Sample Videos and Projects (four GoPro)

Here you can find sample videos and animations captured with the aid of four GoPro action cameras:

• cam1 and cam2 — GoPro HERO4 Silver
• cam3 and cam4 — GoPro HERO4 Session

        

The following settings were used for recording:

• Resolution: 720p (1280x720)
• FOV: Wide
• FPS: 60

Tip: Short description of overall process of recording and processing can be found in Quick Start Guide for Multiple Action Cameras Configuration.

Camera Optics Calibration Video

Each individual action camera must be calibrated before usage in motion capture session. Below you can find calibration videos (.MP4 files) and results of calibration (.iPiCam files) for each camera:

Camera	Calibration Video (.MP4)	Camera Parameters (.iPiCam)	Recommended Frames for Calibration	Recommended Scale for Undistorting
cam1	↓ cam1-720p-wide.MP4 (13 MByte)	↓ cam1-720p-wide.iPiCam (407 Byte)	50, 880, 1360, 1780, 2110	0.80
cam2	↓ cam2-720p-wide.MP4 (11 MByte)	↓ cam2-720p-wide.iPiCam (410 Byte)	1, 380, 840, 1220, 2016	0.80
cam3	↓ cam3-720p-wide.MP4 (41 MByte)	↓ cam3-720p-wide.iPiCam (412 Byte)	1, 340, 1260, 2420, 2910, 3680, 4490, 5120	0.80
cam4	↓ cam4-720p-wide.MP4 (32 MByte)	↓ cam4-720p-wide.iPiCam (409 Byte)	1, 410, 1100, 1950, 2660, 3320, 3510, 4130	0.80

How to use:

• Download and install iPi Recorder.
• Download .MP4 video files from the above table.
• Run iPi Recorder, click Calibrate Camera Optics in toolbar.
• For each camera (.MP4 video file):
  • Switch to CALIBRATION tab.
  • Click Open Video button in toolbar, choose appropriate video file.
  • Select a few frames for calibration using timeline and Toggle Current Frame button. You can use recommended frames from the above table or choose frames you like.
  • Click Run Calibration button.
  • Now you see results of calibration. You can adjust scale.
  • Save results to .iPiCam file.

For more information see How to Calibrate Camera Optics.

Scene Calibration Sequence

While camera optics calibration is used to determine intrinsic parameters of each camera and can be done once, scene calibration is a process of computing accurate mutual camera positions and orientations in space and should be done for each new cameras setup/configuration. To do it small glowing object called marker is used.

Below you can find individual .MP4 video files from each camera with calibration sequence:

Camera	Video with Marker (.MP4)	Recommended Sync Frame
cam1	↓ calib-cam1.mp4 (5 MByte)	685
cam2	↓ calib-cam2.mp4 (14 MByte)	3743
cam3	↓ calib-cam3.mp4 (25 MByte)	2514
cam4	↓ calib-cam4.mp4 (30 MByte)	1739

How to use:

• Download and install iPi Recorder.
• Download .MP4 video files from the above table.
• Run iPi Recorder, click Build Combined Video in toolbar.
• For each video (i.e. camera) in order from cam1 to cam4:
  • Click Add Video in toolbar, choose appropriate video file.
  • Click on PROPERTIES button in the top area of image from camera.
  • Click Load button in section camera parameters in the left panel, choose appropriate .iPiCam file from the previous section (for example, cam3-720p-wide.iPiCam for calib-cam3.mp4 video).
  • Click Edit button in section sync frame in the left panel, choose the first frame where marker becomes visible (see Recommended Sync Frame column), click Set to Current Frame button in toolbar, switch back to BUILD tab.
• Now video is combined and synchronized but we have to evaluate background (clear scene without marker and moving objects):
  • Choose region on timeline where marker is not visible (for example: from 95 to 665 frames).
  • Click Evaluate Background button in toolbar.
• You're ready to save result to .iPiVideo file:
  • Choose region to be saved: you can save the whole video or only part where marker is visible (for example: from 690 to 6960 frames).
  • Click Save Combined Video button in toolbar.

Below you can find .iPiVideo file created using this procedure:

			↓ Download video file ↓ four-gopro-calibration.iPiVideo 525 MByte
			↓ Download calibration file ↓ four-gopro-calibration.iPiCalib 280 KByte

How to use these files in turn:

• Download and install iPi Mocap Studio.
• Download both above files and put them all in one and the same folder on your hard drive.
• Run iPi Mocap Studio, click Open button or press Ctrl+O and select four-gopro-calibration.iPiCalib file downloaded on the previous step.
• Now you can "play" with resulting calibration data in iPi Mocap Studio.
• If you want to try to process source video file by yourself then:
  • click New button or press Ctrl+N;
  • select four-gopro-calibration.iPiVideo file downloaded before;
  • choose Calibration project type;
  • switch to Calibration tab and push Calibrate button;
  • to adjust scene scale use the following parameters:
    • the height of first camera over ground plane is about 1.12 m

Action Sequence

Coming Soon