split-yuv.sh

#!/bin/sh

# Convert an image to YUV color space, then separating out the
# channels to visual the components of the YUV color space.

# Accept STDIN, use YUV colorspace, separate channels.
#   0. Black
#   1. Y channel
#   2. U channel negated
#   3. U channel
#   4. False-color U channel (0, 1-U, U)
#   5. V channel
#   6. V channel negated
#   7. False-color V channel (V, 1-U, 0)
#   8. Append black, Y channel, false-color U channel, and false-color
#      V channel. Buggy: if we delete black image, the false-colors
#      become greyscale.
#   9. Crop out previous append into four images. Delete the black,
#      then re-append. Dump to STDOUT.
convert - -colorspace YUV -sampling-factor 4:2:2 -separate \
  \( -clone 0 -fill black -colorize 100% \) \
  \( -clone 0 \) \
  \( -clone 1 -negate \) \
  \( -clone 1 \) \
  \( -clone 3 -clone 5 -clone 6 -combine \) \
  \( -clone 2 \) \
  \( -clone 2 -negate \) \
  \( -clone 8 -clone 9 -clone 3 -combine \) \
  -delete 0-2,5-6,8-9 -append \
  -crop '100%x25%' -delete 0 -append -