*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

Precisely.

                            Guy

-----Original Message-----
From: Confocal Microscopy List [mailto:[log in to unmask]] On Behalf Of Mark Cannell
Sent: Sunday, 15 April 2012 9:17 PM
To: [log in to unmask]
Subject: Re: Nyquist and Image size

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

Hi Guy

Thanks a lot! You have got the wrong end of the stick. I am not talking about image reconstruction but displaying raw pixel data...

Cheers


On 15/04/2012, at 11:33 AM, Guy Cox wrote:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
> 
> OK, I think I know Mark well enough that I can just say bollocks.
> 
> Representing a sample as a square (ie presenting a sine wave as a square wave) is introducing a whole series of (every alternate) higher harmonics which contribute absolutely NOTHING to the image.   This is really fundamental to understanding digital imaging.
> 
>                                                                               
> Guy
> 
> -----Original Message-----
> From: Confocal Microscopy List 
> [mailto:[log in to unmask]] On Behalf Of Mark Cannell
> Sent: Sunday, 15 April 2012 11:35 AM
> To: [log in to unmask]
> Subject: Re: Nyquist and Image size
> 
> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
> 
> Hi Johannes
> 
> Sorry I disagree. You are recording an image. The point is that the pixels integrate over their entire face which is square so that this may be represented by square pixels perfectly faithfully. I have no idea what your analogy to the images of the sun through leaves has to do with this, the leavers are apertures. 
> 
> Cheers Mark
> 
> 
> On 14/04/2012, at 6:43 PM, Johannes Schindelin wrote:
> 
>> Hi Mark,
>> 
>> On Sat, 14 Apr 2012, Mark Cannell wrote:
>> 
>>> That's a nice 'rant' but it does of course ignore the fact that many 
>>> cameras have square pixels...
>> 
>> But it is not the square detectors of the camera you are recording. 
>> There is a whole optical path up until then.
>> 
>> Pixels are not the physical dimension of the detector, they are an 
>> abstract construct to describe what the number (or numbers) attached 
>> to it
>> -- the pixel value -- actually mean.
>> 
>> To say that pixels are square because the CCD is organized in a grid 
>> is like saying that the spots the sun is leaving in a forest of trees 
>> are as oddly shaped as the holes made by leaves through which the 
>> sun's rays reach the soil.
>> 
>> Ciao,
>> Johannes