Seven Segment Optical Character Recognition
https://github.com/jiweibo/SSOCR 
Digitizes numbers from videos & images of seven segment displays
opencv + python: https://github.com/suyashkumar/seven‑segment‑ocr 

dpavlin@x200:/mnt/nuc/seven-segment-ocr/seven-segment-ocr$ sudo apt-get install python-opencv python-matplotlib

dpavlin@x200:/mnt/nuc/seven-segment-ocr/seven-segment-ocr$ python seven_segment_ocr.py --video /dev/video1 --output /mnt/nuc/Tegra/usb-charging.txt --period 1
VIDEOIO ERROR: V4L2: Pixel format of incoming image is unsupported by OpenCV
Unable to stop the stream: Device or resource busy
VIDEOIO(cvCreateFileCapture_Images (filename)): raised C++ exception:

v4l2-ctl -d /dev/video0 --list-formats

dpavlin@x200:/mnt/nuc/seven-segment-ocr/seven-segment-ocr$ v4l2-ctl -d /dev/video1 --list-formats
ioctl: VIDIOC_ENUM_FMT
        Type: Video Capture

        [0]: 'YUYV' (YUYV 4:2:2)
        [1]: 'H264' (H.264, compressed)
        [2]: 'MJPG' (Motion-JPEG, compressed)