How to SetPixelSize #177
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I am a newbie at Image Analysis. May I ask this silly question? |
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The measurement assumes the pixel size is constant. This is the case in 2D and 3D microscopy, in CAT and MRI scans, and many other imaging modalities. But it is often not the case in photography. To properly measure things in a photograph (the 2D image formed by projecting a 3D scene through a pinhole or lens), you need to determine the distance of the camera to each object (or object part) imaged, thereby partially reconstructing the 3D scene that was photographed. The pixel size for an image is determined by properly calibrating the instrument. This can be as simple as taking an image of a ruler. |
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Got it. Thank you crisluengo. |
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The measurement assumes the pixel size is constant. This is the case in 2D and 3D microscopy, in CAT and MRI scans, and many other imaging modalities. But it is often not the case in photography. To properly measure things in a photograph (the 2D image formed by projecting a 3D scene through a pinhole or lens), you need to determine the distance of the camera to each object (or object part) imaged, thereby partially reconstructing the 3D scene that was photographed.
The pixel size for an image is determined by properly calibrating the instrument. This can be as simple as taking an image of a ruler.