> For the complete documentation index, see [llms.txt](https://docs.auterion.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.auterion.com/app-development/auterion-sdk/system-state-api-1.md).

# Camera API

{% hint style="info" %}
Related C++ Header in the Auterion SDK:`<auterion_sdk/camera/camera.hpp>`
{% endhint %}

Auterion SDK provides an interface for enumerating and subscribing to cameras and images.

In the simplest case (useful for testing), we can open the first found camera, and register a callback for image updates:

```cpp
std::optional<auterion::Camera> camera = auterion::Camera::openFirst(sdk);
if (camera) {
    printf("Got camera: %s, model=%s\n", camera->descriptor().unique_name.c_str(),
           camera->descriptor().camera_model.c_str());

    camera->subscribeImage([](const auterion::Image& image) {
        // The image data is available as image.data(),
        // encoded as image.header().encoding
        printf("Got image: size=%dx%d\n", image.width(), image.height());
    });
} else {
    printf("Timeout, no camera found\n");
}

```

As the set of available cameras depends on the system, each camera provides a descriptor, which can be used to select a camera based on its properties, such as the model name, mount orientation or purpose.

For example to select the camera used for surveys:

```cpp
std::optional<auterion::Camera> camera = auterion::Camera::open(
    sdk,
    [](const auterion::CameraDescriptor& descriptor) {
        // The camera will be selected for the first descriptor that returns true here
        return descriptor.primary_purpose ==
            auterion::CameraDescriptor::PrimaryPurpose::Survey;
    });
if (camera) {
    // ...
}
```

## Image Data

The raw image data can be accessed from the callback via `image.data()`.

The image can be converted to an OpenCV structure like this:

```cpp
const cv::Mat cv_mat = image.asOpenCVMat();
```

{% hint style="danger" %}
If you want to use the image outside of the callback, or make modifications, it is required to make a copy of the image data.
{% endhint %}

## CameraMonitor

In addition, there's also a `CameraMonitor` class that can be used to get notified when cameras are attached or removed from the system:

```cpp
auto monitor = auterion::CameraMonitor(
    sdk,
    [](const auterion::CameraDescriptor& descriptor) {
        printf("Camera found: %s\n", descriptor.camera_model.c_str());
    },
    [](const auterion::CameraDescriptor& descriptor) {
        printf("Camera removed: %s\n", descriptor.camera_model.c_str());
    });
```