Re: Edge Enhancement

Posted by Sidnei Paciornik on
URL: http://imagej.273.s1.nabble.com/Edge-Enhancement-tp5003576p5003584.html

Hi Jan,

Thanks again for the hints, which I did test.

I guess the main drawaback is that these approaches tend to increase high
frequency and contrast everywhere, not only at edges. They give me part of
the improvemente I wanted, but also increasing noise within objects.

Let us see if some other colleague can add to the discussion.

Thank you!

Sidnei


On Sun, Jun 23, 2013 at 5:25 AM, BioVoxxel <[hidden email]> wrote:

> Hi Sidnei,
>
> I am not sure if this will be a solution you are looking for, but have you
> considered unsharp masking (>Process > Filters > Unsharp Mask...).
> Another possibility might be the "Contrast Detection from the BioVoxxel
> Toolbox if you tick the option "enhance edges in original". This method
> applied grayscale erosion and dilation to enhance edges and thereny might
> lead to stronger edge enhancement than the unsharp mask but can also induce
> artifacts if overdone.
>
> kind regards,
> Jan
>
>
> 2013/6/22 Sidnei Paciornik <[hidden email]>
>
>> Hi Jan
>> I guess this is not quite the answer.  I don't need edge detection, but
>> edge enhancement. I couldn't figure how either of your hints would do it.
>> The algorithm should be simple. Take a neighborhood, calculate min, max,
>> and range R.
>> Pick a threshold T.
>> If T>R it is not an edge, keep input pixel.
>> Else exchange pixel with max or min.
>>
>> I just don't know how to program it.
>> Any other hints?
>> Thank you.
>>  Em 22/06/2013 04:24, "Jan Brocher - BioVoxxel" <[hidden email]>
>> escreveu:
>>
>>> Hi Sidnei,
>>>
>>> There is a plugin called Image Edges from Thomas Boudier (I think it is
>>> not included in Fiji by default but available on the following site:
>>> http://imagejdocu.tudor.lu/doku.php?id=plugin:filter:edge_detection:start
>>> ).
>>> Another possibility would be the "Edges" in FeatureJ from Eric Meijering
>>> which enables you to suppress "halo" effects. To my knowledge both plugins
>>> apply Canny edge detection based algorithms.
>>>
>>> regards,
>>> Jan
>>>
>>>
>
>
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