CALIBRATION METHOD FOR AN ELECTRONIC DISPLAY SCREEN FOR TOUCHLESS GESTURE CONTROL

Abstract

A computer-implemented method of calibrating an electronic display screen for touchless gesture control using a calibration device having a calibration pattern, wherein the method comprises: detecting, using at least one depth camera, the calibration pattern of the calibration device, the calibration device being placed on the electronic display screen in a calibration position; determining borders of the electronic display screen based at least on the detected calibration pattern, a reference pattern being usable for determining an orientation of the detected calibration pattern, and a screen dimension information with respect to the electronic display screen; defining a touchless gesture control input area for the electronic display screen being observable by the at least one depth camera.

Claims

1. A computer-implemented method of calibrating an electronic display screen for touchless gesture control using a calibration device having a calibration pattern, wherein the computer-implemented method comprises: detecting, using at least one depth camera, the calibration pattern of the calibration device while the calibration device is placed on the electronic display screen in a calibration position; determining borders of the electronic display screen based at least on the detected calibration pattern, a reference pattern which is usable for determining an orientation of the detected calibration pattern, and screen dimension information with respect to the electronic display screen; and defining a touchless gesture control input area for the electronic display screen being observable by the at least one depth camera.

2. The computer-implemented method of claim 1, further comprising: displaying a calibration guiding mark on the electronic display screen for guiding a user to place the calibration device in the calibration position.

3. The computer-implemented method of claim 2, wherein the calibration guiding mark comprises at least two markings being displayed on the electronic display screen.

4. The computer-implemented method according to claim 2, wherein the calibration guiding mark comprises at least one orientation reference marking for unequivocally guiding a user to place the calibration device on the electronic display screen in a specific rotational orientation with respect to a plane-normal of the electronic display screen.

5. The computer-implemented method of claim 1, wherein at least the steps of detecting the calibration pattern, determining borders of the electronic display screen and defining a touchless gesture control input area are triggered upon receiving a user input or upon automatically detecting that the calibration device is in the calibration position.

6. The computer-implemented method of claim 1, wherein determining borders of the electronic display screen comprises at least one base transformation operation of a coordinate system.

7. The computer-implemented method of claim 1, wherein determining borders of the electronic display screen comprises: determining, using the at least one depth camera, a center of the calibration pattern in 3D and defining a coordinate system, wherein the center of the calibration pattern is the origin of the coordinate system; and shifting the origin of the coordinate system orthogonal to the electronic display screen surface so that the origin of the coordinate system is in the plane of the electronic display screen surface.

8. The computer-implemented method of claim 1, wherein the screen dimension information with respect to the electronic display screen is received via user input and/or is determined automatically based on a resolution of the electronic display screen and based on a pixel density of the electronic display screen.

9. The computer-implemented method of claim 1, wherein detecting the calibration pattern of the calibration device is performed using two depth cameras; wherein the two depth cameras are arranged at borders of the electronic display screen.

10. The computer-implemented method of claim 1, wherein determining a touchless gesture control input area comprises a definition of a virtual screen layer being essentially parallel to the electronic display screen.

11. The computer-implemented method of claim 1, wherein the calibration pattern is a fiducial marker, and/or a three-dimensional pattern.

12. The computer-implemented method of claim 1, further comprising outputting a signal upon starting, successfully ending, aborting, and/or failing the calibration of the electronic display screen.

13. (canceled)

14. (canceled)

15. (canceled)

16. The computer-implemented method of claim 2, wherein the calibration guiding mark indicates a predetermined orientation of the calibration device with respect to the electronic display screen.

17. The computer-implemented method of claim 3, wherein the markings are visually distinguishable, in particular by means of different colors and/or shapes

18. The computer-implemented method of claim 5, wherein detecting that the calibration device is in the calibration position includes detecting a calibration triggering mark of the calibration device, wherein the calibration triggering mark may be an acoustic mark and/or a visual mark

19. The computer-implemented method of claim 9, wherein the two depth cameras are arranged at opposing borders of the electronic display screen.

20. The computer-implemented method of claim 10, wherein the virtual screen layers is at a distance to the electronic display screen.

21. A data processing apparatus configured to calibrate an electronic display screen for touchless gesture control using a calibration device, the data processing apparatus comprising: a processor; a memory communicatively connected to the processor; and computing instructions stored in the memory, that when executed by the processor, causes the processor to: detect, using the at least one depth camera, the calibration pattern of the calibration device while the calibration device is placed on the electronic display screen in a calibration position, determine borders of the electronic display screen based at least on the detected calibration pattern, a reference pattern which is usable for determining an orientation of the detected calibration pattern, and screen dimension information with respect to the electronic display screen, and define a touchless gesture control input area for the electronic display screen being observable by the at least one depth camera.

22. The data processing apparatus of claim 21, wherein the calibration device comprises: a main body defining a main axis of the calibration device; a footing at a distal end of the main body, the footing having at least one footing surface being placeable on the electronic display screen such that the footing surface is in contact with to the electronic display screen; and a calibration pattern comprising a machine-readable pattern being detectable by at least one depth camera, wherein the at least one depth camera is arranged at or near the electronic display screen and is configured to observe a spatial area in front of the electronic display screen in order to detect a gesture input of a user.

23. A tangible, non-transitory computer-readable medium storing instructions for calibrating an electronic display screen for touchless gesture control using a calibration device having a calibration pattern, the computing instructions when executed by a computing device, cause the computing device to: detect, using at least one depth camera, the calibration pattern of the calibration device while the calibration device is placed on the electronic display screen in a calibration position; determine borders of the electronic display screen based at least on the detected calibration pattern, a reference pattern which is usable for determining an orientation of the detected calibration pattern, and screen dimension information with respect to the electronic display screen; and define a touchless gesture control input area for the electronic display screen being observable by the at least one depth camera.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0083] The disclosure may be better understood by reference to the following drawings:

[0084] FIG. 1: A first schematic illustration of an electronic display screen according to embodiments of the present invention.

[0085] FIG. 2: A second schematic illustration of an electronic display screen according to embodiments of the present invention.

[0086] FIG. 3: A third schematic illustration of an electronic display screen according to embodiments of the present invention.

[0087] FIG. 4: A fourth schematic illustration of an electronic display screen according to embodiments of the present invention.

[0088] FIG. 5: A fifth schematic illustration of an electronic display screen according to embodiments of the present invention.

[0089] FIG. 6: A sixth schematic illustration of an electronic display screen according to embodiments of the present invention.

[0090] FIG. 7: A schematic illustration of an input area for gesture control according to embodiments of the present invention.

[0091] FIG. 8: A first schematic illustration of a calibration device according to embodiments of the present invention.

[0092] FIG. 9: A first schematic illustration of a calibration device according to embodiments of the present invention.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0093] FIG. 1 is a first schematic illustration of an electronic display screen 100. Two depth cameras 101 are mounted at edges of the electronic display screen 100, one at the upper edge and one at the lower edge. As the calibration process is in progress, the electronic display screen 100 displays a calibration guiding mark 102 in the center of the electronic display screen 100. The purpose of displaying the calibration guiding mark 102 is to guide a user to place a calibration device 200, in particular a footing surface 203, on the calibration guiding mark 102. Thus, the calibration device 200 can be placed in the correct calibration position on the electronic display screen 100. In that sense, the calibration guiding mark 102 defines predetermined position of the calibration device 200 on the electronic display screen 100.

[0094] Examples of the above-mentioned calibration device are illustrated in FIGS. 8 and 9. It may be provided that the calibration process is started upon receiving a user input or upon automatically detecting that the calibration device 200 is in the calibration position. Detecting that the calibration device 200 is in the calibration position may include detecting a calibration triggering mark 205 of the calibration device 200. The calibration triggering mark 205 may be a visual mark as can be seen in FIGS. 8 and 9. In other words, a calibration process may be configured to start automatically upon detection of the visual marking. Therefore, by providing the visual marking, an additional user input and/or triggering signal is not necessary and a calibration process may be triggered automatically based on the detection of the visual marking.

[0095] FIG. 2 is a second schematic illustration of an electronic display screen 100. Two depth cameras 101 are mounted at edges of the electronic display screen 100, one at the upper edge and one at the lower edge. As the calibration process is in progress, the electronic display screen 100 displays a calibration guiding mark 102 in the center of the electronic display screen 100 including an orientation reference marking 103. This unequivocally guides a user to a particular positioning of a calibration device 200 on the electronic display screen 100, in particularly to place the calibration device 200 on the electronic display screen 100 in a specific rotational orientation with respect to a plane-normal of the electronic display screen 100. The orientation reference marking 103 is provided at the edge of the displayed calibration guiding mark 102 in order to increase visibility while the calibration device 200 is placed on the calibration guiding mark 102.

[0096] For the calibration process, a respective calibration device 200, as illustrated in FIG. 9, may be used, having a corresponding orientation reference marking 206 on its footing surface 203. Thus, the user is supported to position calibration device correctly, in particular such that the respective orientation reference marking 206 and the respective displayed orientation reference marking 103 are at least partially overlapping. Providing an orientation reference marking will reduce the degrees of freedom in which the calibration device 200 may be placed on the electronic display screen 100 in an advantageous manner. The quality of a calibration process may therefore be enhanced.

[0097] FIG. 3 is a third schematic illustration of an electronic display screen 100. Two depth cameras 101 are mounted at edges of the electronic display screen 100, one at the upper edge and one at the lower edge. As the calibration process is in progress, the electronic display screen 100 displays a calibration guiding mark 102 comprising two markings 102a, 102b in the center of the electronic display screen 100. If a calibration device 200 having to footings 202 is used, the user is guided by the marking 102a, 102b to place each of the footings 202 on respective calibration guiding marks 102a, 102b.

[0098] For further decreasing the degrees of freedom that are available for placing the calibration device 200 on the electronic display screen 100, it is referred to the fourth schematic illustration of an electronic display screen 100 in FIG. 4. In this example, the markings 102a, 102b have different colors. Accordingly, a respective calibration device 200 may be used having footings 202 and/or footing surfaces 203 with different colors.

[0099] FIG. 5 illustrates a fifth embodiment of an electronic display screen 100 according to the present invention which displays three markings 102a, 102b, 102c. This decreases the risk of inaccuracies, e.g. resulting from positioning the calibration device 200 in a tilted manner. For further reducing the degrees of freedom, different colors may be used, as described above. An example with three markings 102a, 102b, 102c, the marking 102c having a different color, is illustrated in FIG. 6.

[0100] FIG. 7 illustrates the step of defining a touchless gesture control input area 104 for the electronic display screen 100 being observable by the at least one depth camera 101. For enabling gesture input, the input area 104 may include or be equal to a virtual screen layer 105 which is defined to extend distanced by a predetermined distanced parallel to the electronic display screen 100. In other words, the input area 104 may be a spatial area which is e.g. parallel to the screen layer and which is observed by the at least one depth camera 101 to recognize gesture inputs of users. Thus, it may be provided that determining a touchless gesture control input area comprises a definition of a virtual screen layer 105 being essentially parallel to the electronic display screen 100, preferably at a distance d.

[0101] In FIG. 8, a first schematic illustration of a calibration device 200 in accordance with embodiments of the present invention is shown. The calibration device 200 comprises a main body 201 along which a main axis M is defined. The main body 201 has a proximal end and a distal end. On the main body 201, a calibration triggering mark 205 is provided. Further, the calibration device 200 comprises a calibration pattern 204 which is schematically illustrated to be on the main body 201. Further, the calibration device 200 comprises a foot 202 having a footing surface 203. In FIG. 9, a second illustration of a calibration device 200 in accordance with embodiments of the present invention is shown. Compared to the calibration device 200 shown in FIG. 8, the calibration device of FIG. 9 further comprises a calibration reference marking 206 at its footing surface 203.

[0102] In the following, one embodiment of the present invention is described in different words. The person skilled in the art may understand and associate this wording in the context of the description above: [0103] a) guiding the user where to put the calibration device by showing a calibration guiding mark being a spot in the center of the screen [0104] aa) showing not only one single spot but 2-3 guiding marks or one with a reference marker to preserve the angle be straight [0105] b) the user aligns the calibration device with the guiding mark on the screen [0106] ba) after that, the user presses a button or any key to signal the calibration module that the thing is ready to be calibrated [0107] bb) or auto detect that the calibration device is placed by analyzing another small AprilTag which triggers calibration and which is shown only when the stick is placed on the screen [0108] c) detecting the center of the calibration pattern of the calibration device in 3D and the rotation of it in 3D [0109] ca) by already knowing the shape of the calibration pattern, the center and the corners of the calibration pattern can be found in 2D, for example an RGB or Infrared module of the depth camera [0110] cb) after that we need to transform 2D knowledge to 3D trough the other modules of the depth camera (adding depth information). To do that, we use the fact that Intel RealSense depth cameras which have two infrared sensors. The image disparity (difference in pixels of two particular images) is used to calculate the depth. So it is possible to get the depth of the center and the corners of the calibration pattern, and thus the 3D position of the calibration pattern. [0111] cc) after that, the angle of the calibration device may be calculated based on the 3D corner points of the calibration pattern [0112] cd) based on that, it is possible to figure out the relative positions and rotations of the depth camera [0113] ce) at this stage, the cameras positions in the marker coordinate space are known but after that we will transform camera positions to the screen coordinate space [0114] d) what is missing are the screen corners because all the other parts of calibration are already known at this stage [0115] da) to find the corners of the screen we need to know the screen width and height in cm or inch [0116] db) and just by adding the respective half of the width and the height to the center we know the corners [0117] dc) how to know the physical width and height of the screen? We can ask a user or take it from the system (in Windows OS we can take resolution multiplied by pixel density)

[0118] Although some aspects have been described in the context of an apparatus, it is clear that these aspects also represent a description of the corresponding method, where a block or device corresponds to a method step or a feature of a method step. Analogously, aspects described in the context of a method step also represent a description of a corresponding block or item or feature of a corresponding apparatus.

[0119] Some or all of the method steps may be executed by (or using) a hardware apparatus, such as a processor, a microprocessor, a programmable computer or an electronic circuit. Depending on certain implementation requirements, embodiments of the invention can be implemented in hardware or in software. The implementation can be performed using a non-transitory storage medium such as a digital storage medium, for example a floppy disc, a DVD, a Blu-Ray, a CD, a ROM, a PROM, and EPROM, an EEPROM or a FLASH memory, having electronically readable control signals stored thereon, which cooperate (or are capable of cooperating) with a programmable computer system such that the respective method is performed. Therefore, the digital storage medium may be computer readable.

[0120] Some embodiments of the invention provide a data carrier having electronically readable control signals, which are capable of cooperating with a programmable computer system, such that one of the methods described herein is performed.

[0121] Generally, embodiments of the invention can be implemented as a computer program (product) with a program code, the program code being operative for performing one of the methods when the computer program product runs on a computer. The program code may, for example, be stored on a machine-readable carrier. Other embodiments comprise the computer program for performing one of the methods described herein, stored on a machine-readable carrier. In other words, an embodiment of the present invention is, therefore, a computer program having a program code for performing one of the methods described herein, when the computer program runs on a computer.

[0122] A further embodiment of the invention provides a storage medium (or a data carrier, or a computer-readable medium) comprising, stored thereon, the computer program for performing one of the methods described herein when it is performed by a processor. The data carrier, the digital storage medium or the recorded medium are typically tangible and/or non-transitionary. A further embodiment of the present invention is an apparatus as described herein comprising a processor and the storage medium.

[0123] A further embodiment of the invention provides a data stream or a sequence of signals representing the computer program for performing one of the methods described herein. The data stream or the sequence of signals may, for example, be configured to be transferred via a data communication connection, for example, via the internet.

[0124] A further embodiment of the invention provides a processing means, for example, a computer or a programmable logic device, configured to, or adapted to, perform one of the methods described herein.

[0125] A further embodiment of the invention provides a computer having installed thereon the computer program for performing one of the methods described herein.

[0126] A further embodiment of the invention provides an apparatus or a system configured to transfer (e.g., electronically or optically) a computer program for performing one of the methods described herein to a receiver. The receiver may, for example, be a computer, a mobile device, a memory device or the like. The apparatus or system may, for example, comprise a file server for transferring the computer program to the receiver.

[0127] In some embodiments, a programmable logic device (for example, a field programmable gate array) may be used to perform some or all of the functionalities of the methods described herein. In some embodiments, a field programmable gate array may cooperate with a microprocessor in order to perform one of the methods described herein. Generally, the methods are preferably performed by any hardware apparatus.

[0128] The below Reference Signs are provided herein by way of non-limiting example.

REFERENCE SIGNS

[0129] 100 electronic display screen [0130] 101 depth camera [0131] 102 calibration guiding mark [0132] 102a marking [0133] 102b marking [0134] 102c marking [0135] 103 calibration reference marking [0136] 104 input area [0137] 105 virtual screen layer [0138] d distance [0139] 200 calibration device [0140] 201 main body [0141] M main axis [0142] 202 footing [0143] 203 footing surface [0144] 204 calibration pattern [0145] 205 calibration triggering mark [0146] 206 orientation reference marking

ASPECTS OF THE PRESENT DISCLOSURE

[0147] The following aspects of the disclosure are exemplary only and not intended to limit the scope of the disclosure. [0148] 1. A computer-implemented method of calibrating an electronic display screen (100) for touchless gesture control using a calibration device (200) having a calibration pattern (204), wherein the method comprises: [0149] detecting, using at least one depth camera (101), the calibration pattern (204) of the calibration device (200) while the calibration device (200) is placed on the electronic display screen (100) in a calibration position; [0150] determining borders of the electronic display screen (100) based at least on the detected calibration pattern (204), a reference pattern which is usable for determining an orientation of the detected calibration pattern (204), and screen dimension information with respect to the electronic display screen (100); and [0151] defining a touchless gesture control input area (104) for the electronic display screen (100) being observable by the at least one depth camera (101). [0152] 2. The method of aspect 1, further comprising: [0153] displaying a calibration guiding mark (102) on the electronic display screen (100), preferably in or near the center of the electronic display screen (100), for guiding a user to place the calibration device (200) in the calibration position; and [0154] wherein, optionally, the calibration guiding mark (102) indicates a predetermined orientation of the calibration device (200) with respect to the electronic display screen (100). [0155] 3. The method of aspect 2, wherein the calibration guiding mark (102) comprises at least two, preferably three, markings (102a, 102b, 102c) being displayed on the electronic display screen (100); [0156] wherein, optionally, the markings (102a, 102b, 102c) are visually distinguishable, in particular by means of different colors and/or shapes. [0157] 4. The method according to aspect 2 or 3, wherein the calibration guiding mark (102) comprises at least one orientation reference marking (103) for unequivocally guiding a user to place the calibration device (200) on the electronic display screen (100) in a specific rotational orientation with respect to a plane-normal of the electronic display screen (100). [0158] 5. The method of any one of the preceding aspects, wherein at least the steps of detecting the calibration pattern (204), determining borders of the electronic display screen (100) and defining a touchless gesture control input area (104) are triggered upon receiving a user input or upon automatically detecting that the calibration device (200) is in the calibration position; [0159] wherein, optionally, detecting that the calibration device (200) is in the calibration position includes detecting a calibration triggering mark (205) of the calibration device (200), wherein the calibration triggering mark (205) may be an acoustic mark and/or a visual mark. [0160] 6. The method of any one of the preceding aspects, wherein determining borders of the electronic display screen (100) comprises at least one base transformation operation of a coordinate system. [0161] 7. The method of any one of the preceding aspects, wherein determining borders of the electronic display screen (100) comprises: [0162] determining, using the at least one depth camera (101), a center of the calibration pattern (204) in 3D and defining a coordinate system, wherein the center of the calibration pattern (204) is the origin of the coordinate system; and [0163] shifting the origin of the coordinate system orthogonal to the electronic display screen (100) surface so that the origin of the coordinate system is in the plane of the electronic display screen (100) surface. [0164] 8. The method of any one of the preceding aspects, wherein the screen dimension information with respect to the electronic display screen (100) is received via user input and/or is determined automatically based on a resolution of the electronic display screen (100) and based on a pixel density of the electronic display screen. [0165] 9. The method of any one of the preceding aspects, wherein detecting the calibration pattern (204) of the calibration device (200) is performed using two depth cameras (101); [0166] wherein the two depth cameras (101) are arranged at, preferably opposing, borders of the electronic display screen (100). [0167] 10. The method of any one of the preceding aspects, wherein determining a touchless gesture control input area (104) comprises a definition of a virtual screen layer (105) being essentially parallel to the electronic display screen (100), preferably at a distance (d). [0168] 11. The method of any one of the preceding aspects, wherein the calibration pattern (204) is a fiducial marker, preferably an AprilTag and/or a QR-Code, and/or a three-dimensional pattern, preferably having a spherical shape. [0169] 12. The method of any one of the preceding aspects, further comprising outputting a signal upon starting, successfully ending, aborting, and/or failing the calibration of the electronic display screen (100). [0170] 13. A calibration device (200) for use in the method according to any one of aspects 1 to 12 for calibrating an electronic display screen (100), comprising: [0171] a main body (201) defining a main axis (M) of the calibration device (100); [0172] a footing (202) at a distal end of the main body (201), the footing (202) having at least one footing surface (204) being placeable on the electronic display screen (100) such that the footing surface (204) is in contact with to the electronic display screen (100); and [0173] a calibration pattern (204) comprising a machine-readable pattern being detectable by at least one depth camera (101), wherein the at least one depth camera (101) is arranged at or near the electronic display screen (100) and is configured to observe a spatial area in front of the electronic display screen (100) in order to detect a gesture input of a user. [0174] 14. A data processing apparatus, preferably an electronic display screen (100), comprising means for carrying out the method of any one of aspects 1 to 12. [0175] 15. A computer program comprising instructions which, when the program is executed by a computer, cause the computer to carry out the method of any one of aspects 1 to 12.