3d+ imaging systems with on-chip neighbor-in-time analog sub-pixel processing and single-pixel motion determination

Abstract

Various embodiments of a 3D+ imaging system include imaging systems with on-chip neighbor-in-time analog sub-pixel processing and single-pixel motion determination. In embodiments, range gating imaging techniques are used to generate a composite image depth map of a scene based on analog sub-pixel processing are implemented. In embodiments, high-intensity rate of change of neighboring pixels techniques are used to generate a composite image two-axis motion map of a scene at a pixel level. In embodiments, an analog pixel circuit is disclosed for use with an array of photodetectors for a sub-frame composite imaging system. In embodiments, an extended-dynamic-range imaging technique is used in imaging to reproduce a greater dynamic range of luminosity.

1 - 11 . (canceled) 
     
     
         12 . An imaging system configured to generate a composite image two-axis motion map of a scene at a pixel level, the imaging system comprising:
 at least one emitter configured to emit an active light pulse toward the scene;   an array of detectors configured to receive light that includes some of the active light pulse reflected from the scene for a field of view that includes at least a portion of the scene, each detector in the array of detectors configured to produce a linearized intensity response to a number of incident photons of light;   control circuitry operably coupled to the at least one emitter and the array of detectors and configured to store a set of at least three successive sub-frames of intensity data as sub-frame pixels in one or more sub-frame buffers, wherein each sub-frame pixel has a timing relationship of an emitter/detector cycle for that sub-frame pixel and each set of sub-frame pixels associated with a unique one of an array of pixels based on a row and a column corresponding to the array of detectors; and   a processing system operably coupled to the control circuitry and the one or more sub-frame buffers to generate the composite image two-axis motion map of the scene, the processing system configured to:
 analyze at least three successive sub-frame pixels to determine for each pixel in the array of pixels a black point due to ambient light in the scene and a white point due to the active light pulse reflected from the scene for at least the first sub-frame pixel and the last sub-frame pixel for the set of sub-frame pixels for that pixel; 
 generate a horizontal axis motion value for each pixel relative to a row in the pixel array based on a high-intensity rate of change between that pixel and at least one neighbor pixel in the row; and 
 generate a vertical axis motion value for each pixel relative to a column in the pixel array based on a high-intensity rate of change between that pixel and at least one neighbor pixel in the column. 
   
     
     
         13 . The imaging system of  claim 12  wherein the processing system determines the high-intensity rate of change by evaluating a sub-frame pixel at which a slope of the white point crosses over a trailing edge of the black point for a neighbor pixel in a pixel triplet for a given row or column of the pixel array that has a slope that is non-zero. 
     
     
         14 . The imaging system of  claim 12  wherein a duration of a capture cycle is constant for the at least three successive sub-frame pixels, and an intensity and a duration of the active light pulse emitted during the capture cycle is the same for the first sub-frame pixel and the last sub-frame pixel, but the intensity and the duration of the active light pulse is different for at least one sub-frame pixel between the first sub-frame pixel and the last sub-frame pixel. 
     
     
         15 . The imaging system of  claim 12  wherein a duration of a capture is the same for the first sub-frame pixel and the last sub-frame pixel, but the duration of a capture is shorter for at least one sub-frame pixel between the first sub-frame pixel and the last sub-frame pixel. 
     
     
         16 . The imaging system of  claim 12  wherein the imaging system is mounted in a vehicle capable of moving at speeds of more than 50 km/hour and all of the three or more sub-frame pixels for each pixel are stored within an imaging window less than 250 μSec. 
     
     
         17 . The imaging system of  claim 12  wherein the imaging system is mounted in a handheld device and the three or more sub-frame pixels for each pixel are stored within an imaging window of less than 2500 μSec. 
     
     
         18 . The imaging system of  claim 12  wherein the processing system, the array of detectors, the control circuitry, and the processing system are integrated on a single chip. 
     
     
         19 . The imaging system of  claim 12  wherein the processing system, the array of detectors, and the control circuitry are integrated on a single chip and the processing system is external to the single chip. 
     
     
         20 . The imaging system of  claim 12  wherein the active light pulse in a given emitter/detector cycle for a given pixel comprises:
 a number of pulses selected from the set consisting of a single pulse per pixel, a sequence of multiple pulses per pixel, a single pulse per sub-pixel, or multiple pulses per sub-pixel, and 
 a frequency selected from the set consisting of a single frequency range or multiple frequency ranges. 
 
     
     
         21 - 35 . (canceled) 
     
     
         36 . The imaging system of  claim 12  wherein the array of detectors is configured to accumulate light based on a single accumulation for the timing relationship of the emitter/detector cycle that is unique for each sub-pixel. 
     
     
         37 . The imaging system of  claim 12  wherein the array of detectors is configured to accumulate light based on a plurality of accumulations for the timing relationship of the emitter/detector cycle that is the same for each sub-pixel. 
     
     
         38 . An imaging system configured to generate a composite image three-axis motion map of a scene at a pixel level, the imaging system comprising:
 at least one emitter configured to emit an active light pulse toward the scene;   an array of detectors configured to receive light that includes some of the active light pulse reflected from the scene for a field of view that includes at least a portion of the scene, each detector in the array of detectors configured to produce a linearized intensity response to a number of incident photons of light;   control circuitry operably coupled to the at least one emitter and the array of detectors and configured to store at least six successive sub-frames of intensity data as sub-frame pixels in one or more sub-frame buffers, wherein each sub-frame pixel has a timing relationship of an emitter/detector cycle for that sub-frame pixel and each set of sub-frame pixels associated with a unique one of an array of pixels based on a row and a column corresponding to the array of detectors with at least three sub-frames dedicated to two-axis motion, and at least three sub-frames dedicated to depth map computation; and   a processing system operably coupled to the control circuitry and the one or more sub-frame buffers to generate three-axis motion for pixels of the scene, the processing system configured to:
 analyze the at least three successive sub-frame pixels to determine for a pixel associated with the sub-frame pixels a black point, a white point, and the sub-frame pixel at which the white point occurs; 
 determine a distance for each pixel based on the sub-frame pixel at which the white point occurs; 
 analyze at least three successive sub-frame pixels to determine for each pixel in the array of pixels a black point due to ambient light in the scene and a white point due to the active light pulse reflected from the scene for at least the first sub-frame pixel and the last sub-frame pixel for the set of sub-frame pixels for that pixel; 
 generate a horizontal axis motion value for each pixel relative to a row in the pixel array based on a high-intensity rate of change between that pixel and at least one neighbor pixel in the row; and 
 generate a vertical axis motion value for each pixel relative to a column in the pixel array based on a high-intensity rate of change between that pixel and at least one neighbor pixel in the column. 
   
     
     
         39 . The imaging system of  claim 38  wherein the processing system determines the high-intensity rate of change by evaluating a sub-frame pixel at which a slope of the white point crosses over a trailing edge of the black point for a neighbor pixel in a pixel triplet for a given row or column of the pixel array that has a slope that is non-zero. 
     
     
         40 . The imaging system of  claim 38  wherein a duration of a capture cycle is constant for the at least three successive sub-frame pixels, and an intensity and a duration of the active light pulse emitted during the capture cycle is the same for the first sub-frame pixel and the last sub-frame pixel, but the intensity and the duration of the active light pulse is different for at least one sub-frame pixel between the first sub-frame pixel and the last sub-frame pixel. 
     
     
         41 . The imaging system of  claim 38  wherein a duration of a capture is the same for the first sub-frame pixel and the last sub-frame pixel, but the duration of a capture is shorter for at least one sub-frame pixel between the first sub-frame pixel and the last sub-frame pixel. 
     
     
         42 . The imaging system of  claim 38  wherein the distance represented by each sub-frame pixel is defined by an overlap in a duration of the timing relationship of the emitter/detector cycle for that sub-frame pixel. 
     
     
         43 . The imaging system of  claim 38  wherein the processing system, the array of detectors, the control circuitry, and the processing system are integrated on a single chip. 
     
     
         44 . The imaging system of  claim 38  wherein the active light pulse in a given emitter/detector cycle for a given pixel comprises:
 a number of pulses selected from the set consisting of a single pulse per pixel, a sequence of multiple pulses per pixel, a single pulse per sub-pixel, or multiple pulses per sub-pixel, and 
 a frequency selected from the set consisting of a single frequency range or multiple frequency ranges. 
 
     
     
         45 . The imaging system of  claim 38  wherein the array of detectors is configured to accumulate light based on a single accumulation for the timing relationship of the emitter/detector cycle that is unique for each sub-pixel. 
     
     
         46 . The imaging system of  claim 38  wherein the array of detectors is configured to accumulate light based on a plurality of accumulations for the timing relationship of the emitter/detector cycle that is the same for each sub-pixel.