A modulation control method for a filter device for avoiding flicker appearing in streamed video images before acquiring images, includes setting the exposure time to be equal or longer than an oscillating light source's period duration or to be as long as possible between two frames in the image acquisition of streamed video images, polarizing of incoming light in a first polarizer to turn into polarized light with a first polarization, altering the polarization of the light with the first polarization in an electro- or magneto-optic modulator by an angle α to turn into light with a second polarization, and reducing an amount of light with the second polarization in a second polarizer.

A system and method for an imaging circadiometer that measures the spatial distribution of eye-mediated, non-image-forming optical radiation within the visible spectrum.

An image processing method including: capturing changes in a monitored scene; and performing a sparse feature calculation on the changes in the monitored scene to obtain a sparse feature map.

Techniques and apparatuses are described for reducing a flicker effect of multiple light sources in an image captured with an imaging device. A lighting frequency associated with each of the multiple light sources is detected and prioritized relative to a flicker effect upon the image to identify at least a first-prioritized lighting frequency and a second-prioritized lighting frequency. A first exposure-time factorization set is determined for the first-prioritized lighting frequency, and a second exposure-time factorization set is determined for the second-prioritized lighting frequency. An exposure time of the imaging device is adjusted to an exposure time identified in the first exposure-time factorization set that matches, or aligns near-to-matching, an exposure time identified in the second exposure-time factorization set.

Techniques and apparatuses are described for reducing a flicker effect of multiple light sources in an image captured with an imaging device. A lighting frequency associated with each of the multiple light sources is detected and prioritized relative to a flicker effect upon the image to identify at least a first-prioritized lighting frequency and a second-prioritized lighting frequency. A first exposure-time factorization set is determined for the first-prioritized lighting frequency, and a second exposure-time factorization set is determined for the second-prioritized lighting frequency. An exposure time of the imaging device is adjusted to an exposure time identified in the first exposure-time factorization set that matches, or aligns near-to-matching, an exposure time identified in the second exposure-time factorization set.

The present disclosure relates to systems and methods for monitoring control. The systems may obtain one or more monitoring images associated with a monitoring region captured by a monitoring device. The systems may determine whether a target event occurs in the monitoring region based on the one or more monitoring images. In response to determining that the target event occurs in the monitoring region, the systems may obtain a target time period associated with operations of a warning light associated with the monitoring device based on at least one parameter of the monitoring device. The systems may control the operations of the warning light based on the target time period.

The present disclosure relates to systems and methods for monitoring control. The systems may obtain one or more monitoring images associated with a monitoring region captured by a monitoring device. The systems may determine whether a target event occurs in the monitoring region based on the one or more monitoring images. In response to determining that the target event occurs in the monitoring region, the systems may obtain a target time period associated with operations of a warning light associated with the monitoring device based on at least one parameter of the monitoring device. The systems may control the operations of the warning light based on the target time period.

Hyperspectral videostroboscopy imaging is described. A system includes an emitter for emitting pulses of electromagnetic radiation and an image sensor comprising a pixel array for sensing reflected electromagnetic radiation. The system includes a controller configured to cause the emitter to emit the pulses of electromagnetic radiation at a strobing frequency determined based on a vibration frequency of vocal cords of a user. The system is such that at least a portion of the pulses of electromagnetic radiation emitted by the emitter comprises electromagnetic radiation having a wavelength from about 513 nm to about 545 nm, from about 565 nm to about 585 nm, or from about 900 nm to about 1000 nm.

An apparatus comprises: a sensor that shoots a subject and outputs an image; a shift unit that shifts a position on the sensor of an image of the subject incident on the sensor; and a detection unit that detects flicker based on partial images in a same partial region of a plurality of images consecutively obtained from the sensor. In a case where the sensor shoots the plurality of images while the shift unit is shifting the position of the image of the subject, the detection unit selects the partial region so that a change of the image of the subject in the partial region caused by the shift becomes small between the plurality of images.

A two-dimensional flicker measurement apparatus includes: a first calculation unit that calculates a flicker amount of each of a plurality of measurement regions set on a measurement target based on a photometric quantity obtained by performing photometry in the measurement target at a first sampling frequency; a second calculation unit that calculates a flicker amount of a predetermined measurement region set on the measurement target based on a photometric quantity obtained by performing photometry in the predetermined measurement region at a second sampling frequency; and a correction unit that corrects the flicker amount of each of the plurality of measurement regions calculated by the first calculation unit using a correction coefficient defined by the flicker amount calculated by the second calculation unit and a flicker amount of the predetermined measurement region calculated based on a photometric quantity obtained by performing photometry in the predetermined measurement region at the first sampling frequency.