Re: Subtracting G channel from R and B may increase lossless compression?



I was looking for lossless conversion from RGB to YUV but I found out that this kind of conversion isn't possible in a lossless way because of several RGB colors represent the same YUV color (http://www.doom9.org/index.html?/capture/digital_video_color.html). Please could you provide more information about this point?

Thank you very much.

Danilo


"Jim Leonard" <MobyGamer@xxxxxxxxx> wrote in message news:1179930643.817061.276640@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
On May 22, 3:58 pm, "LiloLilo" <danilo.brambi...@xxxxxxxx> wrote:
anybody knows how subtracting G channel from R and from B could increase
lossless compression? I did some tests on some images and found out that
this is true but not for all images. Images with more noise compress worst.
Do you think that subtracting for example the R channel or the B channel
instead of G would be different?

It depends on the source material. Better correlation is always found
if you convert the RGB image into a YUV image (the transform is
reversable; losslessly if you have enough precision).


.



Relevant Pages

  • Re: Question on compression
    ... There are lossless audio codecs, ... doesn't use RGB. ... lossless compression algorithm/codec into the program so that the ...
    (microsoft.public.windowsmedia.encoder)
  • Re: lossless rotation in konqueror
    ... When I rotate an image in Konqueror, is the rotation lossless? ... rotate the images in konqueror -- the images resize on a different ...
    (Debian-User)
  • Re: Damn you, FEDEX! or Nikon D40 lost in Springfield, MO blackhole.
    ... the 2 mp Mavica he had been using with a Nikon D40. ... After shopping around, he got me to order one for him. ... The shipper had it insured, but from what I have read it could take weeks to sort this crap out. ... You may get your insurance from FedEx and a couple weeks later they find it and deliver it. ...
    (alt.photography)
  • Re: Subtracting G channel from R and B may increase lossless compression?
    ... Anybody knows if this conversion is Patent protected? ... Suppose I have now converted my color space from RGB to YUV and let's speak again of channel differencing. ... for lossless colour transform ... this is true but not for all images. ...
    (comp.compression)
  • Re: lossless rotation in konqueror
    ... When I rotate an image in Konqueror, is the rotation lossless? ... rotate the images in konqueror -- the images resize on a different ...
    (Debian-User)