Mars images updated 9-16-03

Mark Forsthoefel nous a écrit :

Hi all,
I have updated my web page dedicated to this years Mars apparition.
You can find it at http://home.woh.rr.com/frostdesign/.
If anyone in the group knows what is causing the ocational banding in
my images, as it happens totally at random, could you please post your
answears? This is driving me nuts, as sometime it happens through the
entire nights imaging session, while other nights I don't see it at
all!

I have the same problem with some of my images.
As an example http://images.ciel.free.fr/Images_p/mars12_09.jpg exhibits the
same banding, while http://images.ciel.free.fr/Images_p/mars_03_09.jpg
doesn't show this.
I was wondering whether the image processing could be responsible of this
artifact ?
I use a C8 and a 2x barlow with a ToucamPro, and a 23A red filter.
For the acquiring of the frames, I use Qcfocus (15 im/sec) and the images
are stacked and processed by Registax2.

--
Norbert.

======================================
knowing the universe - stellar and galaxies evolution
http://nrumiano.free.fr
images of the sky http://images.ciel.free.fr
======================================

You could remove those with a Median filter, and sacrifice only minimal
detail.

On Tue, 16 Sep 2003 19:35:04 +0200, "Norbert"
wrote:

I use a C8 and a 2x barlow with a ToucamPro, and a 23A red filter.
For the acquiring of the frames, I use Qcfocus (15 im/sec) and the images
are stacked and processed by Registax2.

You should limit your frame acquisition rate to 5 fps. Higher than
this introduces excessive compression in the download to your
computer. This compression is not "lossless," so you loose detail.
html
font size=3br
       &nbsp ; Wayne Hoffmanbr
33° 49" 17' N  117° 56"  41' Wbr
        "Don't Look Down"br
br
  a href="http://home.pacbell.net/w6wlr/" eudora="autourl"http://home.pacbell.net/w6wlr//a/font/html

WayneH nous a écrit :

On Tue, 16 Sep 2003 19:35:04 +0200, "Norbert"
wrote:

I use a C8 and a 2x barlow with a ToucamPro, and a 23A red filter.
For the acquiring of the frames, I use Qcfocus (15 im/sec) and the
images are stacked and processed by Registax2.

You should limit your frame acquisition rate to 5 fps. Higher than
this introduces excessive compression in the download to your
computer. This compression is not "lossless," so you loose detail.

Thank you for your suggestion. As says Mark, I'll try it next time.

--
Norbert.

======================================
knowing the universe - stellar and galaxies evolution
http://nrumiano.free.fr
images of the sky http://images.ciel.free.fr
======================================

I've tried this, and too much detail is lost, although sometimes it looks
better than the scan lines. I usually just back off the wavelet processing.
It might be that the compression is too great, as I'm getting about 6 FPS,
and if I use the "Stream" mode (30 FPS) instead of Frame mode, I really get
noise! Wayne might be hitting on something here. I will try and back off the
sampleing rate, and see if my images improve.
Mark
"Lunatiki" none wrote in message ...
You could remove those with a Median filter, and sacrifice only minimal
detail.

Depends on the computer and the OS used. On my
Windows ME system, no benefit from a slower frame
rate, it handles 30fps the same as 5fps. On my
Windows 2000 machine, the faster rates generate more
noise. I see absolutely zero added noise on my ME
laptop at the higher rates. I have a feeling that an XP
machine would have the same problem as the 2000
machine. Likely this is due to use of virtual devices in
XP and 2000 versus direct devices in ME.

Thanks, Tom Davis

"WayneH" wrote in message
...
On Tue, 16 Sep 2003 19:35:04 +0200, "Norbert"
wrote:

I use a C8 and a 2x barlow with a ToucamPro, and a 23A red filter.
For the acquiring of the frames, I use Qcfocus (15 im/sec) and the images
are stacked and processed by Registax2.

You should limit your frame acquisition rate to 5 fps. Higher than
this introduces excessive compression in the download to your
computer. This compression is not "lossless," so you loose detail.
html
font size=3br
       &nbsp ; Wayne Hoffmanbr
33° 49" 17' N  117° 56"  41' Wbr
        "Don't Look
Down"br
br
  a href="http://home.pacbell.net/w6wlr/"
eudora="autourl"http://home.pacbell.net/w6wlr//a/font/html

Tom Davis wrote:
Depends on the computer and the OS used. On my
Windows ME system, no benefit from a slower frame
rate, it handles 30fps the same as 5fps. On my
Windows 2000 machine, the faster rates generate more
noise. I see absolutely zero added noise on my ME
laptop at the higher rates. I have a feeling that an XP
machine would have the same problem as the 2000
machine.

Hmmm .. I thought the issue is the rate capability of the USB connection
-- and that the issue is that above a certain frame rate, compression
is added to support the rate.

That would seem to be OS and CPU independent.

Phil

On Tue, 16 Sep 2003 22:20:55 GMT, "Tom Davis"
wrote:

All I know is that I don't have the problem under ME, so who knows
what is going on here.

And that is all that counts, no matter what else is going on...
Wayne Hoffman
33° 49" 17' N 117° 56" 41' W
"Don't Look Down"

http://home.pacbell.net/w6wlr/

Could it be that the something else I refer to may not be
what you think? If 5fps is a rule never to be violated,
why does it work for me at a higher rate. Could it be
that compression is used for all rates, including 5fps,
and something else might be the problem? Phillips
designed the camera to work at higher rates (in fact
15fps is the factory default rate), and I find it to
work fine at the higher rates. Why is this? I
get no banding, no higher level of noise, even when
examining individual frames from both rates in Registax.

When I say I'm stumped here, I mean I'm stumped on
how it can be as you say and not show in my AVI
files. I've had several people basically ram it down
my throat that I should not be using more than 5fps,
so I'm a bit touchy on this subject. I really want some
official reference on this stating that the camera works
this way.

Thanks, Tom Davis

"WayneH" wrote in message
...
On Tue, 16 Sep 2003 22:20:55 GMT, "Tom Davis"
wrote:

All I know is that I don't have the problem under ME, so who knows
what is going on here.

And that is all that counts, no matter what else is going on...
Wayne Hoffman
33° 49" 17' N 117° 56" 41' W
"Don't Look Down"

http://home.pacbell.net/w6wlr/

Mark Forsthoefel wrote:

Hi all,
I have updated my web page dedicated to this years Mars apparition. You can
find it at http://home.woh.rr.com/frostdesign/.
If anyone in the group knows what is causing the ocational banding in my
images, as it happens totally at random, could you please post your
answears? This is driving me nuts, as sometime it happens through the entire
nights imaging session, while other nights I don't see it at all! I Ususally
don't put these banded images on my web page, but you can see them in some
of my earlier images, as well as in the WMVs that are composed of the entire
nights sessions.
Mark


I have had problems with banding when imaging, but it it didnt occur all
the time. I beleive it to be due to artefacts introduced by the stacking
software.
Initially I was using K3ccd tools for capture and processing and
discovered that the final process, which used a 2x enlarged image was
the cause. I only found out when I was testing Registax 2 with the same
avi files. The image produced was smaller, but lacking in artefacts, but
if the image is resized prior to processing, the banding reappeared.
I cant say for certain if this occurs with other software, nor if other
settings in Registax or K3ccd tools will produce it. I dont think frame
rates have had much to do with it in my case as they are fairly constant.
Phil Bishop