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How to convert pixels to mm?

lyndalouis Posted messages 18 Status Membre -  
Pierrecastor Posted messages 10830 Registration date   Status Modérateur Last intervention   -
Hello,
I am working on an image correlation software, it gives the deformation in pixels.
Please, how can I convert it to mm?
Thank you.

2 réponses

Réponse 1 / 2
Pierrecastor Posted messages 10830 Registration date   Status Modérateur Last intervention   4 215
 
Hello

To calculate that, you also need to know the resolution of the image.

--
Light a fire for someone and they'll be warm for the rest of the day. Set a man on fire and he'll be warm for the rest of his life.
-Terry Pratchett-
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Réponse 2 / 2
lyndalouis Posted messages 18 Status Membre
 
Is it the parameters of these little squares that we call resolution?
Because I am working with a grid that I draw and the step of this grid is 10*10 pixels
Does this mean that my resolution is 100 pixels?
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Pierrecastor Posted messages 10830 Registration date   Status Modérateur Last intervention   4 215
 
Resolution is the number of pixels per square inch or per square centimeter.

It is often given in dpi.
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kaumune Posted messages 22694 Registration date   Status Contributeur Last intervention   5 156
 
Hi

Not per square inch or cm squared, but per inch or cm straight up


DPI = dots per inch ... dots per inch

Be careful, moreover, not to confuse pixel and point

https://blog.rom1v.com/2009/03/resolution-pixels-points-dpi-un-casse-tete-insoluble/


https://en.wikipedia.org/wiki/Pixel
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Pierrecastor Posted messages 10830 Registration date   Status Modérateur Last intervention   4 215
 
Oops, the idiot.

Yes, it's indeed based on distance per unit.

I don't know what was going through my mind.
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