PROJECTION CAPTURE SYSTEM AND METHOD
In one example, a projection capture system includes: a digital camera, a projector, and a mirror housed together as a single unit in which, when the unit is deployed for use with a work surface: the camera is positioned above the projector; the projector is positioned below the camera; and the mirror is positioned above the projector and configured to reflect light from the projector into the camera capture area. In one example, a projection capture method includes: establishing a camera capture area within which a camera can capture an image of an object; establishing a projector display area overlapping the capture area and into which a projector can project light; lighting the camera capture area with the projector; and positioning a specular glare spot from the projector lighting outside the camera capture area.
A new projection capture system has been developed in an effort to improve digitally capturing images of documents and other objects and in an effort to improve the interactive user experience working with real objects and projected objects on a physical work surface.
The same part numbers are used to designate the same or similar parts throughout the figures,
DESCRIPTIONThe examples shown in the figures and described below illustrate but do not limit the invention, which is defined in the Claims following this Description.
In one example of the new projection capture system, a digital camera, a projector, and a mirror are housed together as a single unit in which, when the unit is deployed for use with a work surface, the camera is positioned above the projector, the projector is positioned below the camera, and the mirror is positioned above the projector and configured to reflect light from the projector into the camera capture area. In one example, the projector provides a light source for the camera capturing images where the camera, the projector, and the mirror are positioned with respect to one another such that the glare spot from the projector light lies outside the camera capture area.
In the example shown in
System 10 also includes a user input device 26 that allows the user to interact with system 10. A user may interact with object 20 and/or object image 22 in workspace 12 through input device 26, object image 22 transmitted to other workspaces 12 on remote systems 10 (not shown) for collaborative user interaction, and, if desired, object image 22 maybe photographed by camera 14 and re-projected into local and/or remote workspaces 12 for further user interaction. In
In the example shown in
In one example implementation for system 10, projector 16 serves as the light source for camera 14. Camera capture area 32 (
Ideally, projector 16 would be mounted directly over workspace 12 at an infinite height above work surface 24 to insure parallel light rays. This configuration, of course, is not realistic. Even if projector 16 was moved down to a realistic height above work surface 24 (but still pointing straight down), the projector's light would be reflected off glossy and semi-glossy surfaces and objects straight back into camera 14, creating a blinding specular glare. Thus, the glare spot must be moved out of camera capture area 32. (Specular glare refers to glare from specular reflection in which the angle of incidence of the incident light ray and the angle of reflection of the reflected light ray are equal and the incident, reflected, and normal directions are coplanar.)
To achieve a commercially reasonable solution to this problem of specular glare, camera 14 and projector 16 are shifted away from the center of capture and display areas 32, 34 and projector 16 is positioned low, near base 36, as shown in
In
Moving camera 14 off center over capture area 32 brings projector 16 in to make the system less broad, as shown in
As shown in
Thus, and referring again to
Referring now to
Referring now also to
Referring to
One example of suitable characteristics for system 10 as a standalone device 40 are set out in Table 1. (Dimension references in Table 1 are to
Since projector 16 acts as the light source for camera 12 for still and video capture, the projector light must be bright enough to swamp out any ambient light that might cause defects from specular glare. It has been determined that a projector light 200 lumens or greater will be sufficiently bright to swamp out ambient light for the typical desktop application for system 10 and device 40. For video capture and real-time video collaboration, projector 16 shines white light into workspace 12 to illuminate object(s) 20. For an LED projector 16, the time sequencing of the red, green, and blue LED's that make up the white light are synchronized with the video frame rate of camera 14. The refresh rate of projector 16 and each LED sub-frame refresh period should be an integral number of the camera's exposure time for each captured frame to avoid “rainbow banding” and other unwanted effects in the video image. Also, the camera's video frame rate should be synchronized with the frequency of any ambient fluorescent lighting that typically flickers at twice the AC line frequency (e.g., 120 Hz for a 60 Hz AC power line). An ambient light sensor can be used to sense the ambient light frequency and adjust the video frame rate for camera 14 accordingly. For still image capture, the projector's red, green, and blue LED's can be turned on simultaneously for the camera flash to increase light brightness in workspace 12, helping swamp out ambient light and allowing faster shutter speeds and/or smaller apertures to reduce noise in the image.
The example configuration for system 10 integrated into a standalone device 40 shown in the figures and described above achieves a desirable balance among product size, performance, usability, and cost. The folded light path for projector 16 reduces the height of device 40 while maintaining an effective placement of the projector high above workspace 12 to prevent specular glare in the capture area of camera 12. The projector's light path shines on a horizontal work surface 24 at a steep angle enabling 3D object image capture. This combination of a longer light path and steep angle minimizes the light fall off across the capture area to maximize the light uniformity for camera flash. In addition, the folded light path enables the placement of projector 16 near base 36 for product stability.
Suitable input devices and techniques for use in system 10 include, for example, finger touch, touch gestures, stylus, in-air gestures, voice recognition, head tracking and eye tracking. A touch pad can be used to enable a multi-touch interface for navigating a graphical user interface or performing intuitive gesture actions like push, flick, swipe, scroll, pinch-to-zoom, and two-finger-rotate. Depth cameras using structured light, time-of-flight, disturbed light pattern, or stereoscopic vision might also be used to enable in-air gesturing or limited touch and touch gesture detection without a touch pad. A touch-free digital stylus is particularly well suited as a user input 26 for system 10. Thus, in the example shown in the figures, user input 26 includes an infrared digital stylus 28 and an infrared camera 30 for detecting stylus 28 in workspace 12. As noted above, a touch-free digital stylus has the advantage of allowing input in three dimensions, including along work surface 24, without a sensing pad or other special surface.
Referring now to
Nib switch 58 may be touch sensitive to about 2 gr of force, for example, to simulate a traditional writing instrument. When the stylus's nib touches work surface 24 or another object, nib switch 58 detects the contact and turns on light 56. Light 56 turning on is detected by camera 30 which signals a touch contact event (similar to a mouse button click or a finger touch on a touch pad). Camera 30 continues to signal contact, tracking any movement of stylus 28, as long as light 56 stays on. The user can slide stylus 28 around on any surface like a pen to trace the surface or to activate control functions. When the stylus nib is no longer in contact with an object, light 56 is switched off and camera 30 signals no contact. Manual light switch 60 may be used to signal a non-touching event. For example, when working in a three dimensional workspace 12 the user may wish to modify, alter, or otherwise manipulate a projected image above work surface 24 by manually signaling a “virtual” contact event.
Infrared camera 30 and mirror 38 define a three dimensional infrared capture space 61 in workspace 12 within which infrared camera 30 can effectively detect light from stylus 28. Capture space 61 is bounded in the X and Y dimensions by an infrared camera capture area 62 on work surface 24. In the example shown, as best seen by comparing
In one example implementation shown in
It may be desirable for some commercial implementations to house projector 16 and infrared camera 30 together in a single housing 82 as shown in
Although it is expected that workspace 12 usually will include a physical work surface 24 for supporting an object 20, work space 12 could also be implemented as a wholly projected work space without a physical work surface. In addition, workspace 12 may be implemented as a three dimensional workspace for working with two and three dimensional objects or as a two dimensional workspace for working with only two dimensional objects. While the configuration of workspace 12 usually will be determined largely by the hardware and programming elements of system 10, the configuration of workspace 12 can also be affected by the characteristics of a physical work surface 24. Thus, in some examples for system 10 and device 40 it may be appropriate to consider that workspace 12 is part of system 10 in the sense that the virtual workspace accompanies system 10 to be manifested in a physical workspace when device 36 is operational, and in other examples it may be appropriate to consider that workspace 12 is not part of system 10.
The system 10 examples shown in the figures, with one camera 14 and one projector 16, do not preclude the use of two or more cameras 14 and/or two or more projectors 16. Indeed, it may be desirable in some applications for a system 10 to include more than one camera, more than one projector or more than one of other system components. Thus, the articles “a” and “an” as used in this document mean one or more.
As noted at the beginning of this Description, the examples shown in the figures and described above illustrate but do not limit the invention. Other examples, embodiments and implementations are possible. Therefore, the foregoing description should not be construed to limit the scope of the invention, which is defined in the following claims.
Claims
1. A projection capture system for use with a work surface, the system comprising:
- a digital camera, a projector, and a mirror housed together as a single unit in which, when the unit is deployed for use with the work surface: the camera is positioned above the projector and the camera defines a capture area within which the camera can acquire images on the work surface; the projector is positioned below the camera; and the mirror is positioned above the projector and configured to reflect light from the projector down on to the work surface, and the projector and the mirror define a display area on the work surface overlapping at least part of the capture area.
2. The system of claim 1, wherein:
- the camera and the projector are operatively connected to one another such that the projector provides a light source for the camera capturing images; and
- the camera, the projector, and the mirror are positioned with respect to one another such that, when the unit is deployed for use with the work surface, a glare spot from projector light reflected off the mirror lies outside the camera capture area.
3. The system of claim 2, wherein, when the unit is deployed for use with the work surface:
- the camera is positioned over the capture area at a location offset from a center of the capture area; and
- the projector is positioned outside the capture area and outside the display area.
4. The system of claim 2, further comprising a controller housed together with the digital camera, the projector, and the mirror as part of the single unit, the controller operatively connecting the camera and the projector and configured to control the camera and the projector for:
- capturing an image of an object positioned on the work surface in the capture area; and
- projecting the object image onto the work surface in the display area.
5. The system of claim 4, further comprising a user input device operatively connected to the controller and configured to enable a user to interact with the system on the work surface.
6. The system of claim 5, wherein the unit is configured for deployment with a flat, horizontal work surface.
7. The system of claim 6, further comprising a portable mat deployable with the unit as the work surface.
8. The system of claim 2, wherein the display area and the capture area are substantially the same.
9. A projection capture system for use with a work surface, the system comprising:
- a digital camera, a projector, a controller and a mirror housed together as a single unit in which, when the unit is deployed for use with the work surface: the camera defines a capture area within which the camera can acquire images on the work surface; and the projector and the mirror define a display area on the work surface overlapping at least part of the capture area; and
- the controller operatively connecting the camera and the projector and configured to control the camera and the projector for: the projector illuminating the capture area; the camera capturing an image of an object positioned on the work surface in the capture area and illuminated by the projector; and the projector projecting the object image onto the work surface in the display area.
10. The system of claim 9, the camera, the projector, and the mirror are positioned with respect to one another such that, when the unit is deployed for use with the work surface, a glare spot from projector light reflected off the mirror lies outside the camera capture area.
11. The system of claim 9, further comprising a user input device operatively connected to the controller and configured to enable a user to interact with the system on the work surface.
12. An interactive projection capture system for use with a three dimensional workspace having a horizontal work surface, the system comprising:
- a digital camera, a projector, and a mirror housed together as a single unit in which, when the unit is deployed for use with the workspace: the camera defines a three dimensional capture space within which the camera can effectively acquire images, the capture space bounded in two dimensions by a capture area on the work surface; the projector and the mirror define a three dimensional display space bounded in two dimensions by a display area on the work surface overlapping at least part of the capture area; and the camera, the projector, and the mirror are positioned with respect to one another such that light from the projector reflected off the mirror illuminates the capture space and a glare spot from the reflected light lies outside the capture space; and
- a user input device operatively connected to the camera and the projector and configured to enable a user to interact with the system in the workspace.
13. The system of claim 12, further comprising a controller operatively connecting the camera and the projector and configured to control the camera and the projector for:
- the projector illuminating the capture space;
- the camera capturing an image of an object positioned on the work surface in the capture area and illuminated by the projector;
- the projector projecting the object image onto the work surface in the display area; and
- the camera capturing an image of the projected object image.
14. The system of claim 12, wherein the user input device includes an infrared digital stylus for selectively emitting infrared light within the workspace and an infrared camera for capturing infrared light emitted by the stylus within the workspace.
15. The system of claim 14, wherein a capture space of the infrared camera is coincident with the display space.
16. A projection capture method, comprising:
- establishing a camera capture area within which a camera can capture an image of an object;
- establishing a projector display area overlapping the capture area and into which a projector can project light;
- lighting the camera capture area with the projector; and
- positioning a specular glare spot from the projector lighting outside the camera capture area.
17. The method of claim 16, wherein positioning the specular glare spot outside the camera capture area includes the projector projecting light up toward a mirror and the mirror reflecting light down into the camera capture area.
18. The method of claim 16, wherein positioning the specular glare spot outside the camera capture area includes folding a light path from the projector to the camera capture area along a fold line.
19. The method of claim 18, wherein the fold line is defined by a light reflecting surface.
Type: Application
Filed: Aug 2, 2011
Publication Date: May 22, 2014
Inventor: David Bradley Short (San Diego, CA)
Application Number: 14/234,030
International Classification: H04N 7/18 (20060101);