NOVELTY - The system has an illuminating unit (12) with a coherent light source (12A) and a generator (12B) such as ground glass, of a constant random speckle pattern accommodated in the optical path of illuminating light. The illuminating unit projects a random speckle pattern onto an object (13). An imaging device (14) has a light detector e.g. charge coupled device (14A), and equipped with an imaging lens arrangement (14B). The imaging device detects a light response of an illuminated region and generates an image data, which is indicative of the object with the projected speckles pattern.    USE - Used for an object reconstruction (claimed), and to provide data input to a man machine interface for e.g. gaming and fitness, a camera in a cellular device and to provide three dimensional capability for bio-medical application such as endoscopy, range estimation between a vehicle and proximity alarm or intrusion alarm.    ADVANTAGE - The imaging device detects a light response of an illuminated region and generates an image data, which is indicative of the object with the projected speckles pattern, thus identifying a shift of the pattern in the image of the object relative to a reference image of the pattern, reference image of the pattern, and hence enabling real-time reconstruction of a three-dimensional map of the object. The configuration of the system is simple and allows for acquiring only a single image of the object with a projected random pattern and for utilizing a simple image matching algorithm, thus reducing the computational complexity of image processing to reconstruct the three dimensional map of the object.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for the following:    (1) a projection module for use in a system for object reconstruction, comprising a coherent light source    (2) an optical mapping method.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic illustration of an optical system.    Distances (d, L)    Axis (Z)    Illuminating unit (12)    Generator (12B)    Object (13)    Imaging device (14)    Imaging lens arrangement (14B)