METHOD AND SYSTEM OF ADAPTABLE EXPOSURE CONTROL AND LIGHT PROJECTION FOR CAMERAS

• US 20160360074A1
• Filed: 09/09/2015
• Published: 12/08/2016
• Est. Priority Date: 06/02/2015
• Status: Active Grant

• Current Assignee: Sony Group Corp.
• Original Assignee: Intel Corporation
• Inventors: HICKS, RICHMOND, WINER, PAUL
• Granted Patent: US 10,721,420 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01B 11/25 by projecting a pattern, e.g. one or more lines, moiré fringes on the object G01B11/255 takes precedence ; image analysis for depth or shape recovery G06T7/50
• CPC Class Codes: G06T 2207/10048 Infrared image
• CPC Class Codes: G06T 7/521 from laser ranging, e.g. using interferometry; from the projection of structured light
• CPC Class Codes: H04N 13/254 in combination with electromagnetic radiation sources for illuminating objects
• CPC Class Codes: H04N 13/271 wherein the generated image signals comprise depth maps or disparity maps
• CPC Class Codes: H04N 2013/0081 Depth or disparity estimation from stereoscopic image signals
• CPC Class Codes: H04N 23/56 provided with illuminating means
• CPC Class Codes: H04N 23/73 by influencing the exposure time
• CPC Class Codes: H04N 5/33 Transforming infrared radiation cameras or camera modules for generating image signals from infrared radiation H04N23/20; circuitry of SSIS for transforming infrared radiation into image signals H04N25/20

Abstract

Techniques related to a method and system of adaptable exposure control and light projection for cameras are described herein.

Claims

1. A method of adaptable exposure control and light projection for cameras, comprising:

projecting light in multiple pulses in a single frame period, wherein the frame period is used to capture a single image of a scene;

performing multiple exposure times during the single frame period and at at least one sensor used to detect the scene; and

synchronizing the exposure times to the pulses so that a single exposure time corresponds to a single pulse duration for multiple individual pulses during the single frame period.

2. The method of claim 1 comprising projecting an infra-red light.

3. The method of claim 1 comprising emitting and sensing light at about 940 nm or about 939 nm to about 941 nm.

4. The method of claim 1 wherein the pulses are provided at a substantially uniform frequency throughout the frame period.

5. The method of claim 1 wherein the pulses are concentrated so that at least one non-pulsed duration exists during the frame period and that has a duration longer than a duration between adjacent pulses used multiple times during the frame period.

6. The method of claim 5 wherein the non-pulsed duration in a frame period is longer than the total duration of the pulses in the frame period.

7. The method of claim 5 wherein the pulses are bunched together in a single area of the frame period.

8. The method of claim 1 wherein the pulses are provided so that the pulses of a frame period has an average power of the frame period that is below a threshold average power, but a peak power of the pulses is above the threshold average power.

9. The method of claim 8 wherein the threshold is associated with a laser eye safety threshold.

10. The method of claim 1 wherein all exposure times in a frame period are synchronized to a pulse during the frame period.

11. The method of claim 1 comprising receiving a signal from the sensors associated with the detection of the projected light, and using the signal to perform depth measurement calculations.

12. The method of claim 1 wherein the light is projected as a geometrical pattern.

13. The method of claim 1 comprising projecting an infra-red light;

and emitting and sensing light at about 940 nm or about 939 nm to about 941 nm;

wherein at least one of;

the pulses are provided at a substantially uniform frequency throughout the frame period, and

the pulses are concentrated so that at least one non-pulsed duration exists during the frame period and that has a duration longer than a duration between adjacent pulses used multiple times during the frame period, wherein the non-pulsed duration in a frame period is longer than the total duration of the pulses in the frame period, wherein the pulses are bunched together in a single area of the frame period;

wherein the pulses are provided so that the pulses of a frame period has an average power of the frame period that is below a threshold average power, but a peak power of the pulses is above the threshold average power, wherein the threshold is associated with a laser eye safety threshold;

wherein all exposure times in a frame period are synchronized to a pulse during the frame period; and

the method comprising receiving a signal from the sensors associated with the detection of the projected light, and using the signal to perform depth measurement calculations, wherein the light is projected as a geometrical pattern.

14. A system comprising:

at least one projector to project a light pattern to provide features for a scene;

at least one sensor to detect the pattern;

at least one memory;

at least one processor communicatively and operatively coupled to the projector, sensor, and memory;

a light unit operated by the at least one processor and arranged to control the projector to project light in multiple pulses in a single frame period, wherein the frame period is used to capture a single image of a scene;

an exposure unit operated by the at least one processor and arranged to control the at least one sensor to perform multiple exposure times during the single frame period and at at least one sensor used to detect the scene; and

a synchronization unit operated by the at least one processor and arranged to synchronize the exposure times to the pulses so that a single exposure time corresponds to a single pulse duration for multiple individual pulses during the single frame period.

15. The system of claim 14 wherein the light is of a projection of infra-red light.

16. The system of claim 14 wherein the light is emitted at about 940 nm or about 939 nm to about 941 nm.

17. The system of claim 14 wherein the pulses are provided at a substantially uniform frequency throughout the frame period.

18. The system of claim 14 wherein the pulses are concentrated so that at least one non-pulsed duration exists during the frame period and that has a duration longer than a duration between adjacent pulses used multiple times during the frame period.

19. The system of claim 18 wherein the non-pulsed duration in a frame period is longer than the total duration of the pulses in the frame period.

20. The system of claim 18 wherein the pulses are bunched together in a single area of the frame period.

21. The system of claim 14 wherein the pulses are provided so that the pulses of a frame period has an average power of the frame period that is below a threshold average power, but a peak power of the pulses is above the threshold average power.

22. The system of claim 21 wherein the threshold is associated with a laser eye safety threshold.

23. The system of claim 14 wherein the light unit is to project an infra-red light;

and emit and sense light at about 940 nm or about 939 nm to about 941 nm;

wherein at least one of;

the pulses are provided at a substantially uniform frequency throughout the frame period, and

the pulses are concentrated so that at least one non-pulsed duration exists during the frame period and that has a duration longer than a duration between adjacent pulses used multiple times during the frame period, wherein the non-pulsed duration in a frame period is longer than the total duration of the pulses in the frame period, wherein the pulses are bunched together in a single area of the frame period;

wherein the pulses are provided so that the pulses of a frame period has an average power of the frame period that is below a threshold average power, but a peak power of the pulses is above the threshold average power, wherein the threshold is associated with a laser eye safety threshold;

wherein all exposure times in a frame period are synchronized to a pulse during the frame period; and

the system being arranged to receive a signal from the sensors associated with the detection of the projected light, and use the signal to perform depth measurement calculations, wherein the light is projected as a geometrical pattern.

24. A computer-readable medium having stored thereon instructions that when executed cause a computing device to:

project light in multiple pulses in a single frame period, wherein the frame period is used to capture a single image of a scene;

perform multiple exposure times during the single frame period and at at least one sensor used to detect the scene; and

synchronize the exposure times to the pulses so that a single exposure time corresponds to a single pulse duration for multiple individual pulses during the single frame period.

25. The computer-readable medium of claim 24 wherein the instructions cause the computing device to:

project an infra-red light; and

emit and sense light at about 940 nm or about 939 nm to about 941 nm;

wherein at least one of;

the pulses are provided at a substantially uniform frequency throughout the frame period, and

the pulses are concentrated so that at least one non-pulsed duration exists during the frame period and that has a duration longer than a duration between adjacent pulses used multiple times during the frame period, wherein the non-pulsed duration in a frame period is longer than the total duration of the pulses in the frame period, wherein the pulses are bunched together in a single area of the frame period;

wherein the pulses are provided so that the pulses of a frame period has an average power of the frame period that is below a threshold average power, but a peak power of the pulses is above the threshold average power, wherein the threshold is associated with a laser eye safety threshold;

wherein all exposure times in a frame period are synchronized to a pulse during the frame period; and

wherein the instructions cause the computing device to receive a signal from the sensors associated with the detection of the projected light, and use the signal to perform depth measurement calculations, wherein the light is projected as a geometrical pattern.