Convert Lines per millimetre to Pixels per metre

Convert Lines per millimetre (lp/mm) to Pixels per metre (px/m) instantly and accurately.

Conversion Formula

px/m = lp/mm × 1000

About Lines per millimetre

The line pair per millimetre (lp/mm) is the fundamental unit of spatial resolution in classical optics, characterising the resolving power of a lens, film emulsion, sensor, or microscope objective. A resolving power of N lp/mm means adjacent line pairs separated by 1/(2N) mm can be distinguished - derived from the Abbe diffraction limit (Ernst Abbe, 1873) and Rayleigh criterion (Lord Rayleigh, 1879). Film benchmarks at MTF50: Kodak Tri-X 400: 63 lp/mm; Fujifilm Velvia 50: 160 lp/mm; Kodak Technical Pan: 320 lp/mm. Lens benchmarks: Leica APO-Summicron-M 50 mm f/2 ASPH: ≈ 75 lp/mm at centre. CMOS sensor Nyquist frequency: for pixel pitch p mm, f_Nyquist = 1/(2p) lp/mm - a 4.63 µm pixel limits at ≈ 108 lp/mm. As a dimensional unit, 1 lp/mm = 25.4 LPI = 25.4 PPI exactly. 1 lp/mm = 25.4 PPI.

About Pixels per metre

The pixel per metre (px/m) is the SI-coherent form of image resolution. Because 1 inch = 0.0254 m exactly (international inch, 1959), 1 PPI = 1/0.0254 ≈ 39.37 px/m and 1 px/m = 0.0254 PPI. EXIF (IEC 61966-3) stores resolution as pixels per inch (ResolutionUnit = 2) or pixels per centimetre (ResolutionUnit = 3); px/m is used when normalising to SI for scientific or GIS workflows. Satellite remote-sensing GSD is often given in metres per pixel (the inverse); WorldView-3 at 0.31 m/px panchromatic ≈ 3.23 px/m. An A4 document scanned at 300 PPI ≈ 11,811 px/m. 1 px/m = 0.0254 PPI ≈ 0.00254 px/cm.

Quick Reference Table

→ Full Image Resolution Converter