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Re: Two pixel values !!!

Posted by Michael Schmid on Jul 18, 2011; 12:26pm
URL: http://imagej.273.s1.nabble.com/Two-pixel-values-tp3683840p3683843.html

Hi Sylvain,

looks like your images have originally signed 16 bit values. ImageJ  
has no signed 16 bit data type, so it just takes them as unsigned and  
adds a calibration function to convert them to signed. Some plugins  
use that calibration function, some don't.

You can use Analyze>Calibrate and select function 'none' to remove  
that calibration, then you will always have values between 0 and 65535.

The other alternative is converting everything to float (32 bit),  
then you can have true signed numbers.

Michael
________________________________________________________________

On 18 Jul 2011, at 14:14, Sylvain Cantaloube wrote:

> Hi,
>
> I have a problem with my image files from DeltaVision (Managed with  
> SoftWork)
>
> Whan i open my file with ImageJ, pixel values appear like that :  
> value=x (x+32768)
>
> Thus, I have two pixel values :
> - The normal pixel value
> - This same value plus 32768
>
> The problem is : for some operations (Threshold, B&C...) ImageJ  
> takes in account the first value, for others (3D Object Counter  
> plugin) it takes the second value.
>
> I would like to delete the second value in my image files but i  
> don’t know how...
>
> I put an example at thes link :
>
> http://xfer.curie.fr/get/ 
> 0DPxW0CsPv8/20110712_3T3PAF_miNEG_72h_01_22_R3D.dv
> http://xfer.curie.fr/get/uaonAwJffQV/ 
> 20110712_3T3PAF_miNEG_72h_01_22_R3D.dv.log
>
> If someone have a solution...
>
> Best,
>
> Sylvain Cantaloube
> UMR 218 du CNRS