Can I create images with accurate size in mm ?

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MaryD 2024-1-17

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回答： Muskan 2024-1-23

I need to create phantom data- for example white sqare on black background with known size and position in milimiters. Is it possible to create something like that in matlab? Or does matlab perform with pixels size only ?

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DGM 2024-1-17

编辑：DGM 2024-1-17

Raster image data is in pixels only. Any information about physical size is either implied by the relative scale of reference features within the physical image, or by metadata stored in the file header, though the vast majority of default-generated resolution metadata in non-technical images is either contextually meaningless or wrong. If all you have is a white square on a black background, then there is no implied scale. If you want to include that information, it depends how you want to do it and what file format you're using.

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Answer 1

Image Analyst 2024-1-23

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spatial_calibration_demo.m

Using a known distance in real world units and a measured pixel distance in your image, you can create a spatial calibration factor "mmPerPixel" that you can multiply your pixel measurements by. See my attached demo for how to do that.

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Answer 2

Muskan 2024-1-23

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Hi Mary,

As per my understanding, in MATLAB, image representation is inherently based on pixel units. As such, to facilitate the use of different units such as millimeters (mm), one would need to implement a custom conversion routine. Currently, MathWorks does not provide a built-in function specifically for this purpose.