Use MAT frames as input for feature tracking

Autonomous Machines Jetson & Embedded Systems Jetson Nano
,
1

I’m using C++, NVIDIA VisionWorks Sample for Feature Tracking, and OpenCV 4.1.1

The sample code in main_feature_tracker.cpp takes a string source location as input, and creates a frame source using it →
…
std::string sourceUri = app.findSampleFilePath(argv[1]);
…
std::unique_ptrovxio::FrameSource source(
ovxio::createDefaultFrameSource(context, sourceUri));
…

I would like to modify this or the surrounding code such that I can run a loop and send it frames of the video in the form of MAT images as the input, instead of the current string file location.

3

Hi,

Image input is by default supported by the VisionWorks.

./nvx_demo_feature_tracker [options]

Command Line Options

This topic provides a list of supported options and the values they consume.

-s, --source

  • Parameter: [inputUri]
  • Description: Specifies the input URI. Accepted parameters include a video, an image, an image sequence (in .png, >.jpg, .jpeg, .bmp, or .tiff format), or camera.
  • Usage:
  • --source=/path/to/video.avi for video
  • --source=/path/to/image.png for image
  • --source=/path/to/image_%04d_sequence.png for image sequence
  • --source="device:///v4l2?index=0" for the first V4L2 camera
  • --source="device:///v4l2?index=1" for the second V4L2 camera.
  • --source="device:///nvcamera?index=0" for the GStreamer NVIDIA camera (Jetson TX1 only).

Please download our document here for more information:
https://developer.nvidia.com/embedded/dlc/visionworks-1-6-documentation-for-l4t-27-1

Thanks.

4

Thank you for replying. The issue is that the frames I wish to use aren’t actually physically present as images on the hard drive, so I can’t give a folder location that contains them.
What I want to be able to do is perform some operations on the frames obtained from a video and then pass those frames one by one to the feature tracker.

6