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Area measurement question

Nariman
Hello,

Indeed, during my work, I want to calculate the surface of the particles that were detected.
I don't have a scale bar for the images, so I'm working with pixels unit.
When I measure the area I get numbers such as 0.0015 or 10.45 and so on, I want to say they aren't integer, they are float.
So they aren't the number of pixels? Or Imagej has defined a proposed unit for my measurments?
If yes, someone may tell me how the unit was defined in imagej? I need it to estimate my measurements..

Thank you Chris and thanks in advance to all of you.
Best wishes,
Nariman
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Re: Area measurement question

Michael Schmid
Hi Nariman,

maybe like your camera software provides a spatial calibration that  
is present in the file?
See the Image>Info; you will then see, e.g., 'Resolution:  72 pixels  
per inch'
If the image has a spatial calibration, you should also see scaled  
units instead of pixels in the status line while movint the cursor  
over the image (e.g. x=4.5, y=5.5).

Michael
________________________________________________________________

On 5 Jun 2010, at 15:26, Nariman wrote:

> Hello,
>
> Indeed, during my work, I want to calculate the surface of the  
> particles
> that were detected.
> I don't have a scale bar for the images, so I'm working with pixels  
> unit.
> When I measure the area I get numbers such as 0.0015 or 10.45 and  
> so on, I
> want to say they aren't integer, they are float.
> So they aren't the number of pixels? Or Imagej has defined a  
> proposed unit
> for my measurments?
> If yes, someone may tell me how the unit was defined in imagej? I  
> need it to
> estimate my measurements..
>
> Thank you Chris and thanks in advance to all of you.
> Best wishes,
> Nariman
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Re: Area measurement question

Crescent68
In reply to this post by Nariman
Hello,
I want to calculate particle areas as mm2 or µm. Cam pixel size is 7,40 µm2. I didn’t find distance in pixels and known distance, pixel aspect ratio. ( imagej-analyze-set scale...) How can i measure areas as  µm2. I couldn’t find calibration. İf u can help me, i would be happy.
Best wishes,
Faruk