> For the complete documentation index, see [llms.txt](https://stage-precision.gitbook.io/grid/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://stage-precision.gitbook.io/grid/camera-calibration/project-setup/camera-image-input.md).

# Camera Image Input

All camera calibration workflows require a live image from the real camera.

In Grid Studio, this camera image is provided through a **Media Input** object. The Media Input receives the video signal and makes it available to the calibration tools as an **ImageProvider**.

{% hint style="info" %}
The camera image used for calibration should be the raw camera signal. Do not use an already undistorted, distorted, cropped, scaled, or composited image.
{% endhint %}

***

## Add a Media Input

Add a **Media Input** object to your project and select the camera source you want to use for calibration.

<div align="left"><figure><img src="/files/kz3VS7tbqM2y9iK1L7cO" alt="Adding Media IO, Setting it and checking image source toggle" width="563"><figcaption></figcaption></figure></div>

The Media Input should be enabled as an **ImageProvider**. This is enabled by default.

The ImageProvider allows the calibration tools to access the live camera image.

{% hint style="info" %}
If you do not see your video source, try setting the video feed to `1080p`.
{% endhint %}

***

## Check the Video Signal

Before starting a calibration workflow, make sure the video signal is visible and stable.

You can use the Media Input preview or the dedicated viewer window to check the signal before proceeding.

<div align="left"><figure><img src="/files/LfaPO8ilr7cCDfmaAAe9" alt="Gif of opening a viewer window and checking the media input" width="563"><figcaption></figcaption></figure></div>

### What to Check

Make sure that:

* the correct camera source is selected
* the image is visible
* the image is not frozen
* the image is not cropped or scaled unexpectedly
* the full camera frame is available
* the signal matches the camera view you want to calibrate

### Raw Camera Image

The calibration should use the original camera image.

This is important because Grid Studio calculates the lens distortion from the camera image. If the image has already been undistorted, distorted, cropped, or processed before it reaches Grid Studio, the calibration result may be incorrect.

Use the same camera signal that represents the real optical image from the lens.

***

## Select the Image Input in the Calibration Object

After creating the Media Input, select the **Calibration Object** used for your workflow.

In the Inspector, assign the Media Input as the image source for the calibration.

The calibration tool uses this image source for live preview, capture creation, pattern detection, and Manual Marker workflows.

***

## Image Resolution

Grid Studio reads the image resolution from the incoming video signal automatically.

You do not need to manually enter the image resolution for the Media Input.

However, the signal should still match the actual camera feed used for calibration. Avoid using a signal that is scaled, letterboxed, cropped, or converted by another system before it reaches Grid Studio.

***

## Select the Media Input for the Calibration Workflow

A project can contain multiple **Media Input** objects.

Each calibration workflow needs to know which Media Input should be used as the camera image source.

To assign the image source, select the **Calibration Object** and choose the correct Media Input in the Inspector.

The selected Media Input is then used by the calibration workflow to:

* access the live camera image
* create calibration captures
* detect Calibration Patterns
* reference Measurement Points in the Manual Marker Editor
* visually inspect the camera image during setup

{% hint style="info" %}
Make sure the selected Media Input belongs to the camera you want to calibrate. If multiple Media Inputs exist in the project, choosing the wrong one will use the wrong camera image for the calibration.
{% endhint %}

***

## Before Continuing Checklist

Before continuing with the calibration setup, check the following:

* A **Media Input** object has been added.
* The correct camera source is selected.
* The Media Input is enabled as an **ImageProvider**.
* The live image is visible in the preview or viewer window.
* The image is the raw camera signal.
* The image is not cropped, scaled, undistorted, distorted, or composited.
* The Media Input is assigned in the Calibration Object Inspector.