Techniques for reducing a likelihood of detection of an imaging system by another imaging system are provided. For example, the techniques may include controlling read-out such that the timings between frames of an image are non-uniform. For example, a processor may be configured to generate a plurality of frame synchronization signals from a main clock and transmit the plurality of frame synchronization signals to readout circuitry. Each frame synchronization signal is an instruction to start the biasing and reading for a respective frame. The plurality of frame synchronization signals may be generated such that a timing between pulse biasing the same thermal sensor is not uniform. The techniques may also include controlling the read-out such that the timings between lines within a frame are non-uniform which also results in the timing between pulse biasing of the same thermal sensor not being uniform.

Techniques are disclosed for imager health monitoring systems and methods. In one example, a method includes determining a characteristic of an active unit cell of a focal plane array (FPA) and/or a reference unit cell of the FPA. The active unit cell includes a detector selectively shielded from an incident scene. The reference unit cell includes a reference detector shielded from the incident scene. The method further includes determining a state of the FPA based at least in part on the characteristic. The method further includes transmitting an indication of the state of the FPA to selectively cause adjustment of the FPA Related devices and systems are also provided.

Thermal cameras, particularly less elaborate inexpensive designs, may deliver high temperature resolution at the expense of less clear displayed images. For many low visibility uses, such as firefighting, it may be advantageous to sacrifice some temperature detail for clarity and object recognition. Without sacrificing the actual detailed temperature information available in a captured scene, it may be beneficial to apply filters in series to raw image data that reduce visible noise and build back in feature contrast for the purposes of providing a user a displayed image that permits ease of object recognition, while still providing the raw data to a thermography module to maintain high resolution of temperature information if desired. In addition, more efficient and useful edge highlighting techniques are disclosed. For very low contrast scenes, such as smoky rooms and the like, other specific filters and equalization methods may be applied.

Thermal cameras, particularly less elaborate inexpensive designs, may deliver high temperature resolution at the expense of less clear displayed images. For many low visibility uses, such as firefighting, it may be advantageous to sacrifice some temperature detail for clarity and object recognition. Without sacrificing the actual detailed temperature information available in a captured scene, it may be beneficial to apply filters in series to raw image data that reduce visible noise and build back in feature contrast for the purposes of providing a user a displayed image that permits ease of object recognition, while still providing the raw data to a thermography module to maintain high resolution of temperature information if desired. In addition, more efficient and useful edge highlighting techniques are disclosed. For very low contrast scenes, such as smoky rooms and the like, other specific filters and equalization methods may be applied.

A computer-implemented method for displaying thermal images by a thermal imager device is provided. The method includes displaying, by a user interface of a computing device, a plurality of thermal images corresponding to a respective plurality of objects in a scene captured by the thermal imager device. The plurality of thermal images are displayed by a first representation scheme based on a first thermal scale comprising a first range of temperature values corresponding to the plurality of objects. The method includes receiving, by the computing device, a user selection of a subplurality of the plurality of thermal images. And the method includes, responsive to the user selection, displaying, by the user interface, the subplurality of the plurality of thermal images by a second representation scheme based on a second thermal scale comprising a second range of temperature values corresponding to a respective subplurality of the plurality of objects.

A computer-implemented method for displaying thermal images by a thermal imager device is provided. The method includes displaying, by a user interface of a computing device, a plurality of thermal images corresponding to a respective plurality of objects in a scene captured by the thermal imager device. The plurality of thermal images are displayed by a first representation scheme based on a first thermal scale comprising a first range of temperature values corresponding to the plurality of objects. The method includes receiving, by the computing device, a user selection of a subplurality of the plurality of thermal images. And the method includes, responsive to the user selection, displaying, by the user interface, the subplurality of the plurality of thermal images by a second representation scheme based on a second thermal scale comprising a second range of temperature values corresponding to a respective subplurality of the plurality of objects.

A photodetector interface circuit is described, residing partially or fully within a unit cell per pixel of an FPA. The interface circuit uses an innovative approach to providing pixel level digitization for full frame integration times while maintaining the ability to use integration capacitors of practical sizes. The technique uses successive charge subtraction, removing charge from an integration capacitor successively, triggered by the charge increasing sufficiently to charge the integrator to a reference level, thereby triggering both charge removal and incrementing a count, until all of the current flowing in the photodetector has been accounted for and the count represents the digitization of the photodetector signal. Various options on how to arrange the digitization elements are also disclosed.

Depth sensors comprising a focal plane array with photosites (PSs) directed in different directions, each PS operable to detect light arriving from an instantaneous field of view (IFOV) of the PS, a readout-set of readout circuitries (ROCs), each ROC coupled to readout-group PSs by multiple switches and operable to output an electric signal indicative of an amount of light impinging on the readout-group PSs when the read-out group is connected to the respective ROC via at least one of the switches, a controller operable to change switching states of the switches, such that at different times different ROCs of the readout-set are coupled to the readout-group and are exposed to reflections from different distances, and a processor operable to obtain the electric signals from the readout-set indicative of detected levels of reflected light collected from the IFOVs of the readout-group and to determine depth information for an object.

Depth sensors comprising a focal plane array with photosites (PSs) directed in different directions, each PS operable to detect light arriving from an instantaneous field of view (IFOV) of the PS, a readout-set of readout circuitries (ROCs), each ROC coupled to readout-group PSs by multiple switches and operable to output an electric signal indicative of an amount of light impinging on the readout-group PSs when the read-out group is connected to the respective ROC via at least one of the switches, a controller operable to change switching states of the switches, such that at different times different ROCs of the readout-set are coupled to the readout-group and are exposed to reflections from different distances, and a processor operable to obtain the electric signals from the readout-set indicative of detected levels of reflected light collected from the IFOVs of the readout-group and to determine depth information for an object.

A thermal image sensor includes a substrate; a composite layer including an absorption layer and a sensor array layer provided below the absorption layer, the sensor array layer including a plurality of temperature sensing cells, the composite layer having a pattern formed therein, and the pattern including at least one hole penetrating through the absorption layer; and a support separating the substrate from the composite layer.