Imaging providing ratio pixel intensity

Patent metadata

Field	Value
Publication number	US-10009549-B2
Application number	US-201515119571-A
Country	US
Kind code	B2
Filing date	Feb 27, 2015
Priority date	Feb 28, 2014
Publication date	Jun 26, 2018
Grant date	Jun 26, 2018

Abstract

Aspects of the present disclosure are directed to apparatuses, systems and methods involving imaging providing pixel intensity ratios using circuitry. According to an example embodiment, an apparatus includes a photosensor array having an array of sensors and a circuitry. Each sensor of the photosensor array provides a signal value for a pixel that is indicative of an intensity of light detected. Further, the circuitry responds to the signal values from a plurality of sensors of the photosensor array, by converting signals indicative of a ratio of pixel intensity values to a digital signal that characterize at least an edge of an object corresponding to or associated with the intensity of the detected light. The circuitry provides digital signals, each indicative of a ratio of pixel intensity values, for respective sensors of the photosensor array.

First claim

What is claimed is:

1. An apparatus comprising:
a photosensor array having an array of sensors, each sensor being configured and arranged to provide a signal value for a pixel that is indicative of an intensity of light detected, with each signal value from the array of sensors including an analog signal indicative of a corresponding pixel intensity value; and
circuitry configured and arranged to
respond to signal values from a plurality of sensors of the photosensor array, by converting signals indicative of a ratio of pixel intensity values to a digital signal that characterizes at least edges of an object corresponding to or associated with the intensity of the detected light, and by providing digital signals, each indicative of a ratio of pixel intensity values for respective sensors of the photosensor array, and
use the digital signals indicative of the ratio of pixel intensity values to form vision feature descriptors based on the edges corresponding with the intensity of light detected.

2. The apparatus of claim 1 , further including a processor circuit separate from or as part of the aforesaid circuitry, configured and arranged to use the digital signals indicative of the ratio of pixel intensity values to assess a correlation of detected objects to heart-related physiological data concurrently captured with the detected light.

3. The apparatus of claim 1 , further including:
a processor circuit, and a communication circuit configured and arranged to provide the digital signals indicative of the ratio of pixel intensity values, to the processor circuit, and wherein the processor circuit is configured and arranged to operate on the digital signals for real-time object detection in a first image-processing mode wherein in response to detecting a trigger event relating to a particular category of object detection, the processor circuit is configured to transition from the first image-processing mode to a second image-processing mode in which the processor circuit receives and operates on more digital signals, corresponding to pixel intensity values, than received and operated on in the first image-processing mode.

4. The apparatus of claim 1 , further including:
a lens configured and arranged with a fixed aperture to pass the light from a scene to the photosensor array; and
the photosensor array, configured and arranged to detect the light from the scene as passed through the fixed aperture and the lens via the array of sensors.

5. The apparatus of claim 1 , wherein the circuitry is configured as an analog pixel intensity ratio to digital converter circuits and configured and arranged to capture time-stamped visual information about scene context.

6. The apparatus of claim 1 , further including a processor circuit configured and arranged to operate on the digital signals for real-time object detection in an augmented reality application.

7. An apparatus comprising:
a photosensor array having an array of sensors, each sensor being configured and arranged to provide a signal value for a pixel that is indicative of an intensity of light detected, with each signal value from the array of sensors including an analog signal indicative of a corresponding pixel intensity value; and
circuitry including:
a first divider circuit configured to change an output of a first sensor of the array of sensors to produce a percentage of the output of the first sensor;
a second divider circuit configured to change an output of a second sensor of the array of sensors to produce a percentage of the output of the second sensor;
a first comparator configured and arranged to compare the percentage of the output of the first sensor to the output of the second sensor; and
a second comparator configured and arranged to compare the percentage of the output of the second sensor to the output of the first sensor.

8. The apparatus of claim 7 , wherein the circuitry further includes:
the first divider circuit includes a first resistor divider network connected to a first input of the comparison circuit and an input of the first comparator configured and arranged to divide the output of the first sensor; and
the second divider circuit includes a second resistor divider network connected to a second input of the comparison circuit and an input of the second comparator configured and arranged to divide the output of the second sensor.

9. The apparatus of claim 7 , wherein the two comparators are further each configured and arranged to output one of two digital signal values for the output of the first sensor and the output of the second sensor.

10. The apparatus of claim 7 , wherein the circuitry further includes:
an analog logarithmic compression circuit connected to the output of the first sensor and an input of the first comparator, and connected to the output of the second sensor and an input of the second comparator, and configured and arranged to output analog signal values of a logarithm of the output of the first sensor and the output of the second sensor.

11. The apparatus of claim 10 , wherein the circuitry is configured and arranged to provide an analog gradient output indicative of a difference between logarithmically compressed signal values from the first and the second sensors corresponding to respective pixels of interest.

12. The apparatus of claim 7 , wherein the sensors of the photosensor array include logarithmic sensors configured and arranged to provide the signal value for the pixels that is logarithmically proportional to the intensity of light detected.

13. The apparatus of claim 7 , wherein the apparatus is configured and arranged to switch from operating in a first imaging mode, the first imaging mode including use of the circuits to convert signals indicative of ratios of pixel intensity values of adjacent sensors of the array of sensors to digital signals, to a second imaging mode in response to detecting an object of interest using the digital signals, the first imaging mode including a lower power and a lower resolution than the second imaging mode; and
operating the apparatus in the second imaging mode to provide digital signals indicative of signal values from the photosensor array to a processor circuit without use of the circuitry.

14. A method for ascertaining characteristics of a scene, comprising:
capturing, using a photosensor array of an apparatus, image data from light rays, the photosensor array having an array of sensors, each sensor being configured and arranged to provide a signal value for a pixel that is indicative of an intensity of light detected, with each signal value from the array of sensors including an analog signal indicative of a corresponding pixel intensity value;
providing, using a readout circuit of the apparatus, signal values from a plurality of sensors of the array of sensors to circuitry of the apparatus;
providing, using the circuitry, an analog signal indicative of a ratio of pixel intensity values from adjacent sensors of the plurality of sensors based on the signals values;
converting, using the circuitry, the analog signal indicative of the ratio of pixel intensity values to digital signals that characterizes at least an edge of an object corresponding to or associated with the intensity of detected light, whereby the circuitry is configured and arranged to provide digital signals, each indicative of a ratio of pixel intensity values, for respective adjacent sensors of the plurality of sensors; and
detecting, using a processor circuit, the object by using the digital signals indicative of the ratio of pixel intensity values, to form vision feature descriptors based on the edges of

Assignees

• Univ Leland Stanford Junior

Inventors

• Omid-Zohoor Alex B

Classifications

• H04N25/57 Primary

  Control of the dynamic range · CPC title

• H04N25/70

  SSIS architectures; Circuits associated therewith · CPC title

• H04N25/42

  by switching between different modes of operation using different resolutions or aspect ratios, e.g. switching between interlaced and non-interlaced mode · CPC title

• H04N23/651 Primary

  for reducing power consumption by affecting camera operations, e.g. sleep mode, hibernation mode or power off of selective parts of the camera · CPC title

• H04N25/76

  Addressed sensors, e.g. MOS or CMOS sensors · CPC title