One embodiment can provide a machine-vision system that includes one or more stereo-vision modules. A respective stereo-vision module can include a structured-light projector, a first camera positioned on a first side of the structured-light projector, and a second camera positioned on a second side of the structured-light projector. The first and second cameras are configured to capture images of an object under illumination by the structured-light projector. The structured-light projector can include a laser-based light source and an optical modulator configured to reduce speckles caused by the laser-based light source.