Re: Edge Enhancement

Posted by BenTupper on
URL: http://imagej.273.s1.nabble.com/Edge-Enhancement-tp5003576p5003585.html

Hi,

On Jun 23, 2013, at 3:11 PM, Sidnei Paciornik wrote:

> 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.


Can you post a small example in a public place so we can see what you are describing?

Thanks,
Ben

>
> 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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>
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