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Re: Integrated Pixel Density Units

Posted by MODEL, MICHAEL on Jan 06, 2015; 6:03pm
URL: http://imagej.273.s1.nabble.com/Integrated-Pixel-Density-Units-tp5011086p5011097.html

Hazel,
Your Min and Max are the same, are measuring a single pixel?


-----Original Message-----
From: ImageJ Interest Group [mailto:[hidden email]] On Behalf Of May, Hazel - (hazelmay)
Sent: Tuesday, January 06, 2015 12:15 PM
To: [hidden email]
Subject: Re: Integrated Pixel Density Units

Thank you,

Another question however; my images were in inches as it appears. I have changed this to microns Now values are huge – due to the conversion obviously

I also changed the scaled of the pixel width and height.  To 1.0 and 0.1 microns and this alters my original values.

If I were to graphy my results would and now I have gigantic numbers

With inches and I have done analysis I get these results summary:

Slice                                                                                       Count    total area          avg size  %area   mean                    IntDen
362686_30_RIGHT_PAAP_SILVER_20X-1.tif         16004    49.323                   0.003     9.086    137.340                 0.378

However in the results I get:

                 Area                   mean   StdDev    Min        Max      IntDen   %Area   RawIntDen
16004    1.085E-4               144         0              144         144         0.016     100         144

Those are all when the images are in inches

Now when I have them in Microns
The Summary

Slice                                                                                       Count    total area                        avg size                %area      mean         IntDen
362686_30_RIGHT_PAAP_SILVER_20X-1.tif         16004    47103308932.719              2943221.003       9.086     137.340      360729529.321



Results
                 Area                   mean   StdDev    Min        Max      IntDen                   %Area   RawIntDen
16004    103623.280          144         0              144         144         14921752.276     100         144

Im Struggling to interpret the results here I was told to take the IntDen from the summary and not the results…but they ‘re different numbers Plus I am not following the  1/unit^2 means..
Say unit being inches or microns. Is it a specific measurement of either unit?

Sorry If I am asking basic questions or not being clear.
I Just don’t know what I don’t know.

Many Many Thanks

Hazel

-----Original Message-----
From: ImageJ Interest Group [mailto:[hidden email]] On Behalf Of Michael Sarahan
Sent: Monday, January 05, 2015 9:57 PM
To: [hidden email]
Subject: Re: Integrated Pixel Density Units

Hi Hazel,

These numbers may express the percentage of integrated intensity represented by any given region.  Do you have something on the order of 100 regions in your image?  The tutorial at:
http://imagej.nih.gov/ij/docs/examples/dot-blot/ suggested this, which I found by looking at the Integrated Density entry at:
http://rsbweb.nih.gov/ij/docs/guide/146-30.html

I hope this helps.
Michael


On Mon, Jan 5, 2015 at 7:51 PM, May, Hazel - (hazelmay) < [hidden email]> wrote:

> Dear Sir/Madam
>
> I am having trouble establishing the units of integrated Pixel Density.
> So far I have analysed an 8-bit image with subtracted background and
> has a threshold of 0-255 of silver stained rat brain tissue.
> I know so far that pixel density is the sum of all the pixels in the
> given analysed area...
> But what are the units? When you get results summary, you get at 0.8
> or
> 0.988 or 0.33 or even 1.23 - but in what?
>
> Many thanks,
> Hazel May
>
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> ImageJ mailing list: http://imagej.nih.gov/ij/list.html
>

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