# Camera streaming using OpenCV
The **gst-camera-opencv-resize.py** application uses OpenCV APIs to capture a camera frame from a live camera stream and then apply color conversion or re-size the frame. The re-sized output is displayed on the screen.
**Figure : gst-camera-opencv-resize.py pipeline**
## Run the application on the target device
1. Ensure that you complete the [Prerequisites](https://docs.qualcomm.com/doc/80-80022-55/topic/prerequisites-for-python-sample-applications.html).
2. Run the application with input from a live camera.
gst-camera-opencv-resize.py --inwidth 1280 --inheight 720 --outwidth 640 --outheight 480
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The stream is displayed on the screen.
## Expected output
**Figure : Expected output for gst-camera-opencv-resize.py**
## Troubleshoot GTK backend failure in root mode
When you run a GTK-based application as the `root`, GTK may fail to initialize the backend because it cannot access the active display session from the root runtime context. To resolve this issue, explicitly export the active display session so that the root process can connect to the correct display and initialize the GTK backend successfully. For example, you can export the active display session environment variables before running the `adb root`.
>
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> export XDG_RUNTIME_DIR=/run/user/1000
> export WAYLAND_DISPLAY=wayland-1
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## Pipeline flow
The following table lists the plugins used to run the camera streaming with OpenCV pipeline:
| Plugin | Description |
| --- | --- |
| [qtiqmmfsrc](https://docs.qualcomm.com/doc/80-80022-50/topic/qtiqmmfsrc.html) | Captures the video stream and feeds it into the capsfilter. |
| capsfilter | Enforces constraints on the raw video data. |
| queue | Puts the video data in a queue till the buffer limit is met. |
| [qtivtransform](https://docs.qualcomm.com/doc/80-80022-50/topic/qtivtransform.html) | Transforms the video data.
After transformation, capsfilter is applied again. |
| [waylandsink](https://docs.qualcomm.com/doc/80-80022-50/topic/waylandsink.html) | Displays the video stream on the Wayland display. |
## Related information
[Single camera streaming](https://docs.qualcomm.com/doc/80-80022-55/topic/gst-camera-single-stream-example.html)
Last Published: May 17, 2026
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