A Light Modulation/Demodulation Method for Real-Time 3D Imaging

Abstract

This paper describes a novel method for digitizing the 3D shape of an object in real-time, which can be used for capturing live sequence of the 3D shape of moving or deformable objects such as faces. Two DMD (=Digital Micro Mirror) devices are used as high speed switches for modulating and demodulating light rays. One DMD is used to generate rays of light pulses, which are projected onto the object to be measured. Another DMD is used to demodulate the light reflected from the object illuminated by the light pulses into intensity image that describes the disparity. A prototype range finder implementing the proposed method has been built. The experimental results showed that the proposed method works and video sequences of disparity images can be captured in real time.

Exploiting DLP Illumination Dithering for Reconstruction and Photography of High-Speed Scenes

“…In addition, we use no synchronization, and therefore the different profiles are measured across different positions of the color-wheel (since measuring 100 frames at 10kHz requires a 1 100 th second, which is approximately a single color-wheel cycle). This explains the intensity shift in the profiles, which can be addressed by using a projector with the color-wheel removed (as in Section 6, [19], [4]). If those two calibration steps are taken, the profiles in the figure would closely resemble the binary "step function" codes we would expect ( [8]).…”

“…This 'rainbow effect' is well-known to display researchers who wish to remove or reduce it ( [29], [15], [30], [41], [13], [28], [22]). Many researchers even remove the color wheel to increase the projector contrast in their experiments ( [19], [4]). Instead of treating this effect as a problem that must be compensated for, the DLP illumination can be exploited to photograph dynamic scenes.…”

Diseño y desarrollo de un equipo para el control de la calidad en la industria panificadora

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