Halo effect of TEM Images

[Thomas Sadowski]

Hello all,
 
 
My name is Tom Sadowski and I am a student at Southern Connecticut State University. I am currently involved in a study the is analyzing the sizes PT nanopaticles. Our imaging modality is TEM and images were captured using a CCD camera. We are noticing that the resulting digital images have a halo of lighter gray scale value which we think is from the saturation of the CCD camera due to high res electron beam. Please see attached URL:
 
 
http://home.southernct.edu/~sadowskit1/
 
 
Does anyone have any suggestions on how to remove this haloing??? We are finding that it tends to result in "noisy" binary images.
 
 
Thank you in advance,
 
Thomas Sadowski
Southern Connecticut State University
 
_________________________________________________________________
Express yourself instantly with MSN Messenger! Download today it's FREE!
http://messenger.msn.click-url.com/go/onm00200471ave/direct/01/

[Wayne Rasband]

The Process>Subtract Background command, with the default radius of 50,
appears to remove the halo.

-wayne

On Jun 16, 2006, at 10:11 AM, Thomas Sadowski wrote:

> Hello all,
>
>
> My name is Tom Sadowski and I am a student at Southern Connecticut
> State University. I am currently involved in a study the is analyzing
> the sizes PT nanopaticles. Our imaging modality is TEM and images were
> captured using a CCD camera. We are noticing that the resulting
> digital images have a halo of lighter gray scale value which we think
> is from the saturation of the CCD camera due to high res electron
> beam. Please see attached URL:
>
>
> http://home.southernct.edu/~sadowskit1/
>
>
> Does anyone have any suggestions on how to remove this haloing??? We
> are finding that it tends to result in "noisy" binary images.
>
>
> Thank you in advance,
>
> Thomas Sadowski
> Southern Connecticut State University

[Harry Parker]

One thought occured to me:  Image sharpening algorithms can cause these kinds of halos.  These sharpening algorithms are often on by default in digital cameras. Have you checked that any sharpening done by the camera has been turned off?

Thomas Sadowski <[hidden email]> wrote: Hello all,
 
 
My name is Tom Sadowski and I am a student at Southern Connecticut State University. I am currently involved in a study the is analyzing the sizes PT nanopaticles. Our imaging modality is TEM and images were captured using a CCD camera. We are noticing that the resulting digital images have a halo of lighter gray scale value which we think is from the saturation of the CCD camera due to high res electron beam. Please see attached URL:
 
 
http://home.southernct.edu/~sadowskit1/
 
 
Does anyone have any suggestions on how to remove this haloing??? We are finding that it tends to result in "noisy" binary images.
 
 
Thank you in advance,
 
Thomas Sadowski
Southern Connecticut State University
 
_________________________________________________________________
Express yourself instantly with MSN Messenger! Download today it's FREE!
http://messenger.msn.click-url.com/go/onm00200471ave/direct/01/


--  
Harry Parker  
Senior Systems Engineer  
Dialog Imaging Systems, Inc.
 
---------------------------------
Yahoo! Groups gets better. Check out the new email design. Plus there’s much more to come.  

[Divakar Ramachandran]

Hi Tom,

It would be better to re-record these images. The "halo" is because of uneven illumination - spread out the beam so that you have a  uniform illumination across the screen. And, if you plan to use these images for size distribution determination, I think the focus requires a little adjustment a well.

HTH,
Divakar


Wayne Rasband <[hidden email]> wrote: The Process>Subtract Background command, with the default radius of 50,
appears to remove the halo.

-wayne

On Jun 16, 2006, at 10:11 AM, Thomas Sadowski wrote:

> Hello all,
>
>
> My name is Tom Sadowski and I am a student at Southern Connecticut
> State University. I am currently involved in a study the is analyzing
> the sizes PT nanopaticles. Our imaging modality is TEM and images were
> captured using a CCD camera. We are noticing that the resulting
> digital images have a halo of lighter gray scale value which we think
> is from the saturation of the CCD camera due to high res electron
> beam. Please see attached URL:
>
>
> http://home.southernct.edu/~sadowskit1/
>
>
> Does anyone have any suggestions on how to remove this haloing??? We
> are finding that it tends to result in "noisy" binary images.
>
>
> Thank you in advance,
>
> Thomas Sadowski
> Southern Connecticut State University

---------------------------------
 Divakar@Yahoo
---------------------------------

 
---------------------------------
  Yahoo! India Answers: Share what you know. Learn something new Click here
 Send free SMS to your Friends on Mobile from your Yahoo! Messenger Download now