# cameraundistort

This element performs camera calibration.

Once the calibration procedure is done:

- An event, containing the camera correction parameters, is sent upstream and downstream to be consumed by cameraundistort elements.
- The settings property is set to the camera correction parameters (as an opaque string of serialized OpenCV objects). The value of this property can later be used to configure a cameraundistort element.
- The element becomes idle and can later be restarted [TODO].

Based on this tutorial: https://docs.opencv.org/2.4/doc/tutorials/calib3d/camera_calibration/camera_calibration.html

## Example pipelines

     gst-launch-1.0 -v v4l2src ! videoconvert ! cameraundistort ! cameracalibrate | autovideosink

will correct camera distortion once camera calibration is done.

## Hierarchy

    GObject
        ╰──GInitiallyUnowned
            ╰──GstObject
                ╰──GstElement
                    ╰──GstBaseTransform
                        ╰──GstVideoFilter
                            ╰──GstOpencvVideoFilter
                                ╰──cameraundistort

## Factory details

Authors: – Philippe Renon

Classification: – `Filter/Effect/Video`

Rank – none

Plugin – opencv

Package – GStreamer Bad Plug-ins

## Pad Templates

### `sink`

    video/x-raw:
             format: GRAY16_LE
              width: [ 1, 2147483647 ]
             height: [ 1, 2147483647 ]
          framerate: [ 0/1, 2147483647/1 ]
    video/x-raw:
             format: GRAY16_BE
              width: [ 1, 2147483647 ]
             height: [ 1, 2147483647 ]
          framerate: [ 0/1, 2147483647/1 ]
    video/x-raw:
             format: RGBx
              width: [ 1, 2147483647 ]
             height: [ 1, 2147483647 ]
          framerate: [ 0/1, 2147483647/1 ]
    video/x-raw:
             format: xRGB
              width: [ 1, 2147483647 ]
             height: [ 1, 2147483647 ]
          framerate: [ 0/1, 2147483647/1 ]
    video/x-raw:
             format: BGRx
              width: [ 1, 2147483647 ]
             height: [ 1, 2147483647 ]
          framerate: [ 0/1, 2147483647/1 ]
    video/x-raw:
             format: xBGR
              width: [ 1, 2147483647 ]
             height: [ 1, 2147483647 ]
          framerate: [ 0/1, 2147483647/1 ]
    video/x-raw:
             format: RGBA
              width: [ 1, 2147483647 ]
             height: [ 1, 2147483647 ]
          framerate: [ 0/1, 2147483647/1 ]
    video/x-raw:
             format: ARGB
              width: [ 1, 2147483647 ]
             height: [ 1, 2147483647 ]
          framerate: [ 0/1, 2147483647/1 ]
    video/x-raw:
             format: BGRA
              width: [ 1, 2147483647 ]
             height: [ 1, 2147483647 ]
          framerate: [ 0/1, 2147483647/1 ]
    video/x-raw:
             format: ABGR
              width: [ 1, 2147483647 ]
             height: [ 1, 2147483647 ]
          framerate: [ 0/1, 2147483647/1 ]
    video/x-raw:
             format: RGB
              width: [ 1, 2147483647 ]
             height: [ 1, 2147483647 ]
          framerate: [ 0/1, 2147483647/1 ]
    video/x-raw:
             format: BGR
              width: [ 1, 2147483647 ]
             height: [ 1, 2147483647 ]
          framerate: [ 0/1, 2147483647/1 ]
    video/x-raw:
             format: GRAY8
              width: [ 1, 2147483647 ]
             height: [ 1, 2147483647 ]
          framerate: [ 0/1, 2147483647/1 ]

Presence – always

Direction – sink

Object type – GstPad

### `src`

    video/x-raw:
             format: GRAY16_LE
              width: [ 1, 2147483647 ]
             height: [ 1, 2147483647 ]
          framerate: [ 0/1, 2147483647/1 ]
    video/x-raw:
             format: GRAY16_BE
              width: [ 1, 2147483647 ]
             height: [ 1, 2147483647 ]
          framerate: [ 0/1, 2147483647/1 ]
    video/x-raw:
             format: RGBx
              width: [ 1, 2147483647 ]
             height: [ 1, 2147483647 ]
          framerate: [ 0/1, 2147483647/1 ]
    video/x-raw:
             format: xRGB
              width: [ 1, 2147483647 ]
             height: [ 1, 2147483647 ]
          framerate: [ 0/1, 2147483647/1 ]
    video/x-raw:
             format: BGRx
              width: [ 1, 2147483647 ]
             height: [ 1, 2147483647 ]
          framerate: [ 0/1, 2147483647/1 ]
    video/x-raw:
             format: xBGR
              width: [ 1, 2147483647 ]
             height: [ 1, 2147483647 ]
          framerate: [ 0/1, 2147483647/1 ]
    video/x-raw:
             format: RGBA
              width: [ 1, 2147483647 ]
             height: [ 1, 2147483647 ]
          framerate: [ 0/1, 2147483647/1 ]
    video/x-raw:
             format: ARGB
              width: [ 1, 2147483647 ]
             height: [ 1, 2147483647 ]
          framerate: [ 0/1, 2147483647/1 ]
    video/x-raw:
             format: BGRA
              width: [ 1, 2147483647 ]
             height: [ 1, 2147483647 ]
          framerate: [ 0/1, 2147483647/1 ]
    video/x-raw:
             format: ABGR
              width: [ 1, 2147483647 ]
             height: [ 1, 2147483647 ]
          framerate: [ 0/1, 2147483647/1 ]
    video/x-raw:
             format: RGB
              width: [ 1, 2147483647 ]
             height: [ 1, 2147483647 ]
          framerate: [ 0/1, 2147483647/1 ]
    video/x-raw:
             format: BGR
              width: [ 1, 2147483647 ]
             height: [ 1, 2147483647 ]
          framerate: [ 0/1, 2147483647/1 ]
    video/x-raw:
             format: GRAY8
              width: [ 1, 2147483647 ]
             height: [ 1, 2147483647 ]
          framerate: [ 0/1, 2147483647/1 ]

Presence – always

Direction – src

Object type – GstPad

## Properties

### alpha

    “alpha” gfloat

Show all pixels (1), only valid ones (0) or something in between

Flags : Read / Write

Default value : 0

### settings

    “settings” gchararray

Camera correction parameters (opaque string of serialized OpenCV objects)

Flags : Read / Write

Default value : NULL

### undistort

    “undistort” gboolean

Apply camera corrections

Flags : Read / Write

Default value : true

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