Re: image gradient measurement with ImageJ

Posted by Michael Schmid on Apr 02, 2007; 11:00am
URL: http://imagej.273.s1.nabble.com/image-gradient-measurement-with-ImageJ-tp3699884p3699887.html

Hi Juan,

the gradient (aka Sobel filter) is available as
Process -> Find Edges. It is described at
http://rsb.info.nih.gov/ij/docs/menus/process.html

See also
http://en.wikipedia.org/wiki/Sobel

Michael
________________________________________________________________

On 2 Apr 2007, at 03:39, Mike Miller wrote:

> Hello,
>
> My first impression when I think gradient was that you wanted  
> Process ->
> Binary -> Distance Map. But since you mentioned the local variance,  
> try
> Process -> Filters -> Variance...
>
> This second command will change the color each pixel to correspond  
> with the
> variance. You can specify a radius of consideration.
>
> A third consideration might even be able to duplicate the image,  
> perform a
> Gaussian blur and then subtract the two images using Process -> Image
> Calculator. This last technique has proven very noisy for me, but also
> allows more detail through.
>
> I hope one of the last two was helpful.
>
> -Mike
>
> On 3/31/07, Juan Francisco <[hidden email]> wrote:
>>
>> Dear all:
>>   Please i got the following question:
>>   using ImageJ is possible to create the "gradient" image from a  
>> original
>> image?, I mean: for a image given, it would be possible to compute  
>> a map
>> showing the gradient on each pixel of the original image? Gradient  
>> is the
>> local variation of the signal on the image.
>>   Thank you very much!!
>>   Juan Francisco
>>
>>
>> ---------------------------------
>>
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>
>
>
> --
> -Mike