Multi-Sensor Grabber

App that is able to grab videos (in form of image-frames) that are annotated with

• GPS
• Accelerometer
• Gyroscope
• Timestamp

to create low-cost, mobile sequence capturing devices.

Playstore: https://play.google.com/store/apps/details?id=de.weis.multisensor_grabber

Currently implemented

• Acquire rights (camera, gps, etc.)
• Fullscreen app with overlayed button start/stop capturing
• Getting and setting desired image resolution
• Selection of image resolution
• Selection of framerates (10,15,...)
• Frame includes: Timestamp, Image, GPS-data (lat,lon,accuracy,speed)
• Save images to folder, metadata to xml-file

Below is a snippet from an example capture, names are adapted to a database system I use in the backend:

tag	name	meaning
sequence	folder	storage folder on phone
	sensor	identifier of the sensor (here: phone) used
	ts	timestamp when sequence has started
	whitebalance	value the whitebalance has been set to
frame	uri	filename (relative to sequence folder)
	lat	Latitude
	lon	Longitude
	acc	gps accuracy as reported by locationManager
	img_w	width of image
	img_h	height of imgae
	speed	speed in m/s as reported by locationManager
	ts_cam	timestamp of image acquisition
	avelx	angular velocity around x-axis
	avely	angular velocity around y-axis
	avelz	angular velocity around z-axis
	accx	accelerometer value about x-axis
	accy	accelerometer value about y-axis
	accz	accelerometer value about z-axis

<sequence 
    folder="/storage/0000-0000/Android/data/com.example.weis.cv_grabber/files/multisensorgrabber_1482584089332" 
    sensor="samsungSM-G903F" 
    ts="1482584089332" 
    whitebalance="auto"
>
    <Frame 
        uri="IMG_1482584089688.jpg" 
        lat="50.16629447649796" 
        lon="8.658641955498677" 
        acc="48.0" 
        img_w="960" 
        img_h="720" 
        speed="0.0" 
        ts_cam="1482584089688" 
        avelx="-0.11246156692504883" 
        avely="0.05926918238401413" 
        avelz="-0.20069235563278198" 
        accx="9.873687744140625" 
        accy="0.18809446692466736" 
        accz="1.9354127645492554"
    />
    <Frame 
        uri="IMG_1482584089809.jpg" 
        lat="50.16629447649796" 
        lon="8.658641955498677" 
        acc="48.0" 
        img_w="960" 
        img_h="720" 
        speed="0.0" 
        ts_cam="1482584089809" 
        avelx="0.06863339245319366" 
        avely="0.09868396818637848" 
        avelz="-0.20708394050598145" 
        accx="9.767146110534668" 
        accy="-0.00823006872087717" 
        accz="1.6624737977981567"
    />

    ...
</sequence>

TODO

• Implement func to enable user to save all available camera settings and send to me
• Upload functionality and db-integration in backend
• Better control of camera parameters Now using camera2 API
• Settings Activity?
• choose framerate (and implement)
• gps grabbing
• accel/gyro grabbing
• Saving: xml/sqlite ?