Prev: Standalone Parallel Computing
Next: Problem with Move Camera Forward/Back using Camera Toolbar
From: Steven Lord on 17 May 2010 10:38

"Samiov " <Samyw69(a)yahoo.fr> wrote in message
news:hso55l$1ib$1(a)fred.mathworks.com...
> ImageAnalyst <imageanalyst(a)mailinator.com> wrote in message
> <b80c94af-8344-4af4-850b-eaea76c19f36(a)h9g2000yqm.googlegroups.com>...
>> No, the screen has nothing to do with it. Your image could take up
>> the same, say, 1024 pixels across your screen but if it's an image of
>> a cell in a microscope or a galaxy from a telescope they'll have
>> different real world sizes. You need some calibration target in the
>> plane of the scene. This can be the image or a ruler, or a micron bar
>> that the microscope puts on there, or a known distance or size of some
>> known object in your scene such as the angular subtense between two
>> stars. What do you have in your scene that has a known size?
> __________________________________________________________________________
> But If I know the zoom of my image...I used a microscope cam�ra which
> enlarge my image 50 times...does it help to know the size of a pixel ? or
> not?

Suppose I showed you just the first picture on this Wikipedia page -- no
caption, nothing else.

http://en.wikipedia.org/wiki/Eiffel_Tower

How tall is the object in the picture? Is it a picture of the real Eiffel
Tower (324.00 meters tall) or is it simply a picture of an extremely
detailed scale model built for, say, a model railroad layout of Paris, that
is only 0.5 meters tall?

http://en.wikipedia.org/wiki/Model_railroad_layout

Since there's no indication of the scale, there's no way to tell.

--
Steve Lord
slord(a)mathworks.com
comp.soft-sys.matlab (CSSM) FAQ: http://matlabwiki.mathworks.com/MATLAB_FAQ


From: Samiov on 18 May 2010 05:54
Thanks guys, I understood...It must be at the moment of taking the pictures..
First  |  Prev  | 
Pages: 1 2
Prev: Standalone Parallel Computing
Next: Problem with Move Camera Forward/Back using Camera Toolbar