8,
                "type": 0,
                "waitForMessage": false
              }
            ],
            [
              [
                "",
                "disparity"
              ],
              {
                "blocking": false,
                "group": "",
                "id": 15,
                "name": "disparity",
                "queueSize": 8,
                "type": 0,
                "waitForMessage": false
              }
            ],
            [
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                "",
                "syncedRight"
              ],
              {
                "blocking": false,
                "group": "",
                "id": 16,
                "name": "syncedRight",
                "queueSize": 8,
                "type": 0,
                "waitForMessage": false
              }
            ],
            [
              [
                "",
                "debugDispCostDump"
              ],
              {
                "blocking": false,
                "group": "",
                "id": 21,
                "name": "debugDispCostDump",
                "queueSize": 8,
                "type": 0,
                "waitForMessage": false
              }
            ],
            [
              [
                "",
                "debugDispLrCheckIt2"
              ],
              {
                "blocking": false,
                "group": "",
                "id": 22,
                "name": "debugDispLrCheckIt2",
                "queueSize": 8,
                "type": 0,
                "waitForMessage": false
              }
            ],
            [
              [
                "",
                "rectifiedLeft"
              ],
              {
                "blocking": false,
                "group": "",
                "id": 17,
                "name": "rectifiedLeft",
                "queueSize": 8,
                "type": 0,
                "waitForMessage": false
              }
            ],
            [
              [
                "",
                "debugExtDispLrCheckIt2"
              ],
              {
                "blocking": false,
                "group": "",
                "id": 24,
                "name": "debugExtDispLrCheckIt2",
                "queueSize": 8,
                "type": 0,
                "waitForMessage": false
              }
            ],
            [
              [
                "",
                "rectifiedRight"
              ],
              {
                "blocking": false,
                "group": "",
                "id": 18,
                "name": "rectifiedRight",
                "queueSize": 8,
                "type": 0,
                "waitForMessage": false
              }
            ],
            [
              [
                "",
                "confidenceMap"
              ],
              {
                "blocking": false,
                "group": "",
                "id": 25,
                "name": "confidenceMap",
                "queueSize": 8,
                "type": 0,
                "waitForMessage": false
              }
            ],
            [
              [
                "",
                "outConfig"
              ],
              {
                "blocking": false,
                "group": "",
                "id": 19,
                "name": "outConfig",
                "queueSize": 8,
                "type": 0,
                "waitForMessage": false
              }
            ],
            [
              [
                "",
                "debugDispLrCheckIt1"
              ],
              {
                "blocking": false,
                "group": "",
                "id": 20,
                "name": "debugDispLrCheckIt1",
                "queueSize": 8,
                "type": 0,
                "waitForMessage": false
              }
            ]
          ],
          "name": "StereoDepth",
          "properties": {
            "alphaScaling": null,
            "baseline": null,
            "depthAlignCamera": -1,
            "depthAlignmentUseSpecTranslation": null,
            "disparityToDepthUseSpecTranslation": null,
            "enableRectification": true,
            "enableRuntimeStereoModeSwitch": false,
            "focalLength": null,
            "focalLengthFromCalibration": true,
            "height": null,
            "initialConfig": {
              "algorithmControl": {
                "centerAlignmentShiftFactor": null,
                "customDepthUnitMultiplier": 1000.0,
                "depthAlign": 0,
                "depthUnit": 2,
                "disparityShift": 0,
                "enableExtended": true,
                "enableLeftRightCheck": true,
                "enableSubpixel": false,
                "leftRightCheckThreshold": 10,
                "numInvalidateEdgePixels": 0,
                "subpixelFractionalBits": 3
              },
              "censusTransform": {
                "enableMeanMode": true,
                "kernelMask": 0,
                "kernelSize": -1,
                "threshold": 0
              },
              "costAggregation": {
                "divisionFactor": 1,
                "horizontalPenaltyCostP1": 250,
                "horizontalPenaltyCostP2": 500,
                "verticalPenaltyCostP1": 250,
                "verticalPenaltyCostP2": 500
              },
              "costMatching": {
                "confidenceThreshold": 245,
                "disparityWidth": 1,
                "enableCompanding": false,
                "invalidDisparityValue": 0,
                "linearEquationParameters": {
                  "alpha": 0,
                  "beta": 2,
                  "threshold": 127
                }
              },
              "postProcessing": {
                "bilateralSigmaValue": 0,
                "brightnessFilter": {
                  "maxBrightness": 256,
                  "minBrightness": 0
                },
                "decimationFilter": {
                  "decimationFactor": 1,
                  "decimationMode": 0
                },
                "median": 5,
                "spatialFilter": {
                  "alpha": 0.5,
                  "delta": 0,
                  "enable": false,
                  "holeFillingRadius": 2,
                  "numIterations": 1
                },
                "speckleFilter": {
                  "enable": false,
                  "speckleRange": 50
                },
                "temporalFilter": {
                  "alpha": 0.4000000059604645,
                  "delta": 0,
                  "enable": false,
                  "persistencyMode": 3
                },
                "thresholdFilter": {
                  "maxRange": 65535,
                  "minRange": 0
                }
              }
            },
            "mesh": {
              "meshLeftUri": "",
              "meshRightUri": "",
              "meshSize": null,
              "stepHeight": 16,
              "stepWidth": 16
            },
            "numFramesPool": 3,
            "numPostProcessingMemorySlices": -1,
            "numPostProcessingShaves": -1,
            "outHeight": null,
            "outKeepAspectRatio": true,
            "outWidth": null,
            "rectificationUseSpecTranslation": null,
            "rectifyEdgeFillColor": 0,
            "useHomographyRectification": null,
            "width": null
          }
        }
      ],
      [
        4,
        {
          "id": 4,
          "ioInfo": [
            [
              [
                "",
                "in"
              ],
              {
                "blocking": true,
                "group": "",
                "id": 26,
                "name": "in",
                "queueSize": 8,
                "type": 3,
                "waitForMessage": true
              }
            ]
          ],
          "name": "XLinkOut",
          "properties": {
            "maxFpsLimit": -1.0,
            "metadataOnly": false,
            "streamName": "disparity"
          }
        }
      ],
      [
        5,
        {
          "id": 5,
          "ioInfo": [
            [
              [
                "",
                "in"
              ],
              {
                "blocking": true,
                "group": "",
                "id": 27,
                "name": "in",
                "queueSize": 8,
                "type": 3,
                "waitForMessage": true
              }
            ]
          ],
          "name": "XLinkOut",
          "properties": {
            "maxFpsLimit": -1.0,
            "metadataOnly": false,
            "streamName": "rectifiedRight"
          }
        }
      ]
    ]
  }
}
```

### Need assistance?

Head over to [Discussion Forum](https://discuss.luxonis.com/) for technical support or any other questions you might have.