Yes. And as I was trying to say earlier, there is no law saying that
you have to represent the pixels as read, green and blue values for
the same location to call the data "a picture" or the format an
"image format". The bayer pattern data is just another way to
describe an image. You may actually say that it's a different image
from the RGB data you might convert it to, because the latter also
has some interpolated data - but *of course* the file data represents
a picture!
Sure. Without getting too much into the Foveon vs. Bayer debate,
it should be noted that the Bayer RAW data doesn't produce a unique
RGB image. That's both the advantage and disadvantage of RAW..
Yes. I believe that's right. The article referenced of course presents
the failure to utilise internal interpolation, and that you have to
convert "by hand", as an argument against RAW. I'm thinking that the
ideal format would be a file containing the Bayer data as well as
additional information representing *one possible* transformation - so
that the file might be stored or displayed as RGB without no user
interaction, while you also retained the opportunity to use completely
different interpolation parameters. But maybe they do this already?
more advanced interpolation algorithms could produce better results
than others. With RGB in every pixel, it's a lot more defined (once
you define what R, G, and B mean in a colorimetric sense)
I, personally, think that the Bayer is a good compromise. It
provides luminance information at every pixel location. The chroma is
downsampled (2:1 for G, and 4:1 for B and R). Since that's not too
far from visual perception, it seems like an acceptable way to go.
It seems to me that what exactly constitutes "luminance" is still an
assumption, though. I'm wondering what the results might be like if they
also included some elements with no filter at all. Didn't Fuji or
someone try that, by the way?
Now, if the Foveon-type sensor could have good color rendition with
the same number of sensor sites, then it would be a lot more competitive.
Yes, probably.
And like I said, more or less, if Pentax had bothered, they might
have tried to introduce an extension to the TIFF format allowing the
colour model to be set to, "bayer pattern data" or whatever, and
perhaps rules for transformation to RGB to be stored as TIFF tags...
I think they sorta did that. The TIFF has a number of funky tags
in it. Some are obviously proprietary.
This actually touches on some other recent discussions on the list,
since what you're saying here makes me think that the Pentax engineers
do indeed know what they are doing; taking an existing format and
adapting it just enough to suit your special needs (when there is
nothing available already that does) is good engineering, IMO. Divining
yet another way that's incompatible with everything else to represent a
picture would not be...
Differently put, it seems like Pentax have done this exactly the way I
would have ;-)
But we're discussing minor details here, of course, I must have
little to do these days... Yep, I have, come to think of it; I'm on
sick leave as a result of the fact that I tried something called
"sports" last week...
- Toralf
LOL... I've got so much to do these days, I can't do anything.
I think I know that feeling, too.
Getting ready to fly my airplane to Alaska and try to wear out my
-DS... :)
Sounds like fun ;-)
- Toralf
