Eyesis4Pi data structure
From ElphelWiki
Contents
Intro
Eyesis4Pi stores images and gps/imu logs independently.
| Data | Stored on | Comments |
|---|---|---|
| Images | Host PC or (9x) internal SSDs (if equipped) | |
| IMU/GPS logs | Internal Compact Flash cards (2x16GB) |
IMU/GPS logs
Description
A sensor's log is a list of registered events from various sources:
- Trigger for starting image exposure (fps)
- IMU sentence received (2460 samples per second)
- GPS sentence received (5 samples per second) - in NMEA or other configured format.
Logs are stored in a binary format to have smaller size. Also, there's a file size limit - when it's reached a new file with an auto-incremented index will be started.
Raw logs examples
All the raw *.log files are found here
Parsed log example
parsed_log_example.txt (41.3MB) at the same location
[localTimeStamp,usec]: IMU: [gyroX] [gyroY] [gyroZ] [angleX] [angleY] [angleZ] [accelX] [accelY] [accelZ] [veloX] [veloY] [veloZ] [temperature] [localTimeStamp,usec]: GPS: $GPRMC,231112.8,A,4043.36963,N,11155.90617,W,000.00,089.0,250811,013.2,E [localTimeStamp,usec]: SRC: [masterTimeStamp,usec]=>1314335482848366 [localTimeStamp,usec]=>1314335474855775
Tools for parsing logs
Download one of the raw logs.
- PHP: Download read_imu_log.php_txt, rename it to *.php and run on a PC with PHP installed.
- Java: Download IMUDataProcessing project for Eclipse.
Images
Description
The pictures from each image sensor are stored in 8 triplets (because 3 sensors are connected to a single system board for the 24-sensor equipped camera) in the RAW JP4 format.
 JP4 file opened as JPEG - sample from the master camera. Download original JP4 Open in an online EXIF reader |
Each triplet when post-processed in ImageJ plugin, cut and re-oriented is a vertical segment of a panorama.
