A stereo imaging system includes an optical assembly and a computational pixel imager (CPI) having a plurality of pixels. Each pixel includes a light sensor and counters that convert a photocurrent from the light sensor to a digital signal. The optical assembly, which directs light from a light field to the CPI, includes an optical field combiner and first and second primary lens assemblies, which are configured to receive first and second portions of the light from the light field, respectively, and to direct the first and second portions of the light to the optical field combiner. The optical field combiner includes a modulator configured to modulate the first and second portions of the light and to direct modulated first and second portions of the light onto the CPI. The counters are configured to perform digital signal processing on the digital signal.

A computational pixel imaging device can include multiple digitizing counters per pixel that can be used to execute simultaneous signal-processing threads on acquired image data. The imaging device can also include infinite dynamic range sensing and perform signal down-sampling.

Methods and apparatus to count people are disclosed. Example apparatus disclosed herein include means for discarding existing characteristic datasets from a list; means for populating the list with first characteristic datasets obtained from a first plurality of images representative of an environment during a first period of time of a media presentation; means for limiting a number of the first characteristic datasets stored in the list for a first location represented in the first plurality of images; and means for comparing the first characteristic datasets to each other to determine a first number of unique faces in the environment during the first period of time, wherein the means for discarding is to delete the first characteristic datasets from the list, and the means for populating is to re-populate the list with second characteristic datasets obtained from a second plurality of images representative of the environment.

Methods and apparatus to count people are disclosed. Example apparatus disclosed herein include means for discarding existing characteristic datasets from a list; means for populating the list with first characteristic datasets obtained from a first plurality of images representative of an environment during a first period of time of a media presentation; means for limiting a number of the first characteristic datasets stored in the list for a first location represented in the first plurality of images; and means for comparing the first characteristic datasets to each other to determine a first number of unique faces in the environment during the first period of time, wherein the means for discarding is to delete the first characteristic datasets from the list, and the means for populating is to re-populate the list with second characteristic datasets obtained from a second plurality of images representative of the environment.

Various embodiments disclosed herein describe a divided-aperture infrared spectral imaging (DAISI) system that is adapted to acquire multiple IR images of a scene with a single-shot (also referred to as a snapshot). The plurality of acquired images having different wavelength compositions that are obtained generally simultaneously. The system includes at least two optical channels that are spatially and spectrally different from one another. Each of the at least two optical channels are configured to transfer IR radiation incident on the optical system towards an optical FPA unit comprising at least two detector arrays disposed in the focal plane of two corresponding focusing lenses. The system further comprises at least one temperature reference source or surface that is used to dynamically calibrate the two detector arrays and compensate for a temperature difference between the two detector arrays.

Various embodiments disclosed herein describe a divided-aperture infrared spectral imaging (DAISI) system that is adapted to acquire multiple IR images of a scene with a single-shot (also referred to as a snapshot). The plurality of acquired images having different wavelength compositions that are obtained generally simultaneously. The system includes at least two optical channels that are spatially and spectrally different from one another. Each of the at least two optical channels are configured to transfer IR radiation incident on the optical system towards an optical FPA unit comprising at least two detector arrays disposed in the focal plane of two corresponding focusing lenses. The system further comprises at least one temperature reference source or surface that is used to dynamically calibrate the two detector arrays and compensate for a temperature difference between the two detector arrays.

A system for use in identifying a user includes a portable emitter transported with the user. The emitter includes a quantum cascade laser configured to emit a thermal beam identifying a location of the user in response to a command, the thermal beam having a wavelength between approximately 2 m and approximately 30 m.

A system for use in identifying a user includes a portable emitter transported with the user. The emitter includes a quantum cascade laser configured to emit a thermal beam identifying a location of the user in response to a command, the thermal beam having a wavelength between approximately 2 m and approximately 30 m.

Methods and apparatus to count people are disclosed. Example apparatus disclosed herein include means for discarding existing characteristic datasets from a list; means for populating the list with first characteristic datasets obtained from a first plurality of images representative of an environment during a first period of time of a media presentation; means for limiting a number of the first characteristic datasets stored in the list for a first location represented in the first plurality of images; and means for comparing the first characteristic datasets to each other to determine a first number of unique faces in the environment during the first period of time, wherein the means for discarding is to delete the first characteristic datasets from the list, and the means for populating is to re-populate the list with second characteristic datasets obtained from a second plurality of images representative of the environment.

Methods and apparatus to count people are disclosed. Example apparatus disclosed herein include means for discarding existing characteristic datasets from a list; means for populating the list with first characteristic datasets obtained from a first plurality of images representative of an environment during a first period of time of a media presentation; means for limiting a number of the first characteristic datasets stored in the list for a first location represented in the first plurality of images; and means for comparing the first characteristic datasets to each other to determine a first number of unique faces in the environment during the first period of time, wherein the means for discarding is to delete the first characteristic datasets from the list, and the means for populating is to re-populate the list with second characteristic datasets obtained from a second plurality of images representative of the environment.