Working with raw image data

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Revision as of 11:15, 12 January 2018 by Oleg (talk | contribs) (bayer2rgb program)
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Downloading

  • Available options (channels can be 0..3):
# set receiving buffer size in 4kB pages (thus 4096 equals to 16MB)
echo {size} > /sys/devices/soc0/elphel393-mem\@0/buffer_pages_raw_chn2
# start from the N-th frame position in buffer. Currently, 0 or 1
echo 1 > /sys/devices/soc0/elphel393-videomem\@0/video_frame_number
# initiate transfer, wait for X-th frame (X - absolute frame number), 0 = no waiting
echo X > /sys/devices/soc0/elphel393-videomem\@0/membridge_start2
# copy to file
cat /dev/image_raw2 > /tmp/test.raw
# see in hex
hexdump /tmp/test.raw
# copy to PC
scp /tmp/test.raw user@address:/path/
  • Minimal:
echo 4096 > /sys/devices/soc0/elphel393-mem\@0/buffer_pages_raw_chn2
echo 0 > /sys/devices/soc0/elphel393-videomem\@0/membridge_start2
cat /dev/image_raw2 > /tmp/test.raw

Displaying

ImageMagick

  • Camera settings: 2592x1936 JPEG, actual pixels available: 2608x1940
convert -size 2608x1940 -depth 8 -endian MSB -normalize gray:test.raw -compress lzw result.tiff
  • Camera settings: 2592x1936 JP4, actual pixels available: 2592x1936
convert -size 2592x1936 -depth 8 -endian MSB -normalize gray:test.raw -compress lzw result.tiff

The result is a grayscale tiff

bayer2rgb program

bayer2rgb -w 2608 -v 1940 -b 8 -f GRBG -m AHD -t -i test.raw -o test.tiff

The result is a colored image. Pixel values are linear.