Re: filmscanners: image samples of digital artifacts

[rafeb <rafeb@channel1.com>]

At 10:48 AM 7/20/01 +0000, Lynn wrote:
>Rafe wrote:
>
>>>The sky in the "Prarie" photo looks smooth as silk
>>>on my PC, with 24 bit video.  With the screen set
>>>to "256 colors" I get topo maps in the sky.
>
>and Bob wrote:
>>Thanks Rafe.  Mine looked smooth as silk too.  I couldn't figure out >what 
>>I was suppose to be seeing and wasn't.  Now I get it.
>
>OK, I'm not exactly sure what's going on here, that one display set to 
>factory specs (mine) shows posterization in an Internet JPEG, and two others 
>(Rafe's and Bob's) do not.
>
>Should Internet picture postings come with the caveat, "Warning, This 
>Picture Must Be Viewed At 48-Bits!"?  That doesn't sound altogether 
>realistic, to me. :-)


I'm viewing it at 24 bits and it's fine.

The one video option that's not acceptable is 
"256 colors".  This is also refered to as 
"indexed color."

Now it's also possible that the video driver 
or software in Dan's notebook is *using* 
an indexed-color mechansim while appearing 
to operate as "16-bit TrueColor."

This is where you may need to dig deeper 
into the tech details of your video hardware.
And of course the vendor/manufacturer of that 
notebook may not be altogether up-front with 
the necessary details.

I think there's a good deal of evidence 
to indicate that notebook computers, with 
LCD screens, are poorly suited to viewing 
and/or editing color graphics.  This is 
asking for trouble.

In your case, Lynn, I'm more puzzled.  
Can you describe the hardware and software options 
on the system you're using that yields posterization
on the "Tibet" jpg?


rafe b.