Get Screenshot
(HTC AMAZE is 544x960)
adb pull /dev/graphics/fb0
ffmpeg -vframes 1 -f rawvideo -pix_fmt rgb32 -s 544x960 -i fb0 screenshot.png

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It’s important to have the correct resolution
This is my PengPod
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sudo adb pull /dev/graphics/fb0
avconv -vframes 1 -f rawvideo -pix_fmt rgb32 -s 800x480 -i fb0 screenshot.png
display screenshot.png

Display Random Static to Screen
cat /dev/urandom > /dev/graphics/fb0

Save Screenshot while on Device
cat /dev/graphics/fb0 > screenshot

Save Screenshot while on Device
cat screenshot  > /dev/graphics/fb0