plot profile problems with pixel value

[Rigo Pantoja]

All,

The plot profile (Ctrl+K)  is yielding different values for the same pixel.
I Noticed this when I generated plot profiles for an individual spot along
the x and y axis.   The  peak  pixel  value was different for the comon
interesection.  Also, if you generate a various plot profiles for with
increasing lengths, the peak pixel value changes.  Can this bug be fixed?

Thanks,

Rigo

[Harry Parker]

Have you tried deselecting the menu option, Edit->Options->Profile Plot Options...->Interpolate Line Profiles?
 
--  
Harry Parker  
Senior Systems Engineer  
Digital Imaging Systems, Inc.

----- Original Message ----
From: Rigo Pantoja <[hidden email]>
To: [hidden email]
Sent: Wednesday, April 9, 2008 2:35:21 PM
Subject: plot profile problems with pixel value

All,

The plot profile (Ctrl+K)  is yielding different values for the same pixel.
I Noticed this when I generated plot profiles for an individual spot along
the x and y axis.   The  peak  pixel  value was different for the comon
interesection.  Also, if you generate a various plot profiles for with
increasing lengths, the peak pixel value changes.  Can this bug be fixed?

Thanks,

Rigo




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[Rigo Pantoja]

Hi Harry,

Wayne recommened your suggestion.  It did not work.

Basically, when you zoom in and draw a line across a set of linear pixels,
you get a variable reading of the pixel value if the line does not cross the
pixel in the exact center.  If your pixels values are high you might not
notice.  However, if you are analyzing single-molecues - where every count
matters - this becomes obvious.

If you follow the thread you can see this effect with a sample image
(fluorescentcells), which after you convert it to a 16bit tiff file.

Thanks,

Rigo

On Thu, Apr 10, 2008 at 10:34 AM, Harry Parker <[hidden email]>
wrote:

> Have you tried deselecting the menu option, Edit->Options->Profile Plot
> Options...->Interpolate Line Profiles?
>
> --
> Harry Parker
> Senior Systems Engineer
> Digital Imaging Systems, Inc.
>
> ----- Original Message ----
> From: Rigo Pantoja <[hidden email]>
> To: [hidden email]
> Sent: Wednesday, April 9, 2008 2:35:21 PM
> Subject: plot profile problems with pixel value
>
> All,
>
> The plot profile (Ctrl+K)  is yielding different values for the same
> pixel.
> I Noticed this when I generated plot profiles for an individual spot along
> the x and y axis.   The  peak  pixel  value was different for the comon
> interesection.  Also, if you generate a various plot profiles for with
> increasing lengths, the peak pixel value changes.  Can this bug be fixed?
>
> Thanks,
>
> Rigo
>
>
>
>
> __________________________________________________
> Do You Yahoo!?
> Tired of spam?  Yahoo! Mail has the best spam protection around
> http://mail.yahoo.com
>

[Jonathan Hilmer]

I think the problem you're seeing arises from the spatial definitions
and representations of each pixel.  Rather than go through a lengthy
explanation, try using the point selection tool and Measurements
(which will give the same results as Plot Profile and is faster to
check) when zoomed in.  You'll see the effect causing your results,
which actually arises from a very methodical way of processing the
pixelated data.

The slight difference I see between the point selection tool and line
selections is that the line selections seems to go to the nearest
pixel "corner" for a measurement while the point selection is always
to the upper-left.

Jonathan


On Thu, Apr 10, 2008 at 2:14 PM, Rigo Pantoja <[hidden email]> wrote:

> Hi Harry,
>
>  Wayne recommened your suggestion.  It did not work.
>
>  Basically, when you zoom in and draw a line across a set of linear pixels,
>  you get a variable reading of the pixel value if the line does not cross the
>  pixel in the exact center.  If your pixels values are high you might not
>  notice.  However, if you are analyzing single-molecues - where every count
>  matters - this becomes obvious.
>
>  If you follow the thread you can see this effect with a sample image
>  (fluorescentcells), which after you convert it to a 16bit tiff file.
>
>  Thanks,
>
>  Rigo
>
>  On Thu, Apr 10, 2008 at 10:34 AM, Harry Parker <[hidden email]>
>  wrote:
>
>
>
>  > Have you tried deselecting the menu option, Edit->Options->Profile Plot
>  > Options...->Interpolate Line Profiles?
>  >
>  > --
>  > Harry Parker
>  > Senior Systems Engineer
>  > Digital Imaging Systems, Inc.
>  >
>  > ----- Original Message ----
>  > From: Rigo Pantoja <[hidden email]>
>  > To: [hidden email]
>  > Sent: Wednesday, April 9, 2008 2:35:21 PM
>  > Subject: plot profile problems with pixel value
>  >
>  > All,
>  >
>  > The plot profile (Ctrl+K)  is yielding different values for the same
>  > pixel.
>  > I Noticed this when I generated plot profiles for an individual spot along
>  > the x and y axis.   The  peak  pixel  value was different for the comon
>  > interesection.  Also, if you generate a various plot profiles for with
>  > increasing lengths, the peak pixel value changes.  Can this bug be fixed?
>  >
>  > Thanks,
>  >
>  > Rigo
>  >
>  >
>  >
>  >
>  > __________________________________________________
>  > Do You Yahoo!?
>  > Tired of spam?  Yahoo! Mail has the best spam protection around
>  > http://mail.yahoo.com
>  >
>

[Rigo Pantoja]

Jonathan,

The problem is fixed in version 1.40e.  Thanks,

Rigo

On Thu, Apr 10, 2008 at 1:51 PM, Jonathan Hilmer <[hidden email]> wrote:

> I think the problem you're seeing arises from the spatial definitions
> and representations of each pixel.  Rather than go through a lengthy
> explanation, try using the point selection tool and Measurements
> (which will give the same results as Plot Profile and is faster to
> check) when zoomed in.  You'll see the effect causing your results,
> which actually arises from a very methodical way of processing the
> pixelated data.
>
> The slight difference I see between the point selection tool and line
> selections is that the line selections seems to go to the nearest
> pixel "corner" for a measurement while the point selection is always
> to the upper-left.
>
> Jonathan
>
>
> On Thu, Apr 10, 2008 at 2:14 PM, Rigo Pantoja <[hidden email]>
> wrote:
> > Hi Harry,
> >
> >  Wayne recommened your suggestion.  It did not work.
> >
> >  Basically, when you zoom in and draw a line across a set of linear
> pixels,
> >  you get a variable reading of the pixel value if the line does not
> cross the
> >  pixel in the exact center.  If your pixels values are high you might
> not
> >  notice.  However, if you are analyzing single-molecues - where every
> count
> >  matters - this becomes obvious.
> >
> >  If you follow the thread you can see this effect with a sample image
> >  (fluorescentcells), which after you convert it to a 16bit tiff file.
> >
> >  Thanks,
> >
> >  Rigo
> >
> >  On Thu, Apr 10, 2008 at 10:34 AM, Harry Parker <[hidden email]>
> >  wrote:
> >
> >
> >
> >  > Have you tried deselecting the menu option, Edit->Options->Profile
> Plot
> >  > Options...->Interpolate Line Profiles?
> >  >
> >  > --
> >  > Harry Parker
> >  > Senior Systems Engineer
> >  > Digital Imaging Systems, Inc.
> >  >
> >  > ----- Original Message ----
> >  > From: Rigo Pantoja <[hidden email]>
> >  > To: [hidden email]
> >  > Sent: Wednesday, April 9, 2008 2:35:21 PM
> >  > Subject: plot profile problems with pixel value
> >  >
> >  > All,
> >  >
> >  > The plot profile (Ctrl+K)  is yielding different values for the same
> >  > pixel.
> >  > I Noticed this when I generated plot profiles for an individual spot
> along
> >  > the x and y axis.   The  peak  pixel  value was different for the
> comon
> >  > interesection.  Also, if you generate a various plot profiles for
> with
> >  > increasing lengths, the peak pixel value changes.  Can this bug be
> fixed?
> >  >
> >  > Thanks,
> >  >
> >  > Rigo
> >  >
> >  >
> >  >
> >  >
> >  > __________________________________________________
> >  > Do You Yahoo!?
> >  > Tired of spam?  Yahoo! Mail has the best spam protection around
> >  > http://mail.yahoo.com
> >  >
> >
>