adjust contrast in a ROI

[John Alexander-7]

Hello ImageJ group ...

I seem to be having difficulty in figuring out how to adjust the
contrast in a ROI.

I have an image (of a gel) and the ladder is faint. I just wish to box
the ladder and enhance the contrast to make it more visible without
adjusting the rest of the image.

I am sure this is easy ... but I am failing to see how it is done ...

One thing I tried is to "duplicate" the ladder into a new image, adjust
the contrast, then copy/paste it back in position.  This doesn't work at
all.

I next "duplicated" the ladder, adjusted the contrast, converted it to
32 bit then back to 16 bit.  Then, I could copy/paste it back into
position and it looks how I wanted.

Is there a more elegant solution?

J

[picheral]

>Hello,

I've been using ImageJ for months. I did compress
TIF images in ZIP using the ImageJ "save as"
tool. I did get a 80% compression ratio till
yesterday and today it's only 20%. Is there any
possibility to adjust the Zipping ratio in ImageJ ?

Marc P.



----------------------------------------------------------------------------------
VISIT our WEB site !

http://www.obs-vlfr.fr/LOV/ZooPart/
----------------------------------------------------------------------------------

Marc PICHERAL, ingenieur
Laboratoire d'Océanologie de Villefranche sur mer
CNRS UPMC UMR7093
Observatoire Océanologique de Villefranche-sur-Mer
Station Zoologique
La Darse
BP 28
06234 Villefranche sur mer
Tel : [phone]
Fax: [phone]  

[Bill Mohler]

John-

You need to hit the Apply button in the B/C dialog to "hardcopy" your
duplicated version of the ladder.  Then you can paste it back on your
original image.

Bill

>Hello ImageJ group ...
>
>I seem to be having difficulty in figuring out how to adjust the
>contrast in a ROI.
>
>I have an image (of a gel) and the ladder is faint. I just wish to box
>the ladder and enhance the contrast to make it more visible without
>adjusting the rest of the image.
>
>I am sure this is easy ... but I am failing to see how it is done ...
>
>One thing I tried is to "duplicate" the ladder into a new image, adjust
>the contrast, then copy/paste it back in position.  This doesn't work at
>all.
>
>I next "duplicated" the ladder, adjusted the contrast, converted it to
>32 bit then back to 16 bit.  Then, I could copy/paste it back into
>position and it looks how I wanted.
>
>Is there a more elegant solution?
>
>J

[Balazs Nyiri]

 I am not really sure what your image and the? "ladder" are,
but a possibility could be to select the portion of the image
you want to change and apply an operation to the selection
from "Process|Math|xxx". To me "Process|Math|Gamma..."
works well (with a Gamma below one) for what I need.

Balazs


 


 

-----Original Message-----
From: John Alexander <[hidden email]>
To: [hidden email]
Sent: Fri, 21 Mar 2008 10:20 am
Subject: adjust contrast in a ROI










Hello ImageJ group ...

I seem to be having difficulty in figuring out how to adjust the
contrast in a ROI.

I have an image (of a gel) and the ladder is faint. I just wish to box
the ladder and enhance the contrast to make it more visible without
adjusting the rest of the image.

I am sure this is easy ... but I am failing to see how it is done ...

One thing I tried is to "duplicate" the ladder into a new image, adjust
the contrast, then copy/paste it back in position.  This doesn't work at
all.

I next "duplicated" the ladder, adjusted the contrast, converted it to
32 bit then back to 16 bit.  Then, I could copy/paste it back into
position and it looks how I wanted.

Is there a more elegant solution?

J