# Spatial Calculator Multi-ROI

This example shows how one can use multiple ROIs with a single
[SpatialLocationCalculator](https://docs.luxonis.com/software/depthai/examples/spatial_location_calculator.md) node. A similar
logic could be used as a simple depth line scanning camera for mobile robots.

### Similar samples:

 * [Spatial location calculator](https://docs.luxonis.com/software/depthai/examples/spatial_location_calculator.md)

## Demo

## 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 depthai as dai
import math
import numpy as np

# Create pipeline
pipeline = dai.Pipeline()

# Define sources and outputs
monoLeft = pipeline.create(dai.node.MonoCamera)
monoRight = pipeline.create(dai.node.MonoCamera)
stereo = pipeline.create(dai.node.StereoDepth)
spatialLocationCalculator = pipeline.create(dai.node.SpatialLocationCalculator)

xoutDepth = pipeline.create(dai.node.XLinkOut)
xoutSpatialData = pipeline.create(dai.node.XLinkOut)
xinSpatialCalcConfig = pipeline.create(dai.node.XLinkIn)

xoutDepth.setStreamName("depth")
xoutSpatialData.setStreamName("spatialData")
xinSpatialCalcConfig.setStreamName("spatialCalcConfig")

# Properties
monoLeft.setResolution(dai.MonoCameraProperties.SensorResolution.THE_400_P)
monoLeft.setCamera("left")
monoRight.setResolution(dai.MonoCameraProperties.SensorResolution.THE_400_P)
monoRight.setCamera("right")

stereo.setDefaultProfilePreset(dai.node.StereoDepth.PresetMode.HIGH_DENSITY)
stereo.setLeftRightCheck(True)
stereo.setSubpixel(True)
spatialLocationCalculator.inputConfig.setWaitForMessage(False)

# Create 10 ROIs
for i in range(10):
    config = dai.SpatialLocationCalculatorConfigData()
    config.depthThresholds.lowerThreshold = 200
    config.depthThresholds.upperThreshold = 10000
    config.roi = dai.Rect(dai.Point2f(i*0.1, 0.45), dai.Point2f((i+1)*0.1, 0.55))
    spatialLocationCalculator.initialConfig.addROI(config)

# Linking
monoLeft.out.link(stereo.left)
monoRight.out.link(stereo.right)

spatialLocationCalculator.passthroughDepth.link(xoutDepth.input)
stereo.depth.link(spatialLocationCalculator.inputDepth)

spatialLocationCalculator.out.link(xoutSpatialData.input)
xinSpatialCalcConfig.out.link(spatialLocationCalculator.inputConfig)

# Connect to device and start pipeline
with dai.Device(pipeline) as device:
    device.setIrLaserDotProjectorBrightness(1000)

    # 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)
    color = (0,200,40)
    fontType = cv2.FONT_HERSHEY_TRIPLEX

    while True:
        inDepth = depthQueue.get() # Blocking call, will wait until a new data has arrived

        depthFrame = inDepth.getFrame() # depthFrame values are in millimeters

        depth_downscaled = depthFrame[::4]
        if np.all(depth_downscaled == 0):
            min_depth = 0  # Set a default minimum depth value when all elements are zero
        else:
            min_depth = np.percentile(depth_downscaled[depth_downscaled != 0], 1)
        max_depth = np.percentile(depth_downscaled, 99)
        depthFrameColor = np.interp(depthFrame, (min_depth, max_depth), (0, 255)).astype(np.uint8)
        depthFrameColor = cv2.applyColorMap(depthFrameColor, cv2.COLORMAP_HOT)

        spatialData = spatialCalcQueue.get().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)

            coords = depthData.spatialCoordinates
            distance = math.sqrt(coords.x ** 2 + coords.y ** 2 + coords.z ** 2)

            cv2.rectangle(depthFrameColor, (xmin, ymin), (xmax, ymax), color, thickness=2)
            cv2.putText(depthFrameColor, "{:.1f}m".format(distance/1000), (xmin + 10, ymin + 20), fontType, 0.6, color)
        # Show the frame
        cv2.imshow("depth", depthFrameColor)

        if cv2.waitKey(1) == ord('q'):
            break
```

#### C++

```cpp
#include <iostream>

#include "utility.hpp"

// Includes common necessary includes for development using depthai library
#include "depthai/depthai.hpp"

static constexpr float stepSize = 0.05f;

static std::atomic<bool> newConfig{false};

int main() {
    using namespace std;

    // Create pipeline
    dai::Pipeline pipeline;

    // Define sources and outputs
    auto monoLeft = pipeline.create<dai::node::MonoCamera>();
    auto monoRight = pipeline.create<dai::node::MonoCamera>();
    auto stereo = pipeline.create<dai::node::StereoDepth>();
    auto spatialLocationCalculator = pipeline.create<dai::node::SpatialLocationCalculator>();

    auto xoutDepth = pipeline.create<dai::node::XLinkOut>();
    auto xoutSpatialData = pipeline.create<dai::node::XLinkOut>();
    auto xinSpatialCalcConfig = pipeline.create<dai::node::XLinkIn>();

    xoutDepth->setStreamName("depth");
    xoutSpatialData->setStreamName("spatialData");
    xinSpatialCalcConfig->setStreamName("spatialCalcConfig");

    // Properties
    monoLeft->setResolution(dai::MonoCameraProperties::SensorResolution::THE_400_P);
    monoLeft->setCamera("left");
    monoRight->setResolution(dai::MonoCameraProperties::SensorResolution::THE_400_P);
    monoRight->setCamera("right");

    stereo->setDefaultProfilePreset(dai::node::StereoDepth::PresetMode::HIGH_DENSITY);
    stereo->setLeftRightCheck(true);
    stereo->setExtendedDisparity(true);
    spatialLocationCalculator->inputConfig.setWaitForMessage(false);

    // Create 10 ROIs
    for(int i = 0; i < 10; i++) {
        dai::SpatialLocationCalculatorConfigData config;
        config.depthThresholds.lowerThreshold = 200;
        config.depthThresholds.upperThreshold = 10000;
        config.roi = dai::Rect(dai::Point2f(i * 0.1, 0.45), dai::Point2f((i + 1) * 0.1, 0.55));
        spatialLocationCalculator->initialConfig.addROI(config);
    }

    // Linking
    monoLeft->out.link(stereo->left);
    monoRight->out.link(stereo->right);

    spatialLocationCalculator->passthroughDepth.link(xoutDepth->input);
    stereo->depth.link(spatialLocationCalculator->inputDepth);

    spatialLocationCalculator->out.link(xoutSpatialData->input);
    xinSpatialCalcConfig->out.link(spatialLocationCalculator->inputConfig);

    // Connect to device and start pipeline
    dai::Device device(pipeline);
    device.setIrLaserDotProjectorIntensity(0.7f);

    // Output queue will be used to get the depth frames from the outputs defined above
    auto depthQueue = device.getOutputQueue("depth", 4, false);
    auto spatialCalcQueue = device.getOutputQueue("spatialData", 4, false);
    auto color = cv::Scalar(0, 200, 40);
    auto fontType = cv::FONT_HERSHEY_TRIPLEX;

    while(true) {
        auto inDepth = depthQueue->get<dai::ImgFrame>();

        cv::Mat depthFrame = inDepth->getFrame();  // depthFrame values are in millimeters

        cv::Mat depthFrameColor;
        cv::normalize(depthFrame, depthFrameColor, 255, 0, cv::NORM_INF, CV_8UC1);
        cv::equalizeHist(depthFrameColor, depthFrameColor);
        cv::applyColorMap(depthFrameColor, depthFrameColor, cv::COLORMAP_HOT);

        auto spatialData = spatialCalcQueue->get<dai::SpatialLocationCalculatorData>()->getSpatialLocations();
        for(auto depthData : spatialData) {
            auto roi = depthData.config.roi;
            roi = roi.denormalize(depthFrameColor.cols, depthFrameColor.rows);

            auto xmin = static_cast<int>(roi.topLeft().x);
            auto ymin = static_cast<int>(roi.topLeft().y);
            auto xmax = static_cast<int>(roi.bottomRight().x);
            auto ymax = static_cast<int>(roi.bottomRight().y);

            auto coords = depthData.spatialCoordinates;
            auto distance = std::sqrt(coords.x * coords.x + coords.y * coords.y + coords.z * coords.z);

            cv::rectangle(depthFrameColor, cv::Rect(cv::Point(xmin, ymin), cv::Point(xmax, ymax)), color);
            std::stringstream depthDistance;
            depthDistance.precision(2);
            depthDistance << fixed << static_cast<float>(distance / 1000.0f) << "m";
            cv::putText(depthFrameColor, depthDistance.str(), cv::Point(xmin + 10, ymin + 20), fontType, 0.5, color);
        }
        // Show the frame
        cv::imshow("depth", depthFrameColor);

        if(cv::waitKey(1) == 'q') {
            break;
        }
    }
    return 0;
}
```

## Pipeline

### Need assistance?

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