Electronic device with an upscaling processor and associated method

A method of upscaling depth maps produced by a single-photon avalanche diode (SPAD) array using an upscaling processor, the method comprising:

• receiving, by the upscaling processor, a first depth map having a first resolution and a signal count map having a second resolution higher than the first resolution, the first depth map comprising a plurality of distance observations to an object, the signal count map comprising a plurality of intensity observation sets of the object, each of the plurality of intensity observation sets and a respective distance observation providing different information for a same region of an object measured by the SPAD array, each of the plurality of intensity observation sets comprising a plurality of intensity observations measuring reflected intensities for a region of the object, each respective distance observation measuring a distance between the SPAD array and the region of the object;
• identifying, by the upscaling processor, background macropixels in each of the plurality of intensity observation sets;
• identifying, by the upscaling processor, partially covered macropixels in each of the plurality of intensity observation sets;
• calculating, by the upscaling processor, an average intensity observation for each of the plurality of intensity observation sets using values of fully covered macropixels in the each of the plurality of intensity observation sets, wherein the fully covered macropixels are macropixels in each of the plurality of intensity observation sets other than the partially covered macropixels and other than the background macropixels;
• and
• calculating, by the upscaling processor, a second depth map having the second resolution using the first depth map, the signal count map, and the average intensity observation of each of the plurality of intensity observation sets, wherein calculating, by the upscaling processor, the second depth map comprises, for each of the plurality of intensity observation sets:
• calculating a plurality of upscaling factors for the fully covered macropixels;
• and
• calculating upscaled distance values for the fully covered macropixels by multiplying the plurality of upscaling factors with the respective distance observation.

An electronic device comprising:

• an imager comprising a single-photon avalanche diode (SPAD) array, wherein the imager is configured to
• generate a first depth map having a first resolution, wherein the first depth map has a first number of distance observations to an object, and
• generate a signal count map having a second resolution greater than the first resolution, wherein the signal count map has the first number of intensity observation sets of the object, wherein each of the first number of intensity observation sets has a plurality of intensity observations, wherein each of the plurality of intensity observation set and a corresponding distance observation provide measurements of different properties for a same region of the object;
• an upscaling processor coupled to the imager;
• and
• a non-transitory computer readable storage medium storing programming for execution by the upscaling processors, the programming including instructions to:
• identify, by the upscaling processor, fully covered macropixels in each of the first number of intensity observation sets;
• calculate, by the upscaling processor, an average intensity observation for each of the first number of intensity observation sets using values of the fully covered macropixels in the each of the first number of intensity observation sets;
• and
• calculate, by the upscaling processor, a second depth map having the second resolution using the first depth map, the average intensity observation of each of the first number of intensity observation sets, and the signal count map,
• wherein the upscaling processor is configured to calculate the second depth map by:
• calculating an upscaling factor for each of the fully covered macropixels using a value of the each of the fully covered macropixels and a respective average intensity observation, and
• calculating an upscaled distance value for the each of the fully covered macropixels using the upscaling factor and a respective distance observation.