3D sensing depth camera

A system for 3D depth sensing, comprising:

• a light source that produces a light across frequencies from a first frequency to a last frequency;
• a beam splitter system that is disposed to split the light from the light source into at least a reference beam and a sample beam;
• a sample arm structured to receive the sample beam from the beam splitter system and return a return sample beam, the sample arm comprising a scanner for beam scanning in a first axis and a diffractive optical element for spectrally encoded scanning along a second axis;
• a detector that is disposed to collect an interference signal between the reference beam and the return sample beam returning from the sample arm, the interference signal forming an interferogram, wherein for each frequency sweep across the frequencies from the first frequency to the last frequency, the interferogram comprises depth information at a different position along the second axis;
• and
• a processing system coupled to the detector, the processing system comprising a hardware processor and a memory storing instructions that when executed by the hardware processor direct the processing system to:
• receive the interferogram of each frequency sweep across the frequencies from the first frequency to the last frequency from the detector;
• for each interferogram, apply a windowed spectral estimator at a particular spectral window size with zero-padding and according to a specified lateral sampling approach, wherein the spectral window size is based on a lateral resolution of the system such that if a point spread function of two adjacent wavelengths are unresolvable, detected signals from the two adjacent wavelengths are treated as arising from a same position and are analyzed within a same spectral window, by:
• sampling the interferogram according to the specified lateral sampling approach;
• and
• for each spectral window sample of the interferogram, applying zero-padding to a particular number of samples and applying a spectral estimator to the zero-padded spectral window sample to generate a signal for a pixel;
• performing peak localization analysis on the signal to identify a dominant peak;
• and if the dominant peak is identified, assigning a depth value according to a corresponding depth position of the dominant peak for the pixel, otherwise, assigning the pixel as a background;
• and
• provide a depth map of the pixels comprising the assigned depth values.