Method of characterizing a light source and a mobile device

• US 9,613,433 B2
• Filed: 04/07/2014
• Issued: 04/04/2017
• Est. Priority Date: 04/15/2013
• Status: Expired due to Fees

• Current Assignee: Signify Holding B.V. (Signify N.V.)
• Original Assignee: Philips Lighting BV (Koninklijke Philips N.V.)
• Inventors: Pelzer, Heiko, Nolan, Julian Charles, Van Eeuwijk, Alexander Henricus Waltherus, Vanden Wyngaert, Hilbrand
• Primary Examiner(s): Kim, Hee-Yong
• Application Number:
  US14/782,909
• Publication Number:
  US 20160042531A1
• Time in Patent Office: 1,093 Days
• Field of Search: 348135
• CPC Class Codes: G06T 2207/10004 Still image; Photographic image
• CPC Class Codes: G06T 7/60 Analysis of geometric attributes
• CPC Class Codes: G06T 7/90 Determination of colour characteristics
• CPC Class Codes: H04N 23/80 Camera processing pipelines; Components thereof
• CPC Class Codes: H04N 23/90 Arrangement of cameras or camera modules, e.g. multiple cameras in TV studios or sports stadiums
• CPC Class Codes: H05B 47/23 of two or more light sources connected in series
• CPC Class Codes: H05B 47/29 Circuits providing for substitution of the light source in case of its failure

Abstract

A method of and a device for characterizing a light source and a method of selecting a replacement light source are provided. The method obtains (102) a first image of a light source in operation, obtains (106) a second image of the illuminated environment, and obtains (104, 108) first camera settings and second camera settings of the optical system and image processing system of the respective first and second camera at the respective moments in time that the first image and the second image was obtained. The first image, the second image, and the first and second camera settings are analyzed (110) to estimate characteristics of the light source. The characteristics of the light source may be used to propose a replacement light source and characteristics of the proposed replacement light source may be used to simulate the effect of the replacement light source on the illuminated environment.

Claims

1. A method of characterizing a light source, the light source comprising a light emitter for emitting light, the method comprises the stages of

obtaining a first image of the light source in operation by means of a first camera, the first image is obtained from a first position (P1) in a first direction,

obtaining first camera settings, wherein the first camera settings represent parameters of an image processing system and of an optical system of the first camera used at the moment in time when the first image was obtained,

obtaining a second image of an illuminated environment being illuminated by the light source by means of a second camera, the second image is obtained from a second position (P2) in a second direction different from the first direction,

obtaining second camera settings, wherein the second camera settings represent parameters of an image processing system and of an optical system of the second camera used at the moment in time when the second image was obtained,

analyzing the first image and analyzing the first camera settings to estimate first parameters of the light source, wherein the first parameters of the light source relate to characteristics of light emitted by the light emitter,

wherein, in the stage of analyzing the first image and analyzing the first camera settings, the second image and the second camera settings are also analyzed to estimate second parameters of the light source and to more accurately estimate the first parameters of the light source, wherein the second parameters of the light source relate to characteristics of a light beam emitted by the light source, the second parameters comprise information relating to a shape of the light beam.

2. The method according to claim 1, wherein the second camera is the first camera and the method further comprising the stage of repositioning the first camera after obtaining the first image to the second position (P2) in the second direction for obtaining the second image.

3. The method according to claim 1, wherein the second position (P2) is substantially identical to the first position (P1) and wherein the second direction is substantially opposite to the first direction.

4. The method according to claim 1, wherein,

characteristics of light emitted by the light emitter comprise at least one of:

emitted light intensity by the light source, light emission spectrum of the light source, color point of the emitted light, color temperature of the emitted light,

and, optionally, the first parameters comprise geometrical parameters of the light source, geometrical parameters of the light source comprise at least one of;

shape of light emitting surface of the light source, size of the light source, parameters of visible optical elements in the light source, characteristics of the luminaire in which the light source is provided, the characteristics of the luminaire comprise a shape, a size, a mounting and a type of luminaire.

5. The method according to claim 1 further comprising the stage of:

analyzing the second image to determine whether the illuminated environment is also illuminated by additional light sources, the additional light sources comprising additional light emitters,

obtaining additional first images of the additional light sources,

obtaining additional first camera settings, wherein the additional first camera settings represent the parameters of the image processing system and of the optical system of the first camera used at the moment of time when the additional first images were obtained,

wherein, in the stage of analyzing the first image and analyzing the first camera settings together with the second image and the second camera settings, the additional first images and the additional first camera settings are also analyzed to estimate the influence of the additional light sources on the illuminated environment for more accurately estimating the second parameters and/or first parameters of the light source (204).

6. The method according to claim 1 further comprises the stage of:

controlling the light source into a second operational mode, wherein the light source is controllable in a first operational mode and the second operational mode, each one of the first operational mode and the second operational mode relates to a specific light emission, the light emission of the first operational mode being different from the light emission of the second operational mode, and wherein the first image is obtained from the light source when the light source was operating in the first operational mode,

obtaining a further first image of the light source in operation in the second operational mode by means of the first camera,

obtaining further first camera settings, wherein the further first camera settings represent the parameters of the image processing system and of the optical system of the first camera used at the moment in time when the further first image was obtained,

analyzing the further first image and analyzing the further first camera settings to estimate further parameters of the light source in relation to the second operational mode, wherein the further parameters of the light source relate to characteristics of light emitted by the light emitter and/or relate to geometrical parameters of the light source.

7. The method according to claim 1, wherein the stages of obtaining the first image, obtaining the additional first images, and/or obtaining the further first image comprise the stages of:

instructing a user to direct the first camera to, respectively, the light source, the additional light source or the light source operating the second operational mode,

detecting on basis of information of the image processing system whether the amount of received light exceeds a minimum value,

obtaining the respective image when the amount of received light exceeds the minimum value.

8. The method according to claim 1, wherein the stage of analyzing the first image and analyzing the first camera settings to estimate the first parameters of the light source comprises the stages of:

comparing the first image with images of light sources stored in a database to find an image of a light source that is similar to the first image, the database also stores together with the images of the light sources information about the parameters of the respective light sources,

obtaining the first parameters from the database by obtaining parameters of the light source of the found image that is similar to the first image.

9. The method according to claim 1, wherein the first camera is also configured to image the light source in the infrared spectral range to obtain a heat signature of the light source and the stage of obtaining the first image comprises obtaining a heat signature, and wherein in the stage of analyzing the first image and analyzing the first camera settings to estimate the first parameters of the light source, the heat signature is also analyzed to obtain further characteristics of the light source which relate to the operational conditions of the light source.

10. The method according to claim 1, wherein the first camera and/or the second camera are a hyper spectral camera.

11. A method of selecting a replacement light source, the method comprises the stages of the method of characterizing a light source according to claim 1 and comprises the further stages of:

selecting from a list of replacement light sources and/or replacement light emitters a replacement light source and/or a replacement light emitter, wherein the replacement light source and/or the replacement light emitter have at least one parameter that is similar to one of the first parameters and/or the second parameters of the light source,

proposing the selected replacement light source and/or the selected replacement light emitter to a user.

12. The method of selecting a replacement light source according to claim 11 further comprising the stage of:

simulating an influence of the selected replacement light source and/or the selected replacement light emitter on the illuminated environment,

creating an adapted second image showing the result of the simulating of the influence of the selected replacement light source and/or the selected replacement light emitter on the environment,

presenting the adapted second image to the user.

13. The method of selecting a replacement light source according to claim 11, wherein the selected replacement light source and/or the selected replacement light emitter may operate in a third operational mode and a fourth operational mode, in each one of the third operational mode and the fourth operational mode the selected replacement light source and/or the selected replacement light emitter emits a specific light emission, the light emission of the third operational mode being different from the light emission of the fourth operational mode, and the obtained adapted second image relates to the third operational mode of the selected replacement light source and/or the selected replacement light emitter,

the method further comprising the stages of:

simulating an influence of the selected replacement light source and/or the selected replacement light emitter on the environment, the simulating relates to the operation of the selected replacement light source and/or the selected replacement light emitter in the fourth operational mode,

creating a further adapted second image showing the result of the simulating of the influence of the selected replacement light source and/or the selected replacement light emitter on the environment,

presenting the further adapted second image to the user.

14. A computer-readable, non-transitory medium having stored therein instructions for causing a processing unit to execute a method of characterizing a light source, the light source comprising a light emitter for emitting light, the medium comprising code for:

obtaining a first image of the light source in operation by means of a first camera, the first image is obtained from a first position (P1) in a first direction,

obtaining first camera settings, wherein the first camera settings represent parameters of an image processing system and of an optical system of the first camera used at the moment in time when the first image was obtained,

obtaining a second image of an illuminated environment being illuminated by the light source by means of a second camera, the second image is obtained from a second position (P2) in a second direction different from the first direction,

obtaining second camera settings, wherein the second camera settings represent parameters of an image processing system and of an optical system of the second camera used at the moment in time when the second image was obtained,

analyzing the first image and analyzing the first camera settings to estimate first parameters of the light source, wherein the first parameters of the light source relate to characteristics of light emitted by the light emitter,

wherein, in the stage of analyzing the first image and analyzing the first camera settings, the second image and the second camera settings are also analyzed to estimate second parameters of the light source and to more accurately estimate the first parameters of the light source, wherein the second parameters of the light source relate to characteristics of a light beam emitted by the light source, the second parameters comprise information relating to a shape of the light beam.

15. A computer-readable, non-transitory medium having stored therein instructions for causing a processing unit to execute a method of selecting a replacement light source, the medium comprises the code of the medium of characterizing a light source according to claim 14, and the medium the further includes code for:

selecting from a list of replacement light sources and/or replacement light emitters a replacement light source and/or a replacement light emitter, wherein the replacement light source and/or the replacement light emitter have at least one parameter that is similar to one of the first parameters and/or the second parameters of the light source,

proposing the selected replacement light source and/or the selected replacement light emitter to a user.