Implementation of synchronized multi camera video capture on an embedded system

Abstract

A light field array consists of multiple cameras that capture frames at the same time. Frame synchronization is necessary to ensure that all the cameras capture the scene at the same instant. The aim of this project was to implement a multi camera system based on an NVIDIA Jetson TX2 microcontroller. The cameras used were from Leopard Imaging, where the MIPI interface was used to trigger the cameras. The available cameras and adapter board do not support frame synchronization in hardware, so the aim of this thesis was to minimise the discrepancy between the cameras as much as possible. Several tests were conducted to ensure that the system is functioning correctly and to investigate the synchronization error between the frames obtained from each camera. Furthermore, a user interface with physical buttons was implemented replacing the usual mouse and keyboard. This makes the system more portable and user friendly. The tests were performed by capturing frames of two types of clock animations. First, images of an analogue clock were captured and the discrepancy between the frames were indicated by the difference in the position of the second hand. Another set of tests were conducted by capturing frames of a digital stopwatch. The synchronization error between the cameras was obtained by calculating the difference between the times recorded in the frames. Furthermore, when possible, the software used, tracked the timestamps of the captured frames. The difference between the recorded timestamps resulted in the error between the cameras. These tests were performed up to ten times so that an average of the synchronization error could be calculated.