Measurement method of three-dimensional profiles and reconstruction system thereof using subpixel localization with color gratings and picture-in-picture switching on single display

The present invention is a measurement method of three-dimensional profiles and a reconstruction system thereof using subpixel localization with color gratings and picture-in-picture switching on a single display, wherein the measurement method includes: 1. Preparation step; 2. Projection step; 3. Image extraction step; 4. Image fine-tuning step; 5. Image processing step; and 6. Reconstruction step. The system includes: a projection apparatus, emitting a grating towards a workpiece under measurement, and forming a grating image on the workpiece under measurement, the contrast values of the plurality of grating stripes of the grating image being identical; a central processing unit, using the grating image and picture-in-picture of a display thereof to fine tune and reconstruct three-dimensional profiles of the workpiece under measurement. Thereby, the grating stripes have equal contrast for easier identification; the display has switchable picture-in-picture; and an adjustment module can adjust the grating.