An Image Sensor for Sheet-of-Light Range Imaging

Range image acquisition can be made in many different ways. In this paper the range data are acquired by using a sheet-of-light to illuminate the scene 121, [31. Our image sensor design incorporates the concept of Near-Sensor Image Processing (NSIP) where the individual sensor operation is an integrated part of the signal processing algorithm [I]. This architecture can provide range images with very high frame rates. The limit is set by the inteeration time in the sensor. and we believe t i a t a full range image can be captured in 6.5 ms. The NSIP design is automatically adaptive to different light intensities since the utilized integration time for each cell depends on the incoming light. There is no transfer of analog data; each sensor cell output is binary and thus there is no signal degradation in the image readout. Auxilary logic is incorporated to automatically obtain sub-pixel accuracy and an error indicating bit to indicate low confidence range values. Concurrent with the range image, the chip can also produce a grey level reflectance image. changes so that a full triangulation computation has to be made to obtain the distance to the objects in the image. In any case, for each illumination position (and sensor integration) as a first computational step the output from the 2D image sensor should be reduced to a ID-array of offset values.