Thread Subject: Modulation Transfer function

How can I calculate the Modulation Transfer function for an
image? Thanks.. AZ

On May 8, 10:56=A0pm, "Ahmed Zaki" <azak...@gmail.com> wrote:
> How can I calculate the Modulation Transfer function for an
> image? Thanks.. AZ

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AZ:
You either need the point spread function (and then you just take the
magnitude of the Fourier tranform of the PSF), or you need an image
with a bunch of cycles (e.g. sine waves or black and white line pairs
or different frequencies) that you can measure the contrast of and
build up the MTF frequency by frequency. So which do you have? If
you have neither, you may be out of luck. You might be able to
estimate it if you have a known, perfectly sharp edge in the image
(that gets blurred as it gets imaged). I think you can estimate the
PSF if you have a known point or known edge in your image. What kind
of image do you have?
Regards,
ImageAnalyst

ImageAnalyst <imageanalyst@mailinator.com> wrote in message
<3b7b0902-e3f0-46ba-9e77-
45190e6be339@b1g2000hsg.googlegroups.com>...
> On May 8, 10:56=A0pm, "Ahmed Zaki" <azak...@gmail.com>
wrote:
> > How can I calculate the Modulation Transfer function
for an
> > image? Thanks.. AZ
>
> ----------------------------------------------------------
--------------
> AZ:
> You either need the point spread function (and then you
just take the
> magnitude of the Fourier tranform of the PSF), or you
need an image
> with a bunch of cycles (e.g. sine waves or black and
white line pairs
> or different frequencies) that you can measure the
contrast of and
> build up the MTF frequency by frequency. So which do you
have? If
> you have neither, you may be out of luck. You might be
able to
> estimate it if you have a known, perfectly sharp edge in
the image
> (that gets blurred as it gets imaged). I think you can
estimate the
> PSF if you have a known point or known edge in your
image. What kind
> of image do you have?
> Regards,
> ImageAnalyst


Hi:

If I have an edge and it is blurred in the image, then how
do I estimate the MTF from that image only?
Thanks,
AZ

On May 15, 10:49=A0pm, "Ahmed Zaki" <azak...@gmail.com> wrote:
> ImageAnalyst <imageanal...@mailinator.com> wrote in message
>
> <3b7b0902-e3f0-46ba-9e77-
> 45190e6be...@b1g2000hsg.googlegroups.com>...
>
>
>
>
>
> > On May 8, 10:56=3DA0pm, "Ahmed Zaki" <azak...@gmail.com>
> wrote:
> > > How can I calculate the Modulation Transfer function
> for an
> > > image? Thanks.. AZ
>
> > ----------------------------------------------------------
> --------------
> > AZ:
> > You either need the point spread function (and then you
> just take the
> > magnitude of the Fourier tranform of the PSF), or you
> need an image
> > with a bunch of cycles (e.g. sine waves or black and
> white line pairs
> > or different frequencies) that you can measure the
> contrast of and
> > build up the MTF frequency by frequency. =A0So which do you
> have? =A0If
> > you have neither, you may be out of luck. =A0You might be
> able to
> > estimate it if you have a known, perfectly sharp edge in
> the image
> > (that gets blurred as it gets imaged). =A0I think you can
> estimate the
> > PSF if you have a known point or known edge in your
> image. =A0What kind
> > of image do you have?
> > Regards,
> > ImageAnalyst
>
> Hi:
>
> If I have an edge and it is blurred in the image, then how
> do I estimate the MTF from that image only?
> Thanks,
> AZ- Hide quoted text -
>
> - Show quoted text -

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http://www.google.com/search?hl=3Den&q=3DMTF+edge+response
Best wishes,
ImageAnalyst