The phrase "pixel value mm2 new" likely refers to a feature or calculation used in digital imaging, medical diagnostics, or design software to translate digital pixel data into real-world physical measurements m m squared

Example:

Whether you are diagnosing a tumor, inspecting a circuit board, or mapping a forest fire, calculating this new metric will save you storage, processing time, and most importantly, prevent you from confusing noise for detail.

If you have PPI (pixels per inch):
1 inch = 25.4 mm, so pixel pitch p (mm) = 25.4 / PPI
Area per pixel (mm²) = (25.4 / PPI)^2