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Measuring focus / sharpness

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Measuring focus / sharpness

David Faulstich Diniz Reis
7 posts
Hi!

 

I want to know IF anyone already made na algorithm to measure the image´s
sharpness.

 

I am trying to automatically apply an sharpness algorithm if needed.

 

Reading I discover that we need to discover the spatial frequency. Mesure
high spatial frequency / low frequency, and based on this result, apply the
sharpness algorithm.

 

Thank you in advance.

 

David

 

www.infosolo.com.br

[hidden email]

+55-61-33236808

 
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Re: Measuring focus / sharpness

Andreas Maier
12 posts
Hi,

usually you need an edge in the image to measure the "sharpness". Form
an edge you could estimate the modulation transfer function.
Do your images share a certain characteristic (as a certain edge) ?

Best,

Andreas

Am 7/1/2010 11:41 AM, schrieb David Faulstich Diniz Reis:

> Hi!
>
>
>
> I want to know IF anyone already made na algorithm to measure the image´s
> sharpness.
>
>
>
> I am trying to automatically apply an sharpness algorithm if needed.
>
>
>
> Reading I discover that we need to discover the spatial frequency. Mesure
> high spatial frequency / low frequency, and based on this result, apply the
> sharpness algorithm.
>
>
>
> Thank you in advance.
>
>
>
> David
>
>
>
> www.infosolo.com.br
>
> [hidden email]
>
> +55-61-33236808
>
>
>
>    


--
Dr.-Ing. Andreas Maier
Stanford University
Department of Radiology
The Lucas Center for Imaging
Mail Code 5488, Route 8
Stanford, CA  94305
http://med.stanford.edu/profiles/Andreas_Maier/
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RES: Measuring focus / sharpness

David Faulstich Diniz Reis
7 posts
The pictures are scanned documents.

I need to validate the scanned document.

I think all the document have edges. :-)

The MTF plugin could help me?
<a href="http://rsb.info.nih.gov/ij/plugins/download/mtf/MeasureMTF_.html#measureMTF%">http://rsb.info.nih.gov/ij/plugins/download/mtf/MeasureMTF_.html#measureMTF%
28ij.ImagePlus%29



Thanks!

-----Mensagem original-----
De: Andreas Maier [mailto:[hidden email]]
Enviada em: quinta-feira, 1 de julho de 2010 16:08
Para: ImageJ Interest Group
Cc: David Faulstich Diniz Reis
Assunto: Re: Measuring focus / sharpness

Hi,

usually you need an edge in the image to measure the "sharpness". Form
an edge you could estimate the modulation transfer function.
Do your images share a certain characteristic (as a certain edge) ?

Best,

Andreas

Am 7/1/2010 11:41 AM, schrieb David Faulstich Diniz Reis:

> Hi!
>
>
>
> I want to know IF anyone already made na algorithm to measure the image´s
> sharpness.
>
>
>
> I am trying to automatically apply an sharpness algorithm if needed.
>
>
>
> Reading I discover that we need to discover the spatial frequency. Mesure
> high spatial frequency / low frequency, and based on this result, apply
the

> sharpness algorithm.
>
>
>
> Thank you in advance.
>
>
>
> David
>
>
>
> www.infosolo.com.br
>
> [hidden email]
>
> +55-61-33236808
>
>
>
>    


--
Dr.-Ing. Andreas Maier
Stanford University
Department of Radiology
The Lucas Center for Imaging
Mail Code 5488, Route 8
Stanford, CA  94305
http://med.stanford.edu/profiles/Andreas_Maier/