This work proposes a novel non-destructive, vision-based measurement strategy to identify and quantify mechanical deformations between rigid blocks. First the possible motions between two rigid blocks were identified and measured, under the application of a perpendicular, parallel and symmetrical 4x4 point grid around the masonry joint line. Repeated calculations of lengths, dot products, and right triangles improved the precision of measurements through redundancy. Then, this method was verified via photographic images with defined deformation and 2D holography, showing good adaptability and precision. Finally, this strategy was performed to a video recording of an arch under tilting test until failure. With the dimensions of the points grid being the only known parameter, the mechanical joint, the type of rigid block motion, the failure point and the rotation angle were successfully determined
