Abstract: An optical system comprises a lens system having at least one movable lens; a lens housing having an opening, the lens housing attachable to an image sensor so that the lens, the opening, and the image sensor are arrangeable along an axis with the opening between the lens and the image sensor; a probe extending towards the opening and that is fixed in relation to the lens; an actuation system for moving the lens along the axis and the probe parallel with the axis, so that the probe reaches out to a location where the image sensor is arrangeable; and a control system for controlling the actuation system to move the lens and the probe and to detect that a motion of the lens and the probe is prevented by the probe hitting a surface fixed in relation to the image sensor.

Abstract: A method of activating an object-specific action comprises obtaining, based on image analysis of acquired images, a plurality of values of a movement characteristic, each value representing a moving object detected in the acquired images; receiving an input signal from a user input device, wherein the input signal represents a value of the movement characteristic for the user input device; comparing the value of the movement characteristic for the user input device with each value of the movement characteristics for the moving objects, and determining the moving object corresponding to the closest value of movement characteristic as a selected moving object; and activating the object-specific action for the selected moving object.

Abstract: An arrangement for determining an amount of light reaching an image sensor of a video camera is disclosed. The video camera comprises an imaging lens system guiding a beam path towards an image sensor and has an aperture plane where a variable aperture is arranged. The inventive arrangement comprises a light sensor arranged to probe light intensity continuously from a portion of the beam path, which portion is located in or near the aperture plane of the imaging lens system.

Abstract: Methods and apparatus, including computer program products, for determining a presence of an object located close to a lens (301) of a camera monitoring a scene. A first infrared illumination source (302) arranged to illuminate the scene from a first angle is activated. A first image (304) is acquired by the image capturing device (300). The first infrared illumination source (302) is deactivated, and a second infrared illumination source (306) arranged to illuminate the scene from a second angle is activated. A second image (308) is acquired by the image capturing device (300). Intensity information of the first image (304) and the second image (308) is compared to determine the presence of an object located close to the lens (301).

Abstract: An arrangement for determining an amount of light reaching an image sensor of a video camera, the video camera comprising an imaging lens system guiding a beam path towards an image sensor, wherein the arrangement comprises a transparent probing element through which the beam path passes on its way to the image sensor, and a light sensor arranged in an end of the transparent probing element. The light sensor is arranged to collect light being scattered or reflected in the transparent probing element.

Abstract: A camera for introducing light pulses in an image stream, comprising an image sensor arranged to capture an image stream, the image sensor comprising a plurality of pixels arranged to capture light of a first wavelength range. The at least one of the plurality of pixels is covered by a first material which is arranged to transform light of a second wavelength range to light of the first wavelength range. Further the camera comprises a first light source arranged to emit light pulses of light of the second wavelength range onto the first material, thereby causing the image sensor to register light pulses in the at least one pixel covered by the first material.

Abstract: An arrangement for determining an amount of light reaching an image sensor of a video camera, the video camera comprising an imaging lens system guiding a beam path towards an image sensor, wherein the arrangement comprises a transparent probing element through which the beam path passes on its way to the image sensor, and a light sensor arranged in an end of the transparent probing element. The light sensor is arranged to collect light being scattered or reflected in the transparent probing element.

Abstract: An arrangement for determining an amount of light reaching an image sensor of a video camera is disclosed. The video camera comprises an imaging lens system guiding a beam path towards an image sensor and has an aperture plane where a variable aperture is arranged. The inventive arrangement comprises a light sensor arranged to probe light intensity continuously from a portion of the beam path, which portion is located in or near the aperture plane of the imaging lens system.

Abstract: A method of activating an object-specific action comprises obtaining, based on image analysis of acquired images, a plurality of values of a movement characteristic, each value representing a moving object detected in the acquired images; receiving an input signal from a user input device, wherein the input signal represents a value of the movement characteristic for the user input device; comparing the value of the movement characteristic for the user input device with each value of the movement characteristics for the moving objects, and determining the moving object corresponding to the closest value of movement characteristic as a selected moving object; and activating the object-specific action for the selected moving object.

Abstract: A camera for introducing light pulses in an image stream, comprising an image sensor arranged to capture an image stream, the image sensor comprising a plurality of pixels arranged to capture light of a first wavelength range. The at least one of the plurality of pixels is covered by a first material which is arranged to transform light of a second wavelength range to light of the first wavelength range. Further the camera comprises a first light source arranged to emit light pulses of light of the second wavelength range onto the first material, thereby causing the image sensor to register light pulses in the at least one pixel covered by the first material.

Abstract: Methods and apparatus, including computer program products, for determining a presence of an object located close to a lens (301) of a camera monitoring a scene. A first infrared illumination source (302) arranged to illuminate the scene from a first angle is activated. A first image (304) is acquired by the image capturing device (300). The first infrared illumination source (302) is deactivated, and a second infrared illumination source (306) arranged to illuminate the scene from a second angle is activated. A second image (308) is acquired by the image capturing device (300). Intensity information of the first image (304) and the second image (308) is compared to determine the presence of an object located close to the lens (301).

Abstract: The disclosure relates to a method, apparatus and system for detecting and reducing the effects of color fringing in digital video acquired by a camera comprising an iris. The method comprises: acquiring, by the camera, a first digital image frame using a first camera setting, including a first iris aperture size; acquiring, by the camera, a second digital image frame using a second camera setting, including a second iris aperture size, wherein the second aperture size is smaller than the first aperture size; comparing the first and the second digital image frame, at least a specific color component thereof; localizing regions having a disproportional intensity ratio in the specific color component between the first digital image frame and the second digital image frame; and reducing the specific color component in the localized regions for subsequently acquired digital image frames.

Abstract: A camera comprising: an aperture; an image sensor comprising a plurality of pairs of pixels where in each pair: a first pixel is configured such that it detects radiation which has entered the camera through the aperture to the image sensor via a first radiation path, and a second pixel is configured such that it detects radiation which has entered the camera through the aperture to the image sensor via a second radiation path, the second radiation path being different from the first radiation path; and a filter arranged in the vicinity of the aperture, wherein the filter comprises a first portion configured to block IR-radiation or visible light and a second portion configured to be transparent to wavelengths that are blocked by the first portion, wherein radiation passing the first portion travels to the first pixels, and radiation passing the second portion travels to the second pixels.

Abstract: A method and assembly produce color images of a scene captured by an image sensor exposed to visible light as well as IR radiation. A first image is captured with a first proportion of an iris aperture covered by an IR-cut filter. A first amount of radiation captured in the first image is determined and a second image captured with a second proportion of the iris covered by the IR-cut filter. A second amount of radiation captured in the second image is determined and a proportion of IR radiation is calculated in the scene based on the first amount of light, the second amount of light, the first IR-cut filter proportion, and the second IR-cut filter proportion. An IR contribution is removed from an image by using the calculated proportion of IR radiation.

Abstract: An infrared (IR) filter arrangement for a camera having an associated IR illuminator, the arrangement comprising: a fixedly arranged bandpass IR filter filtering out IR frequencies other than those from the IR illuminator; and an IR cut filter at least blocking any IR wavelength transmitted by the fixed band-pass filter, the IR filter being integrated in a diaphragm of the camera, such that closing of the diaphragm aperture entails an increased relative proportion of the diaphragm aperture being covered by the IR cut filter, and opening of the diaphragm aperture entails a decreased relative proportion of the diaphragm aperture being covered by the IR cut filter.

Abstract: The disclosure relates to a method, apparatus and system for detecting and reducing the effects of color fringing in digital video acquired by a camera comprising an iris. The method comprises: acquiring, by the camera, a first digital image frame using a first camera setting, including a first iris aperture size; acquiring, by the camera, a second digital image frame using a second camera setting, including a second iris aperture size, wherein the second aperture size is smaller than the first aperture size; comparing the first and the second digital image frame, at least a specific color component thereof; localizing regions having a disproportional intensity ratio in the specific color component between the first digital image frame and the second digital image frame; and reducing the specific color component in the localized regions for subsequently acquired digital image frames.

Abstract: A method and assembly produce color images of a scene captured by an image sensor exposed to visible light as well as IR radiation. A first image is captured with a first proportion of an iris aperture covered by an IR-cut filter. A first amount of radiation captured in the first image is determined and a second image captured with a second proportion of the iris covered by the IR-cut filter. A second amount of radiation captured in the second image is determined and a proportion of IR radiation is calculated in the scene based on the first amount of light, the second amount of light, the first IR-cut filter proportion, and the second IR-cut filter proportion. An IR contribution is removed from an image by using the calculated proportion of IR radiation.

Abstract: A method for sequential control of a diaphragm arrangement of a camera, the arrangement comprising a diaphragm, and an integrated IR cut filter always covering at least a portion of an aperture opening of the diaphragm, comprising: initiating closing or opening of the diaphragm; detecting an amount of incident radiation when the diaphragm has an initial aperture opening; shifting the aperture opening to an intermediate aperture opening to alter the ratio between visible light and infrared radiation passing the diaphragm; detecting an amount of incident radiation following the shift; calculating a composition of visual light and infrared radiation in the scene from the detected amounts of incident radiation and a calculated ratio between visible light and infrared radiation when having the initial aperture opening and the intermediate aperture opening, respectively; and shifting the aperture opening of the diaphragm to a new position.

Abstract: A method and apparatus for determining a focal-length setting of a lens mounted to a camera. In a method for determining a focal-length of a lens mounted to a camera, a distorted image of a scene is captured. A distortion-correction function is applied on the distorted image or on a portion of the distorted image. A most representative distortion-correction function is identified and a current focal-length setting for the lens is identified by correlating the identification to a data compilation.

Abstract: In a method for image stabilization a number of operations are performed to stabilize an image and to output a focal length value. The steps include capturing video by means of a video camera with unknown focal length running an image stabilization process operating on an input from a hardware detector detecting the displacement of the camera and on an adjustable focal length value. Inter-image displacement is corrected based on the input from the hardware detector and the adjustable focal length value. By evaluating the displacement and adjusting the focal length value until a satisfactory image stabilization is achieved a value of the focal length may be output.