At 11:10 PM 8/23/2012, [email protected] wrote:
In reply to Terry Blanton's message of Wed, 22 Aug 2012 21:15:15 -0400:
Hi,
[snip]
>Dead moving pixies?
>
>http://www.dailymail.co.uk/sciencetech/article-2192008/Are-Martian-
overlords---just-dead-pixels-camera-Images-beamed-Curiosity-lead-talk-UFOs-Mars.html
>
>T
..surely if they were dead pixels they would be at the same position
relative to
the frame in each image?
Clearly that is not only not the case, but pixels there were "dead"
in one image
are suddenly "live" again in the next????
Yes. Pixels in image sensors can be marginal or noisy, plus we may be
seeing artifacts of how images are combined from pixels. Analysis of
the raw data would show, through statistical analysis.
The "frame," because of vibration, may not be eactly the same with
each frame capture.
How bright are stars on Mars? A star might raise the level of a pixel
closer to flipping the bit. It might never be able to flip two
pixels, if the image is sharp.
Trying to figure this out from jpeg files can be ridiculous, because
of compression and loss of primary pixel data. One would want the raw
data. And it's quite possible that image compression has taken place
on Mars, so that the necessary data transmission is reduced.
I would guess that Mission Control is capable of testing this all.
The positions of bright stars would be known, for example. I guess
they could arrange transmission of some block of primary image data.
If it's worth it! Is it?
