Device, method and system for blocking unauthorized image acquisition using infrared lights and variable transmissivity screens
A computing device receives calibration images acquired by an image sensor in the presence of infrared light emitted by an infrared light source and/or in the presence of a variable transmissivity screen between the image sensor and items behind the variable transmissivity screen. The computing device analyzes the calibration images to determine whether the image sensor is saturated and/or whether features of the items are discernible in the calibration images. When the image sensor is not saturated and/or the features are discernible, the computing device controls the infrared light source to adjust settings of the infrared light source and/or the variable transmissivity screen example to find settings where the image source is saturated and/or the features are not discernible. Such settings may be used in a block mode to prevent consumer cameras from acquiring images of the items.
1 . A method comprising:
receiving, via a computing device, calibration images acquired by an image sensor in a presence of infrared light emitted by an infrared light source;
analyzing, via the computing device, the calibration images to determine whether the image sensor is saturated;
when the image sensor is not saturated, controlling, via the computing device, the infrared light source to adjust one or more of a direction, frequency of light modulation, and intensity of the infrared light based on the calibration images;
storing unblock mode settings of the infrared light source, where the infrared light does not saturate the image sensor; and
storing block mode settings of the infrared light source, where the infrared light saturates the image sensor.
2 . The method of claim 1 , further comprising:
adjusting, via the computing device, the infrared light source until the image sensor is saturated.
3 . The method of claim 1 , where adjusting the infrared light source includes: increasing the intensity of the infrared light emitted by the infrared light source.
4 . The method of claim 1 , further comprising synchronizing the image sensor and the infrared light source to alternate between:
an unblock mode where: the image sensor is acquiring images; and the infrared light does not saturate the image sensor; and
a block mode where: the image sensor is not acquiring the images; and the infrared light saturates other image sensors.
5 . The method of claim 1 , wherein analyzing the images to determine whether the image sensor is saturated comprises determining whether given features are present in the images.
6 . A computing device comprising:
a controller communicatively coupled to an image sensor and a variable transmissivity screen, the variable transmissivity screen controllable to different transmissivity states; and
a computer-readable storage medium having stored thereon program instructions that, when executed by the controller, causes the controller to perform a set of operations comprising:
synchronizing the image sensor and the variable transmissivity screen to alternate between:
an unblock mode where: the image sensor acquires images through the variable transmissivity screen; and the variable transmissivity screen is controlled to an unblock mode transmissivity state that transmits light; and
a block mode where: the image sensor does not acquire the images; and the variable transmissivity screen is controlled to a block mode transmissivity state that at least partially blocks the light from being transmitted therethrough.
7 . The computing device of claim 6 , wherein the set of operations further comprises:
synchronizing between the unblock mode and the block mode according to a given pattern.
8 . The computing device of claim 6 , wherein the set of operations further comprises:
varying a pattern of synchronizing between the unblock mode and the block mode.
9 . The computing device of claim 6 , wherein the set of operations further comprises, prior to the synchronizing, performing a calibration process comprising:
varying a transmissivity state of the variable transmissivity screen in combination with the image sensor acquiring, through the variable transmissivity screen, calibration images of items behind the variable transmissivity screen;
when the calibration images include the items, storing a current transmissivity state as the unblock mode transmissivity state; and
when the calibration images do not include the items, storing a respective current transmissivity state as the block mode transmissivity state.
10 . The computing device of claim 9 , wherein the controller is further communicatively coupled to an infrared light source, and the calibration process further comprises:
varying a light intensity of the infrared light source while varying the transmissivity state of the variable transmissivity screen in combination with the image sensor acquiring, through the variable transmissivity screen, the calibration images of the items behind the variable transmissivity screen;
when the calibration images include the items, storing the current transmissivity state as the unblock mode transmissivity state and storing a current intensity as an unblock mode intensity; and
when the calibration images do not include the items, storing a respective current transmissivity state as the block mode transmissivity state and storing a respective current intensity as a block mode intensity.
11 . The computing device of claim 9 , wherein the set of operations further comprises:
repeating the calibration process when the images acquired through the variable transmissivity screen in the unblock mode, no longer include the items.
12 . The computing device of claim 9 , wherein the items comprise one or more of a facial features and license plate features.
13 . A system comprising:
an infrared light source;
a variable transmissivity screen controllable to different transmissivity states;
an image sensor; and
a computing device communicatively coupled to the infrared light source, the variable transmissivity screen and the image sensor, the computing device storing program instructions that, when executed by the computing device, causes the computing device to perform a set of operations comprising:
determining an unblock mode where: the image sensor acquires images through the variable transmissivity screen; and the combination of the infrared light source and the variable transmissivity screen are respectively controlled to: an unblock mode intensity where the image sensor is unsaturated; and an unblock mode transmissivity state that transmits light;
determining a block mode where: the image sensor does not acquire the images; and the combination of the infrared light source and the variable transmissivity screen are respectively controlled to: a block mode intensity where other image sensors are at least partially saturated; and a block mode transmissivity state that at least partially blocks the light from being transmitted therethrough, such that, in the block mode, the other image sensors are prevented from acquiring respective images that include items located behind the variable transmissivity screen; and
synchronizing the image sensor and a combination of the infrared light source and the variable transmissivity screen to alternate between the unblock mode and the block mode.
14 . The system of claim 13 , wherein the set of operations further comprises:
synchronizing between the unblock mode and the block mode according to a given pattern.
15 . The system of claim 13 , wherein the set of operations further comprises:
varying a pattern of synchronizing between the unblock mode and the block mode.
16 . The system of claim 13 , wherein the set of operations further comprises, prior to the synchronizing, performing a calibration process comprising:
varying a light intensity of the infrared light source while varying a transmissivity state of the variable transmissivity screen in combination with the image sensor acquiring, through the variable transmissivity screen, calibration images of the items behind the variable transmissivity screen;
when the calibration images include the items, storing a current intensity of the infrared light as the unblock mode intensity and storing a current transmissivity state as the unblock mode transmissivity state; and
when the calibration images do not include the items, storing a respective current intensity as the block mode intensity and storing a respective current transmissivity state as the block mode transmissivity state.
17 . The system of claim 16 , wherein the set of operations further comprises:
repeating the calibration process when the images acquired through the variable transmissivity screen in the unblock mode, no longer include the items.
18 . The system of claim 13 , wherein the unblock mode intensity comprises one or more of zero and a minimum possible intensity of the infrared light.
19 . The system of claim 13 , wherein the unblock mode intensity comprises a non-zero intensity of the infrared light, and that assists with illuminating the items located behind the variable transmissivity screen.