howto remove chroma information ?

[borchers]

Hi,

i've captured an old (10 years) videotape to
restore and archive it to an dvd, the chroma
information is totally gone, there are only
some horizontal red/green bars left, which slowly
move from top to bottom.

if i just grayscale the image using virtual dub, then
the bars can still be seen.

Does anyone know how i can totally remove the chroma information ?
the video was captured using YUY2 color space and morgan's MJPEG
codec.

[^^-+I4004+-^^]

try also "hue/saturation/intensity"(by graft) filter

with PAL system,transfer of color and luma aren't completely separated
-big chroma errors translate also to luma errors.....

[Guest]

I warn you that it is likely that the bars affect the luma channel as well. But if not you might have success processing it using Avisynth and this script:

Tweak(sat=0)

That zeroes out the U and V components.

[borchers]

Hi,

thanks for the replies, i checked all 'other' filters,
and forgot craft's own filters.

removing saturation works well, it seems chroma/luma
separation is fine, cause all bands dissapear when
i set saturation to zero.

for others who read this thread, the filter is here:

http://shelob.mordor.net/dgraft/hue.html

[Guest]

As I said, Tweak(sat=0) is an Avisynth equivalent. It also sets the saturation to 0. You may prefer it to my VirtualDub filter to avoid color space conversions.