Spectra of film recordings

Here are some 2D spectra of film recordings containing 'chroma patterning'. They are of particular interest because they show, amongst other things, the amount of chrominance energy present at 216 c/aph (essential to the existing Colour Recovery process) and also provide an indication of the extent of geometric distortion and overall 'zoom'.

In the case of the complete episodes, the spectra were generated from a 1000-frame sequence approximately half way through.

The blue graticule lines represent ±4.433 MHz, ±72 c/aph and ±216 c/aph, assuming a 'perfectly framed' picture. Zero frequency is in the middle.

Are You Being Served? - Pilot episode
(after undistorting)



Doctor Who - Planet of the Daleks : Episode 3
(note how weak the 216 c/aph components are)



Doctor Who - The Mind of Evil : Episode 2
(after undistorting)