Panasonic TM700 Camcorder
Observations by John Beale, June 2010
Macbeth color checker comparison charts
Vegas 9e display of TM700 in x.v.Color mode recording full spectrum: screenshot
Extracted Y, Cb, Cr image planes for above full spectrum frame: spectrum.png
(Blue, Green and Red vertical lines at top of spectrum are lines from CFL lamp, for calibration.)
Video showing plot of recorded (Cb, Cr) range, one frame for each Y' value from 0 to 255.
I made a crude measurement of the TM700 Cb and Cr components (the "U, V"
in the H.264 YUV color format) in response to pure color (single
wavelengths) over the visible range, cased on the above spectrum image frame, see below graph. The measured
(min,max) range is Cb: (10,232) and Cr: (28,242) for fully saturated
input colors over the full visible spectrum. The normal limit in YUV
video encoding is (16, 240).
Note, this is a pretty crude measurement, so don't take it too seriously.
The blip in the Cb curve at 436 nm is a mercury line from the CFL lamp; not an issue with sensor response.
|extracting one frame from TM700 output and extracting separate YUV bitmaps:|
ffmpeg -i 20100621_223040.m2ts -ss 00:00:20.254 -vframes 1 outfile.yuv
convert -depth 8 -size 1920x1080+0 gray:outfile.yuv Yplane.png
convert -depth 8 -size 960x540+2073600 gray:outfile.yuv UVplane.png
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