Depth map generator
The invention describes a depth map generator comprising an array comprising a plurality of individually addressable array elements, wherein an array element comprises a semiconductor emitter or a reflector arranged to reflect light emitted by a semiconductor emitter; a driver realised to switch an array element according to a predefined illumination pattern; a number of image sensors, wherein an image sensor is arranged to detect light reflected from a scene irradiated by the irradiation pattern; and a processing unit realised to compute a depth map of the scene on the basis of a light pattern detected by an image sensor. The invention further describes an irradiation arrangement for use in such a depth map generator; a method of generating a depth map of a scene; and a device comprising such a depth map generator.
1. A depth map generator comprising:
an array comprising a plurality of individually addressable array elements, each of the plurality of individually addressable array elements comprising at least one of a semiconductor emitter or a reflector arranged to reflect light emitted by a semiconductor emitter;
a driver configured to switch the plurality of individually addressable array elements on or off according to a predefined illumination pattern, the predefined illumination pattern comprising a plurality of array elements that are switched on each bounded by at least two array elements that are switched off;
at least one image sensor configured to detect light reflected from a scene illuminated by the predefined illumination pattern; and
a processor configured to compute a depth map of the scene from the light pattern based on an offset between an expected position of a detected pixel in the light pattern and an actual position of the detected pixel in the light pattern.
2. The depth map generator according to claim 1 , wherein the semiconductor emitter is an infrared LED.
3. The depth map generator according to claim 1 , wherein the individually addressable array elements comprise semiconductor emitters and a primary optical element arranged to shape the light emitted by the semiconductor emitters of the array.
4. The depth map generator according to claim 1 , wherein the individually addressable array elements comprise reflectors, each of the reflectors being an individually addressable micro-mirror.
5. The depth map generator according to claim 1 , wherein the array comprises at least 100 individually addressable array elements.
6. The depth map generator according to claim 1 , wherein the image sensor comprises an array of photosensors sensitive to a wavelength of light originating from the array comprising the plurality of individually addressable array elements.
7. An illumination arrangement for use in a depth map generator, the illumination arrangement comprising:
an array of individually addressable array elements, each of the individually addressable array elements comprising at least one of a semiconductor emitter or a reflector arranged to reflect light emitted by a semiconductor emitter;
a driver configured to switch the plurality of individually addressable array elements on or off according to a predefined illumination pattern, the predefined illumination pattern comprising a plurality of array elements that are switched on each bounded by at least two array elements that are switched off;
at least one image sensor array configured to detect light reflected from a scene illuminated by the predetermined illumination pattern;
a processor configured to compute a depth map of the scene from the light pattern based on an offset between an expected position of a detected pixel in the light pattern and an actual position of the detected pixel in the light pattern;
a first interface configured to connect the driver to the depth map generator; and
a second interface configured to connect the processor to the depth map generator.
8. A method of generating a depth map of a scene, the method comprising:
arranging a depth map generator in front of the scene, the depth map generator including an array comprising a plurality of individually addressable array elements, each of the plurality of individually addressable array elements comprising at least one of a semiconductor emitter or a reflector arranged to reflect light emitted by a semiconductor emitter;
choosing an illumination pattern to illuminate the scene;
switching, via a driver, the plurality of individually addressable array elements of the array one or off according to the illumination pattern;
forming a light pattern from light reflected from the scene;
detecting, with at least one image sensor, the light pattern; and
computing a depth map of the scene from the light pattern based on an offset between an expected position of a detected pixel in the light pattern and an actual position of the detected pixel in the light pattern.
9. The method according to claim 8 , wherein the switching comprises switching the plurality of individually addressable array elements on or off according to a sequence of the illumination patterns.
10. The method according to claim 9 , wherein choosing the illumination pattern comprises choosing the sequence of the illumination patterns to successively illuminate the scene in at least one of a vertical direction and a horizontal direction.
11. The method according to claim 9 , wherein the sequence of the illumination patterns is the inverse of a preceding illumination pattern.
12. The method according to claim 8 , further comprising adjusting the illumination pattern on the basis of a computed depth map.
13. The depth map generator according to claim 1 , wherein the at least one image sensor comprises a single image sensor.
14. The illumination arrangement of claim 7 , wherein the at least one image sensor comprises a single image sensor.
15. The method of claim 8 , wherein the illumination pattern comprises a plurality of array elements that are switched on each bounded by at least two array elements that are switched off.