"sri" <sresindhu@gmail.com> wrote in message
news:1189746120.215390.8060@g4g2000hsf.googlegroup s.com...
> hi,
> can anyone tell me what is anti-banding in camera?
>
I don't know what your particular camera or software is referring to but I
suspect that it is probably a system to reduce a phenomenon that is a
problem with digital photos when sky or other nearly-a-single-color, large
areas are involved. For example a sky which is nearly a single color with
very subtle variations, when digitized with a palate of colors that may only
have 3 or 4 colors in the range of the colors representing the sky, the sky
will apparently have a band of a single color, next to a band of the next
color, and so on. I have also seen similar problems when an image includes a
large shadowed area where subtle variations in the color of the shadows are
more apparent with bands of color.
These bands become very noticable when the banded area is large and the
image is printed or displayed large. So your anti-banding would possibly be
a piece of software that recognizes and breaks up the banding so that the
bands are not so noticable.
There may be other definitions for anti-banding and I'll leave it to others
to come up with them. And then you will have to decide what seems to fit the
context of where you heard the term.
>
> "sri" <sresindhu@gmail.com> wrote in message
> news:1189746120.215390.8060@g4g2000hsf.googlegroup s.com...
> > hi,
> > can anyone tell me what is anti-banding in camera?
> >
> I don't know what your particular camera or software is referring to
> but I suspect that it is probably a system to reduce a phenomenon
> that is a problem with digital photos when sky or other
> nearly-a-single-color, large areas are involved. For example a sky
> which is nearly a single color with very subtle variations, when
> digitized with a palate of colors that may only have 3 or 4 colors in
> the range of the colors representing the sky, the sky will apparently
> have a band of a single color, next to a band of the next color, and
> so on. I have also seen similar problems when an image includes a
> large shadowed area where subtle variations in the color of the
> shadows are more apparent with bands of color.
>
> These bands become very noticable when the banded area is large and
> the image is printed or displayed large. So your anti-banding would
> possibly be a piece of software that recognizes and breaks up the
> banding so that the bands are not so noticable.
>
> There may be other definitions for anti-banding and I'll leave it to
> others to come up with them. And then you will have to decide what
> seems to fit the context of where you heard the term.
Ummm... Even 8-bit JPEG has 16 million available colors. Rather than
making stuff up, wouldn't it be better to ask the OP for more context?
Paul Allen wrote:
<snip>
>
> Ummm... Even 8-bit JPEG has 16 million available colors. Rather than
> making stuff up, wouldn't it be better to ask the OP for more context?
Banding, as in skies, can occur when the jpg file is
compressed. Most digicams let the user decide how much to
compress a jpg image, usually called an image quality
setting. I haven't heard of it, but it it is possible that
some cameras have compression software that somehow controls
banding. Sounds like a nice idea.
In article <1189746120.215390.8060@g4g2000hsf.googlegroups.co m>,
sri <sresindhu@gmail.com> wrote:
> hi,
> can anyone tell me what is anti-banding in camera?
I believe this has been in use for a few years now. Canon's technical
documents for the first Digital Rebel described a process of reading the
sensor before the shutter is opened. The first read is a form of dark
frame subtraction, but used to offset residual charges that would
introduce noise patterns. Conventional dark frame subtraction seemed to
reduce banding on my old Olys.
There's also another kind of banding caused by poor interpretation of
the sensor's Bayer pattern by the in-camera software. A sharply
contrasting red on green, like flowers, would cause strong patterns of
horizontal lines. It's not seen any more on the better cameras.
On Fri, 14 Sep 2007 19:24:16 GMT
Marvin <physchem@verizon.net> wrote:
> Paul Allen wrote:
> <snip>
> >
> > Ummm... Even 8-bit JPEG has 16 million available colors. Rather
> > than making stuff up, wouldn't it be better to ask the OP for more
> > context?
>
> Banding, as in skies, can occur when the jpg file is
> compressed. Most digicams let the user decide how much to
> compress a jpg image, usually called an image quality
> setting. I haven't heard of it, but it it is possible that
> some cameras have compression software that somehow controls
> banding. Sounds like a nice idea.
What do you know? I grabbed one of my images with lots of sky and
saved it as a 10% quality JPEG. It looks like the compressor
restricted itself to half a dozen distinct shades of blue. Pretty
awful. It's hard to imagine that any camera would let you do that
to an image. I certainly haven't seen anything like that in any
of the cameras I've owned. I generally try to avoid buying dreck,
but perhaps I've been lucky?
I think I'd call what you're talking about a compression artifact
rather than "banding". There is an actual phenomenon called "banding"
in digital cameras. That term is probably used because the effect is
similar to the banding defects that can occur in raster printers and
similar devices. The symptom is horizontal or vertical pattern noise
superimposed on the image. Clogged nozzles on an ink jet printer
will produce banding in the output.
anti-banding 
Linear Mode
