# Stereo Depth

This example showcases [SteroDepth node](https://docs.luxonis.com/software-v3/depthai/depthai-components/nodes/stereo_depth.md)
running stereo disparity matching on-device from the stereo camera (left and right) streams.

 * lrcheck: used for better occlusion handling. For more information [click
   here](https://docs.luxonis.com/software-v3/depthai/depthai-components/nodes/stereo_depth.md)
 * extended: suitable for short range objects. For more information [click
   here](https://docs.luxonis.com/software-v3/depthai/depthai-components/nodes/stereo_depth.md)
 * subpixel: suitable for long range. For more information [click
   here](https://docs.luxonis.com/software-v3/depthai/depthai-components/nodes/stereo_depth.md)

## Demo

This example requires the DepthAI v3 API, see [installation instructions](https://docs.luxonis.com/software-v3/depthai.md).

## Pipeline

### examples/stereo.pipeline.json

```json
{"pipeline": {"connections": [{"node1Id": 2, "node1Output": "syncedRight", "node1OutputGroup": "", "node2Id": 7, "node2Input": "in", "node2InputGroup": ""}, {"node1Id": 2, "node1Output": "syncedLeft", "node1OutputGroup": "", "node2Id": 5, "node2Input": "in", "node2InputGroup": ""}, {"node1Id": 2, "node1Output": "disparity", "node1OutputGroup": "", "node2Id": 3, "node2Input": "in", "node2InputGroup": ""}, {"node1Id": 1, "node1Output": "0", "node1OutputGroup": "dynamicOutputs", "node2Id": 2, "node2Input": "right", "node2InputGroup": ""}, {"node1Id": 0, "node1Output": "0", "node1OutputGroup": "dynamicOutputs", "node2Id": 2, "node2Input": "left", "node2InputGroup": ""}], "globalProperties": {"calibData": null, "cameraTuningBlobSize": null, "cameraTuningBlobUri": "", "leonCssFrequencyHz": 700000000.0, "leonMssFrequencyHz": 700000000.0, "pipelineName": null, "pipelineVersion": null, "sippBufferSize": 18432, "sippDmaBufferSize": 16384, "xlinkChunkSize": -1}, "nodes": [[7, {"alias": "", "id": 7, "ioInfo": [[["", "in"], {"blocking": true, "group": "", "id": 27, "name": "in", "queueSize": 3, "type": 3, "waitForMessage": false}]], "logLevel": 3, "name": "XLinkOut", "parentId": -1, "properties": {"maxFpsLimit": -1.0, "metadataOnly": false, "streamName": "__x_2_syncedRight"}}], [5, {"alias": "", "id": 5, "ioInfo": [[["", "in"], {"blocking": true, "group": "", "id": 26, "name": "in", "queueSize": 3, "type": 3, "waitForMessage": false}]], "logLevel": 3, "name": "XLinkOut", "parentId": -1, "properties": {"maxFpsLimit": -1.0, "metadataOnly": false, "streamName": "__x_2_syncedLeft"}}], [3, {"alias": "", "id": 3, "ioInfo": [[["", "in"], {"blocking": true, "group": "", "id": 25, "name": "in", "queueSize": 3, "type": 3, "waitForMessage": false}]], "logLevel": 3, "name": "XLinkOut", "parentId": -1, "properties": {"maxFpsLimit": -1.0, "metadataOnly": false, "streamName": "__x_2_disparity"}}], [2, {"alias": "", "id": 2, "ioInfo": [[["", "confidenceMap"], {"blocking": false, "group": "", "id": 24, "name": "confidenceMap", "queueSize": 8, "type": 0, "waitForMessage": false}], [["", "debugDispCostDump"], {"blocking": false, "group": "", "id": 23, "name": "debugDispCostDump", "queueSize": 8, "type": 0, "waitForMessage": false}], [["", "debugExtDispLrCheckIt2"], {"blocking": false, "group": "", "id": 22, "name": "debugExtDispLrCheckIt2", "queueSize": 8, "type": 0, "waitForMessage": false}], [["", "debugDispLrCheckIt2"], {"blocking": false, "group": "", "id": 20, "name": "debugDispLrCheckIt2", "queueSize": 8, "type": 0, "waitForMessage": false}], [["", "debugExtDispLrCheckIt1"], {"blocking": false, "group": "", "id": 21, "name": "debugExtDispLrCheckIt1", "queueSize": 8, "type": 0, "waitForMessage": false}], [["", "debugDispLrCheckIt1"], {"blocking": false, "group": "", "id": 19, "name": "debugDispLrCheckIt1", "queueSize": 8, "type": 0, "waitForMessage": false}], [["", "outConfig"], {"blocking": false, "group": "", "id": 18, "name": "outConfig", "queueSize": 8, "type": 0, "waitForMessage": false}], [["", "rectifiedRight"], {"blocking": false, "group": "", "id": 17, "name": "rectifiedRight", "queueSize": 8, "type": 0, "waitForMessage": false}], [["", "rectifiedLeft"], {"blocking": false, "group": "", "id": 16, "name": "rectifiedLeft", "queueSize": 8, "type": 0, "waitForMessage": false}], [["", "depth"], {"blocking": false, "group": "", "id": 12, "name": "depth", "queueSize": 8, "type": 0, "waitForMessage": false}], [["", "right"], {"blocking": true, "group": "", "id": 11, "name": "right", "queueSize": 3, "type": 3, "waitForMessage": false}], [["", "left"], {"blocking": true, "group": "", "id": 10, "name": "left", "queueSize": 3, "type": 3, "waitForMessage": false}], [["", "syncedRight"], {"blocking": false, "group": "", "id": 15, "name": "syncedRight", "queueSize": 8, "type": 0, "waitForMessage": false}], [["", "syncedLeft"], {"blocking": false, "group": "", "id": 14, "name": "syncedLeft", "queueSize": 8, "type": 0, "waitForMessage": false}], [["", "inputAlignTo"], {"blocking": false, "group": "", "id": 9, "name": "inputAlignTo", "queueSize": 1, "type": 3, "waitForMessage": true}], [["", "disparity"], {"blocking": false, "group": "", "id": 13, "name": "disparity", "queueSize": 8, "type": 0, "waitForMessage": false}], [["", "inputConfig"], {"blocking": true, "group": "", "id": 8, "name": "inputConfig", "queueSize": 3, "type": 3, "waitForMessage": false}]], "logLevel": 3, "name": "StereoDepth", "parentId": -1, "properties": {"alphaScaling": null, "baseline": null, "depthAlignCamera": -1, "depthAlignmentUseSpecTranslation": null, "disparityToDepthUseSpecTranslation": null, "enableFrameSync": true, "enableRectification": true, "enableRuntimeStereoModeSwitch": false, "focalLength": null, "focalLengthFromCalibration": true, "height": null, "initialConfig": {"algorithmControl": {"centerAlignmentShiftFactor": null, "customDepthUnitMultiplier": 1000.0, "depthAlign": 1, "depthUnit": 2, "disparityShift": 0, "enableExtended": true, "enableLeftRightCheck": true, "enableSubpixel": true, "enableSwLeftRightCheck": false, "leftRightCheckThreshold": 10, "numInvalidateEdgePixels": 0, "subpixelFractionalBits": 5}, "censusTransform": {"enableMeanMode": true, "kernelMask": 0, "kernelSize": -1, "noiseThresholdOffset": 1, "noiseThresholdScale": 1, "threshold": 0}, "confidenceMetrics": {"flatnessConfidenceThreshold": 2, "flatnessConfidenceWeight": 8, "flatnessOverride": false, "motionVectorConfidenceThreshold": 1, "motionVectorConfidenceWeight": 4, "occlusionConfidenceWeight": 20}, "costAggregation": {"divisionFactor": 1, "horizontalPenaltyCostP1": 250, "horizontalPenaltyCostP2": 500, "p1Config": {"defaultValue": 11, "edgeThreshold": 15, "edgeValue": 10, "enableAdaptive": true, "smoothThreshold": 5, "smoothValue": 22}, "p2Config": {"defaultValue": 33, "edgeValue": 22, "enableAdaptive": true, "smoothValue": 63}, "verticalPenaltyCostP1": 250, "verticalPenaltyCostP2": 500}, "costMatching": {"confidenceThreshold": 55, "disparityWidth": 1, "enableCompanding": false, "enableSwConfidenceThresholding": false, "invalidDisparityValue": 0, "linearEquationParameters": {"alpha": 0, "beta": 2, "threshold": 127}}, "filtersBackend": 2, "postProcessing": {"adaptiveMedianFilter": {"confidenceThreshold": 200, "enable": true}, "bilateralSigmaValue": 0, "brightnessFilter": {"maxBrightness": 256, "minBrightness": 0}, "decimationFilter": {"decimationFactor": 1, "decimationMode": 0}, "filteringOrder": [3, 1, 2, 4, 5], "holeFilling": {"enable": true, "fillConfidenceThreshold": 200, "highConfidenceThreshold": 210, "invalidateDisparities": true, "minValidDisparity": 1}, "median": 0, "spatialFilter": {"alpha": 0.5, "delta": 0, "enable": false, "holeFillingRadius": 2, "numIterations": 1}, "speckleFilter": {"differenceThreshold": 2, "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}}], [1, {"alias": "", "id": 1, "ioInfo": [[["dynamicOutputs", "0"], {"blocking": false, "group": "dynamicOutputs", "id": 7, "name": "0", "queueSize": 8, "type": 0, "waitForMessage": false}], [["", "raw"], {"blocking": false, "group": "", "id": 6, "name": "raw", "queueSize": 8, "type": 0, "waitForMessage": false}], [["", "mockIsp"], {"blocking": true, "group": "", "id": 5, "name": "mockIsp", "queueSize": 8, "type": 3, "waitForMessage": false}], [["", "inputControl"], {"blocking": true, "group": "", "id": 4, "name": "inputControl", "queueSize": 3, "type": 3, "waitForMessage": false}]], "logLevel": 3, "name": "Camera", "parentId": -1, "properties": {"boardSocket": 2, "cameraName": "", "fps": -1.0, "imageOrientation": -1, "initialControl": {"aeLockMode": false, "aeMaxExposureTimeUs": 6, "aeRegion": {"height": 0, "priority": 598981968, "width": 0, "x": 97, "y": 0}, "afRegion": {"height": 9139, "priority": 24438, "width": 47888, "x": 24438, "y": 0}, "antiBandingMode": 179, "autoFocusMode": 3, "awbLockMode": false, "awbMode": 96, "brightness": 0, "captureIntent": 35, "chromaDenoise": 104, "cmdMask": 0, "contrast": 104, "controlMode": 118, "effectMode": 95, "enableHdr": false, "expCompensation": 0, "expManual": {"exposureTimeUs": 0, "frameDurationUs": 0, "sensitivityIso": 400}, "frameSyncMode": 0, "lensPosAutoInfinity": 0, "lensPosAutoMacro": 0, "lensPosition": 0, "lensPositionRaw": 0.0, "lowPowerNumFramesBurst": 240, "lowPowerNumFramesDiscard": 182, "lumaDenoise": 103, "miscControls": [], "saturation": 101, "sceneMode": 189, "sharpness": 105, "strobeConfig": {"activeLevel": 224, "enable": 0, "gpioNumber": -69}, "strobeTimings": {"durationUs": 24438, "exposureBeginOffsetUs": 24438, "exposureEndOffsetUs": 598981744}, "wbColorTemp": 0}, "isp3aFps": 0, "mockIspHeight": -1, "mockIspWidth": -1, "numFramesPoolIsp": 3, "numFramesPoolPreview": 4, "numFramesPoolRaw": 3, "numFramesPoolStill": 4, "numFramesPoolVideo": 4, "outputRequests": [{"enableUndistortion": null, "fps": {"value": null}, "resizeMode": 0, "size": {"value": {"index": 0, "value": [1280, 800]}}, "type": 22}], "resolutionHeight": -1, "resolutionWidth": -1}}], [0, {"alias": "", "id": 0, "ioInfo": [[["dynamicOutputs", "0"], {"blocking": false, "group": "dynamicOutputs", "id": 3, "name": "0", "queueSize": 8, "type": 0, "waitForMessage": false}], [["", "raw"], {"blocking": false, "group": "", "id": 2, "name": "raw", "queueSize": 8, "type": 0, "waitForMessage": false}], [["", "mockIsp"], {"blocking": true, "group": "", "id": 1, "name": "mockIsp", "queueSize": 8, "type": 3, "waitForMessage": false}], [["", "inputControl"], {"blocking": true, "group": "", "id": 0, "name": "inputControl", "queueSize": 3, "type": 3, "waitForMessage": false}]], "logLevel": 3, "name": "Camera", "parentId": -1, "properties": {"boardSocket": 1, "cameraName": "", "fps": -1.0, "imageOrientation": -1, "initialControl": {"aeLockMode": false, "aeMaxExposureTimeUs": 100663297, "aeRegion": {"height": 0, "priority": 599053840, "width": 0, "x": 4163, "y": 1}, "afRegion": {"height": 0, "priority": 0, "width": 0, "x": 24438, "y": 0}, "antiBandingMode": 180, "autoFocusMode": 3, "awbLockMode": false, "awbMode": 88, "brightness": -123, "captureIntent": 35, "chromaDenoise": 0, "cmdMask": 0, "contrast": -83, "controlMode": 118, "effectMode": 95, "enableHdr": false, "expCompensation": 45, "expManual": {"exposureTimeUs": 24438, "frameDurationUs": 24438, "sensitivityIso": 599053948}, "frameSyncMode": 0, "lensPosAutoInfinity": 144, "lensPosAutoMacro": 214, "lensPosition": 0, "lensPositionRaw": 0.0, "lowPowerNumFramesBurst": 0, "lowPowerNumFramesDiscard": 0, "lumaDenoise": 0, "miscControls": [], "saturation": 18, "sceneMode": 214, "sharpness": 0, "strobeConfig": {"activeLevel": 184, "enable": 0, "gpioNumber": -36}, "strobeTimings": {"durationUs": 12, "exposureBeginOffsetUs": 24438, "exposureEndOffsetUs": 17}, "wbColorTemp": 0}, "isp3aFps": 0, "mockIspHeight": -1, "mockIspWidth": -1, "numFramesPoolIsp": 3, "numFramesPoolPreview": 4, "numFramesPoolRaw": 3, "numFramesPoolStill": 4, "numFramesPoolVideo": 4, "outputRequests": [{"enableUndistortion": null, "fps": {"value": null}, "resizeMode": 0, "size": {"value": {"index": 0, "value": [1280, 800]}}, "type": 22}], "resolutionHeight": -1, "resolutionWidth": -1}}]]}}
```

## Source code

#### Python

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

import cv2
import depthai as dai
import numpy as np

pipeline = dai.Pipeline()
monoLeft = pipeline.create(dai.node.Camera).build(dai.CameraBoardSocket.CAM_B)
monoRight = pipeline.create(dai.node.Camera).build(dai.CameraBoardSocket.CAM_C)
stereo = pipeline.create(dai.node.StereoDepth)

# Linking
monoLeftOut = monoLeft.requestFullResolutionOutput()
monoRightOut = monoRight.requestFullResolutionOutput()
monoLeftOut.link(stereo.left)
monoRightOut.link(stereo.right)

stereo.setRectification(True)
stereo.setExtendedDisparity(True)
stereo.setLeftRightCheck(True)

disparityQueue = stereo.disparity.createOutputQueue()

colorMap = cv2.applyColorMap(np.arange(256, dtype=np.uint8), cv2.COLORMAP_JET)
colorMap[0] = [0, 0, 0]  # to make zero-disparity pixels black

with pipeline:
    pipeline.start()
    maxDisparity = 1
    while pipeline.isRunning():
        disparity = disparityQueue.get()
        assert isinstance(disparity, dai.ImgFrame)
        npDisparity = disparity.getFrame()
        maxDisparity = max(maxDisparity, np.max(npDisparity))
        colorizedDisparity = cv2.applyColorMap(((npDisparity / maxDisparity) * 255).astype(np.uint8), colorMap)
        cv2.imshow("disparity", colorizedDisparity)
        key = cv2.waitKey(1)
        if key == ord('q'):
            pipeline.stop()
            break
```

#### C++

```cpp
#include <atomic>
#include <csignal>
#include <opencv2/opencv.hpp>

#include "depthai/depthai.hpp"

std::atomic<bool> quitEvent(false);

void signalHandler(int) {
    quitEvent = true;
}

int main() {
    signal(SIGTERM, signalHandler);
    signal(SIGINT, signalHandler);

    dai::Pipeline pipeline;

    auto monoLeft = pipeline.create<dai::node::Camera>()->build(dai::CameraBoardSocket::CAM_B);
    auto monoRight = pipeline.create<dai::node::Camera>()->build(dai::CameraBoardSocket::CAM_C);

    auto stereo = pipeline.create<dai::node::StereoDepth>();

    auto monoLeftOut = monoLeft->requestFullResolutionOutput();
    auto monoRightOut = monoRight->requestFullResolutionOutput();

    monoLeftOut->link(stereo->left);
    monoRightOut->link(stereo->right);

    stereo->setRectification(true);
    stereo->setExtendedDisparity(true);
    stereo->setLeftRightCheck(true);

    auto disparityQueue = stereo->disparity.createOutputQueue();

    double maxDisparity = 1.0;
    pipeline.start();
    while(pipeline.isRunning() && !quitEvent) {
        auto disparity = disparityQueue->get<dai::ImgFrame>();
        cv::Mat npDisparity = disparity->getFrame();

        double minVal, curMax;
        cv::minMaxLoc(npDisparity, &minVal, &curMax);
        maxDisparity = std::max(maxDisparity, curMax);

        // Normalize the disparity image to an 8-bit scale.
        cv::Mat normalized;
        npDisparity.convertTo(normalized, CV_8UC1, 255.0 / maxDisparity);

        cv::Mat colorizedDisparity;
        cv::applyColorMap(normalized, colorizedDisparity, cv::COLORMAP_JET);

        // Set pixels with zero disparity to black.
        colorizedDisparity.setTo(cv::Scalar(0, 0, 0), normalized == 0);

        cv::imshow("disparity", colorizedDisparity);

        int key = cv::waitKey(1);
        if(key == 'q') {
            break;
        }
    }

    pipeline.stop();
    pipeline.wait();

    return 0;
}
```

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