as an area or volume, e.g.
>Thanks to all for the reply. In fact, my aim is to determine the density of
>each object. I thought that I choose the wrong option. Instead of
>calculating integrated density, I should have measure mean gray value which
>shows the density. Correct me please if I am wrong. For the moment, I will
>divide the integrated density values by area values to have the density (or
>mean gray values). Can you kindly tell me what will be the unit of the
>density or gray values here.
>
>Cordially.
>
>Kashif ZEESHAN
>
>-----Message d'origine-----
>De : ImageJ Interest Group [mailto:
[hidden email]] De la part de Ben
>Tupper
>Envoyé : vendredi 29 août 2008 02:52
>À :
[hidden email]
>Objet : Re: Integrated Density?
>
>On Aug 28, 2008, at 12:01 PM, Kashif Zeeshan wrote:
>> Hello experts,
>>
>> Can you kindly help me to understand the term "Integrated Density".
>> I read
>> the documentation of ImageJ which says that this is the sum of all the
>> pixels or equals to the product of Area and Mean Gray Value. But it
>> is very
>> confusing for me. How we will interpret this? What is the
>> difference between
>> density and integrated density in this regard? Is this term
>> "integrated
>> density" is same as "density"? My aim is to compare the different
>> media
>> giving different forms of fungi according to the density of the
>> pellets
>> found in each medium and also if this is possible then I want to
>> classify
>> the pellets in a medium according to the density i.e., I want to
>> classify
>> pellets as less dense, average dense and dense.
>> Any help will be highly appreciated.
>>
>> Kashif ZEESHAN
>
>On Aug 28, 2008, at 7:22 PM, Robert Dougherty wrote:
>
>> Kashif,
>>
>> Maybe this will help: density is an intensive quantity and
>> integrated density is an extensive quantity. See Wikipedia for an
>> explanation of extensive and intensive quantities.
>>
>
>Hi,
>
>I find it a bit hard to untangle the questions posed. But here are
>couple of thoughts...
>
>(1) Be sure that you understand what the documentation actually says,
>"The sum of the values of the pixels in the image or selection." In
>your case, it means that it sums the gray values of each pellet found
>- it is a measure of "grayness" on an individual particle or
>selection. (see
http://rsb.info.nih.gov/ij/docs/menus/analyze.html#set )
>
>(2) Your description of pellet counting could be used to measure a
>density of population - for example, X pellets per square cm. You can
>use ImageJ for this purpose. For that you could analyze the image
>and retrieve either the number of pellets found. Dividing the pellet
>count by the image area will give you the population density. If you
>want to discriminate density patterns within an image, then you might
>want to dig deeper by retrieving the centroids of each pellet. You
>could divide the image into quadrants of known area and get the
>population density in each quadrant, etc.
>
>If I follow you correctly, I don't think you want the Integrated
>Density as you won't care how dark each pellet is.
>
>Cheers,
>Ben
>
>
>
>Ben Tupper
>Bigelow Laboratory for Ocean Science
>180 McKown Point Road
>POB 475
>West Boothbay Harbor, ME 04575