Apparatus and methods for measuring and controlling illumination for imaging objects, performances and the like

• US 20020180973A1
• Filed: 04/03/2002
• Published: 12/05/2002
• Est. Priority Date: 04/04/2001
• Status: Abandoned Application

• Current Assignee: Tidal Photonics Incorporated
• Original Assignee: Tidal Photonics Incorporated
• Inventors: Stange, Ulrich, MacKinnon, Nicholas B.
• Application Number:
  US10/116,705
• Publication Number:
  US 20020180973A1
• Time in Patent Office: Days
• US Class Current: 356/425
• CPC Class Codes: H05B 47/155 Coordinated control of two or more light sources
• CPC Class Codes: H05B 47/165 following a pre-assigned programmed sequence; Logic control [LC]

Abstract

Scene illumination analysis and control systems and methods that can measure the intensity and wavelength dependent distribution of light illuminating a scene, determine any differences between desired illumination and actual illumination, determine appropriate remedies to adjust illumination and automatically control, and adjust illumination to effect those remedies if desired. Associated software, measurement and control devices, for example appropriate accessories for calibrating the measurement devices, collecting and controlling measurements, analyzing measurements and comparing them to established criteria. The systems and methods can also calculate expected scene illumination based on geographic location, altitude, time of year and day, and weather or other environmental factors, and provides analysis and reports to allow the user to assess scene illumination and plan for in-production or post-production correction of video or film images.

Claims

1. An automated method that controls relative color characteristic values of a scene illumination at a scene, comprising:

measuring actual relative color characteristic values of illumination at the scene to provide measured relative color characteristic values;

automatically comparing in at least one controller the measured relative color characteristic values with target relative color characteristic values stored in at least one computer-readable database;

automatically determining in the at least one controller whether there is at least one substantial difference between the measured relative color characteristic values and the target relative color characteristic values;

adjusting illumination characteristics from at least one light source illuminating the scene to provide improved illumination comprising improved relative color characteristic values in the scene illumination that more closely match the target relative color characteristic values.

2. The method of claim 1 wherein the method further comprises storing the measured relative color characteristic values in at least one computer-readable medium, the adjusting is performed automatically, and the measuring comprises using a spectroradiometer to obtain the measured relative color characteristic values.

3. The method of claim 1 or 2 wherein the target relative color characteristic values correlate to the relative color characteristics of a specific geographic location comprising information relating to latitude, longitude and altitude of the location.

4. The method of claim 1 or 2 wherein the target relative color characteristics correlate to at least one of date, time of day, and angle of solar or lunar illumination.

5. The method of claim 1 or 2 wherein the target relative color characteristics correlate to at least one environmental condition selected from the group consisting of cloudiness, rain, dust, humidity, temperature and shade.

6. The method of claim 1 or 2 wherein the target relative color characteristics correlate to at least one artificial light source.

7. The method of claim 1 or 2 wherein the method further comprises applying tristimulus functions to the measured relative color characteristic values and the target relative color characteristic values to determine whether there is the at least one substantial difference between the measured relative color characteristic values and the target relative color characteristic values.

8. The method of claim 7 wherein the method further comprises applying tristimulus functions to determine at least one appropriate spectral change to correct for the at least one substantial difference between the measured relative color characteristic values and the target relative color characteristic values to provide the improved illumination.

9. The method of claim 1 or 2 wherein the method further comprises assessing at least one available remedy from a database of available remedies to correct for the at least one substantial difference.

10. The method of claim 1 or 2 wherein the adjusting further comprises selectively increasing or decreasing a substantial amount of one or two of red light, blue light and green light in the scene illumination.

11. The method of claim 10 wherein the selectively increasing or decreasing comprises increasing or decreasing at least one of the emission intensity, spectral output, and filtering characteristics of a light source emitting light into the scene illumination.

12. The method of claim 1 or 2 wherein the measured relative color characteristic values are transmitted via hardwire to the controller.

13. The method of claim 1 or 2 wherein the measured relative color characteristic values are transmitted via wireless to the controller.

14. The method of claim 1 or 2 wherein the method further comprises recording the improved relative color characteristic values as a baseline illumination value.

15. The method of claim 14 wherein the method further comprises comparing a later-obtained measurement of the relative color characteristic values of the scene illumination against the baseline illumination value to determine if the later-obtained measurement varies more than a threshold level from the baseline illumination value.

16. The method of claim 15 wherein the method further comprises, if the later-obtained measurement varies more than the threshold level from the baseline illumination value, then automatically adjusting the scene illumination to bring the relative color characteristic values within the threshold level.

18. The method of claim 17 wherein the method further comprises storing the measured relative color characteristic values in at least one computer-readable medium, the adjusting is performed automatically, and the measuring comprises using a spectroradiometer to obtain the measured relative color characteristic values.

19. The method of claim 17 or 18 wherein the target relative color characteristic values correlate to the relative color characteristics of a specific geographic location comprising information relating to latitude, longitude and altitude of the location.

20. The method of claim 17 or 18 wherein the target relative color characteristics correlate to at least one of date, time of day, and angle of solar or lunar illumination.

21. The method of claim 17 or 18 wherein the target relative color characteristics correlate to at least one environmental condition selected from the group consisting of cloudiness, rain, dust, humidity, temperature and shade.

22. The method of claim 17 or 18 wherein the target relative color characteristics correlate to at least one artificial light source.

23. The method of claim 17 or 18 wherein the method further comprises applying tristimulus functions to the measured relative color characteristic values and the target relative color characteristic values to determine whether there is the at least one substantial difference between the measured relative color characteristic values and the target relative color characteristic values.

24. The method of claim 23 wherein the method further comprises applying tristimulus functions to determine at least one appropriate spectral change to correct for the at least one substantial difference between the measured relative color characteristic values and the target relative color characteristic values to provide the improved illumination.

25. The method of claim 17 or 18 wherein the method further comprises assessing at least one available remedy from a database of available remedies to correct for the at least one substantial difference.

26. The method of claim 17 or 18 wherein the adjusting further comprises selectively increasing or decreasing a substantial amount of one or two of red light, blue light and green light in the recorded image of the scene.

27. The method of claim 17 or 18 wherein the measured relative color characteristic values are transmitted via hardwire to the controller.

28. The method of claim 17 or 18 wherein the measured relative color characteristic values are transmitted via wireless to the controller.

29. The method of claim 17 or 18 wherein the method further comprises recording the improved relative color characteristic values as a baseline illumination value.

30. The method of claim 29 wherein the method further comprises comparing a later-obtained measurement of the relative color characteristic values of the scene illumination against the baseline illumination value to determine if the later-obtained measurement varies more than a threshold level from the baseline illumination value.

31. The method of claim 30 wherein the method further comprises, if the later-obtained measurement varies more than the threshold level from the baseline illumination value, then automatically adjusting the recording of the scene to bring the relative color characteristic values within the threshold level.

42. Computer-implemented programming that performs the method of any one of claims 1, 2, 17, 18, 32, 35, 38 or 40.

43. A controller comprising computer-implemented programming that performs the method of any one of claims 1, 2, 17, 18, 32, 35, 38 or 40.

44. A system for illuminating of a scene comprising:

a spectral sensor;

a controller according to claim 43 operably connected to the spectral sensor and at least one light source.

17. An automated method that controls relative color characteristic values of a scene illumination, comprising:

measuring actual relative color characteristic values of illumination at the desired scene to provide measured relative color characteristic values and storing the measured relative color characteristic values in at least one computer-accessible database;

automatically comparing in at least one controller the measured relative color characteristic values with target relative color characteristic values stored in at least one computer-readable database;

automatically determining in the at least one controller whether there is at least one substantial difference between the measured relative color characteristic values and the target relative color characteristic values;

adjusting recording characteristics of at least one recording imaging device recording an image of the scene to provide improved apparent illumination comprising improved relative color characteristic values of the scene illumination as recorded by the recording imaging device that more closely match the target relative color characteristic values.

32. A method of making a database comprising target relative color characteristic values for a desired geographic position, a desired date and time, comprising:

determining a first wavelength dependent energy distribution based on latitude, longitude, altitude, date of year and time of day, thereby providing an angle of solar illumination incident on the scene and an estimate of the quantity of atmosphere the solar illumination traverses;

calculating appropriate relative color characteristic values of the wavelength dependent energy distribution using multistimulus values for the first wavelength dependent energy distribution to provide target relative color characteristic values;

recording the target relative color characteristic values as the database in a computer-readable database.

33. The method of claim 32 wherein the database further comprises target relative color characteristic values for desired environmental conditions, and the method further comprises:

determining a second wavelength dependent energy distribution based on at least one environmental condition selected from the group consisting of cloudiness, rain, dust, humidity, temperature and shade.

34. A method of selecting target relative color characteristic values for a scene illumination, comprising reviewing appropriate relative color characteristic values in a computer-readable database produced according to the method of claim 32 or 33, identifying a target appropriate relative color characteristic values corresponding to the target relative color characteristic values, and selecting target appropriate relative color characteristic values.

36. The method of claim 35 wherein the illumination equipment is selected from the group consisting of a white light source, a tunable light source, a light filter, a wavelength dispersive element, a spatial light modulator, and a light source emitting a single wavelength or a wavelength band limited to single color of light.

37. The method of claim 36 wherein the target relative color characteristic values are obtained from a database produced according to the method of claim 32 or 33.

39. The method of claim 38 wherein the method further comprises, between the calculating and the recording, comparing the measured relative color characteristic values to target relative color characteristic values and determining whether there is at least one substantial difference and adjusting at least one of the actual scene illumination and the recording of the scene if there is at least one substantial difference until the at least one of the actual scene illumination and the recording of the scene surpasses a desired value to provide an acceptable apparent scene illumination.

35. A method of identifying illumination equipment to illuminate a desired scene, comprising:

providing target relative color characteristic values for the desired scene;

providing a computer-readable database comprising known relative color characteristic values for a plurality of illumination equipment at least one of which is able to supply the target relative color characteristic values;

comparing the target relative color characteristic values to the database; and

,

identifying acceptable illumination equipment able to supply the target relative color characteristic values.

38. A method of establishing scene baseline values comprising target relative color characteristic values of a scene illumination, comprising:

illuminating a scene;

measuring actual scene illumination;

calculating the relative color characteristic values of the actual scene illumination to provide measured relative color characteristic values;

recording the measured relative color characteristic values in a computer-readable medium as scene baseline values.

40. A computer-implemented method of adjusting illumination of a scene after measurement of unacceptable multistimulus values of relative color characteristic values of the scene comprising:

providing the measurement comprising the unacceptable multistimulus values;

comparing the unacceptable multistimulus values to a range of dynamic adjustment capabilities of illumination equipment that is illuminating the scene;

automatically adjusting the illumination equipment under feedback control until the multistimulus values of the scene reach an acceptable level.

41. The method of claim 40 wherein the multistimulus function is a tristimulus function.