Resolving Distance Measurement Ambiguities Using Coded-Modulation Phase Image Frames

摘要

Distance ambiguities arising from indirect time-of-flight (ToF) measurements are resolved by using additional information from two or more coded-modulation measurements. An indirect ToF measurement is performed for a pixel of an image processor, to obtain a value indicative of an apparent distance to an imaged object or scene. First and second coded-modulation measurements are also performed, using respective combination of modulation code and reference signals, such that correlation peaks corresponding to these measurements overlap and cover respective first and second adjoining ranges of distances to imaged objects. First and second mask values are determined from the correlation values obtained from the coded-modulation measurements and are used to determine whether the value indicating the apparent distance indicates an actual distance within the first range of distances or within the second range of distances.