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Divide two images

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Ariadne MV
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Divide two images

Ariadne MV
Hi,
I'm doing a plugin and I need to divide two images to obtain the RVI (Relative Vegetation Index) and also the NDVI (Normalized Difference Vegetation Index).
The two images correspond to bands of spectrum red, green and NIR.

I have a problem, I call to Calculate division, the result is correct but isn't usefull for me, because the image result is almost all the black.
I read that is a good idea stretching the histogram, but I can't get a good result of this, and I need to see better the image  for select some areas.

Any suggestion?

Thanks!




     
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Nikolay
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Re: Divide two images

Nikolay
Looks like your images is pretty the same, try to enable *32-bit (float)
result* in Image calculator dialog.
x`
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Rogoshchenkov Nikolay


On Mon, Mar 11, 2013 at 8:46 AM, Ariadne MV <[hidden email]> wrote:

> Hi,
> I'm doing a plugin and I need to divide two images to obtain the RVI
> (Relative Vegetation Index) and also the NDVI (Normalized Difference
> Vegetation Index).
> The two images correspond to bands of spectrum red, green and NIR.
>
> I have a problem, I call to Calculate division, the result is correct but
> isn't usefull for me, because the image result is almost all the black.
> I read that is a good idea stretching the histogram, but I can't get a
> good result of this, and I need to see better the image  for select some
> areas.
>
> Any suggestion?
>
> Thanks!
>
>
>
>
>
> --
> ImageJ mailing list: http://imagej.nih.gov/ij/list.html
>

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Ariadne MV
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Re: Divide two images

Ariadne MV
I did it, but the result is similar, the value of all pixels is between 0 and 6 (also some pixels are infinite and NaN)


Other idea?





Thanks!

> Date: Mon, 11 Mar 2013 09:12:54 -0400
> From: [hidden email]
> Subject: Re: Divide two images
> To: [hidden email]
>
> Looks like your images is pretty the same, try to enable *32-bit (float)
> result* in Image calculator dialog.
> x`
> --
> Rogoshchenkov Nikolay
>
>
> On Mon, Mar 11, 2013 at 8:46 AM, Ariadne MV <[hidden email]> wrote:
>
> > Hi,
> > I'm doing a plugin and I need to divide two images to obtain the RVI
> > (Relative Vegetation Index) and also the NDVI (Normalized Difference
> > Vegetation Index).
> > The two images correspond to bands of spectrum red, green and NIR.
> >
> > I have a problem, I call to Calculate division, the result is correct but
> > isn't usefull for me, because the image result is almost all the black.
> > I read that is a good idea stretching the histogram, but I can't get a
> > good result of this, and I need to see better the image  for select some
> > areas.
> >
> > Any suggestion?
> >
> > Thanks!
> >
> >
> >
> >
> >
> > --
> > ImageJ mailing list: http://imagej.nih.gov/ij/list.html
> >
>
> --
> ImageJ mailing list: http://imagej.nih.gov/ij/list.html
     
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Nikolay
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Re: Divide two images

Nikolay
The other idea is to play with limits, try
Image->Adjust->Brightness/Contrast and play with Minimum and Maximum bars.

--
Rogoshchenkov Nikolay


On Mon, Mar 11, 2013 at 11:39 AM, Ariadne MV <[hidden email]> wrote:

> I did it, but the result is similar, the value of all pixels is between 0
> and 6 (also some pixels are infinite and NaN)
>
>
> Other idea?
>
>
>
>
>
> Thanks!
>
> > Date: Mon, 11 Mar 2013 09:12:54 -0400
> > From: [hidden email]
> > Subject: Re: Divide two images
> > To: [hidden email]
> >
> > Looks like your images is pretty the same, try to enable *32-bit (float)
> > result* in Image calculator dialog.
> > x`
> > --
> > Rogoshchenkov Nikolay
> >
> >
> > On Mon, Mar 11, 2013 at 8:46 AM, Ariadne MV <[hidden email]>
> wrote:
> >
> > > Hi,
> > > I'm doing a plugin and I need to divide two images to obtain the RVI
> > > (Relative Vegetation Index) and also the NDVI (Normalized Difference
> > > Vegetation Index).
> > > The two images correspond to bands of spectrum red, green and NIR.
> > >
> > > I have a problem, I call to Calculate division, the result is correct
> but
> > > isn't usefull for me, because the image result is almost all the black.
> > > I read that is a good idea stretching the histogram, but I can't get a
> > > good result of this, and I need to see better the image  for select
> some
> > > areas.
> > >
> > > Any suggestion?
> > >
> > > Thanks!
> > >
> > >
> > >
> > >
> > >
> > > --
> > > ImageJ mailing list: http://imagej.nih.gov/ij/list.html
> > >
> >
> > --
> > ImageJ mailing list: http://imagej.nih.gov/ij/list.html
>
> --
> ImageJ mailing list: http://imagej.nih.gov/ij/list.html
>

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Ariadne MV
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Re: Divide two images

Ariadne MV
Sorry, but I don't understand your last idea.

> Date: Mon, 11 Mar 2013 11:55:20 -0400
> From: [hidden email]
> Subject: Re: Divide two images
> To: [hidden email]
>
> The other idea is to play with limits, try
> Image->Adjust->Brightness/Contrast and play with Minimum and Maximum bars.
>
> --
> Rogoshchenkov Nikolay
>
>
> On Mon, Mar 11, 2013 at 11:39 AM, Ariadne MV <[hidden email]> wrote:
>
> > I did it, but the result is similar, the value of all pixels is between 0
> > and 6 (also some pixels are infinite and NaN)
> >
> >
> > Other idea?
> >
> >
> >
> >
> >
> > Thanks!
> >
> > > Date: Mon, 11 Mar 2013 09:12:54 -0400
> > > From: [hidden email]
> > > Subject: Re: Divide two images
> > > To: [hidden email]
> > >
> > > Looks like your images is pretty the same, try to enable *32-bit (float)
> > > result* in Image calculator dialog.
> > > x`
> > > --
> > > Rogoshchenkov Nikolay
> > >
> > >
> > > On Mon, Mar 11, 2013 at 8:46 AM, Ariadne MV <[hidden email]>
> > wrote:
> > >
> > > > Hi,
> > > > I'm doing a plugin and I need to divide two images to obtain the RVI
> > > > (Relative Vegetation Index) and also the NDVI (Normalized Difference
> > > > Vegetation Index).
> > > > The two images correspond to bands of spectrum red, green and NIR.
> > > >
> > > > I have a problem, I call to Calculate division, the result is correct
> > but
> > > > isn't usefull for me, because the image result is almost all the black.
> > > > I read that is a good idea stretching the histogram, but I can't get a
> > > > good result of this, and I need to see better the image  for select
> > some
> > > > areas.
> > > >
> > > > Any suggestion?
> > > >
> > > > Thanks!
> > > >
> > > >
> > > >
> > > >
> > > >
> > > > --
> > > > ImageJ mailing list: http://imagej.nih.gov/ij/list.html
> > > >
> > >
> > > --
> > > ImageJ mailing list: http://imagej.nih.gov/ij/list.html
> >
> > --
> > ImageJ mailing list: http://imagej.nih.gov/ij/list.html
> >
>
> --
> ImageJ mailing list: http://imagej.nih.gov/ij/list.html
     
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ImageJ mailing list: http://imagej.nih.gov/ij/list.html
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