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Title:
SELECTING FOCUSING AREA BY GAZE DIRECTION
Document Type and Number:
WIPO Patent Application WO/2008/040575
Kind Code:
A1
Abstract:
The invention discloses a method and a portable device for focusing an image in the device (10), which device (10) comprises; a first image recording arrangement (24a) for recording images or video sequences of an user (50) of the device (10); a second image recording arrangement (24b) comprising an autofocus arrangement for recording images or video sequences of the environment surrounding the device (10); and a display arrangement (22) for reproducing the recorded images or video sequences of the environment surrounding the device (10), which method comprises the step of: recording an image or video sequence of the environment by the second image recording arrangement (24b); obtaining a gazing direction of the user (50) from images or video sequences recorded by the first image recording arrangement (24a); selecting a focusing area in the image or video sequence reproduced by the display (22), depending on the obtained gazing direction; focusing the recorded image or video sequence of the environment surrounding the device (10) by means of the autofocus arrangement so that the object or objects within the focusing area becomes sharp.

Inventors:
GRIP MARTIN (SE)
THOERN OLA (SE)
Application Number:
PCT/EP2007/056307
Publication Date:
April 10, 2008
Filing Date:
June 25, 2007
Export Citation:
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Assignee:
SONY ERICSSON MOBILE COMM AB (SE)
GRIP MARTIN (SE)
THOERN OLA (SE)
International Classes:
H04N5/232
Foreign References:
US6191819B12001-02-20
US20050073136A12005-04-07
Attorney, Agent or Firm:
VALEA AB (Göteborg, SE)
Download PDF:
Claims:

CLAIMS

1. A method for focusing an image or a video sequence in a portable device (10), which device (10) comprises; - a first image recording arrangement (24a) for recording images or video sequences of an user (50) of the device (10);

- a second image recording arrangement (24b) comprising an autofocus arrangement for recording images or video sequences of the environment surrounding the device (10); and - a display arrangement (22) for reproducing the recorded images or video sequences of the environment surrounding the device (10), which method comprises the step of:

- recording an image or video sequence of the environment by the second image recording arrangement (24b); - obtaining a gazing direction of the user (50) from images or video sequences recorded by the first image recording arrangement (24a);

- selecting a focusing area in the image or video sequence reproduced by the display (22), depending on the obtained gazing direction;

- focusing the recorded image or video sequence of the environment surrounding the device (10) by means of the autofocus arrangement so that the object or objects within the focusing area becomes sharp.

2. A method according to claim 1 characterized by; obtaining a gazing direction towards the environment surrounding the device (10) and/or towards the display arrangement (22).

3. A method according to claim 1 characterized by; obtaining a gazing direction for the face of the user (50) and/or at least one eye of the user (50).

4. A method according to claim 3 characterized by; selecting a focusing area depending on the obtained gazing directions for both the face and said at least one eye of the user (50).

5. A method according to claim 1 characterized by; selecting a focusing area in a focusing grid (700) of focusing areas or moving a movable focusing frame (400), depending on the obtained gazing direction so as to select a focusing area.

6. A method according to claim 5 characterized by; changing the shape of the focusing grid (700) or the focusing frame (400) on commands from the user (50).

7. A method according to any of claim 5 or 6 wherein; the focusing grid (700) or focusing frame (400) is visible to the user (50).

8. A method according to claim 1 wherein; the portable device (10) is a portable communication device.

9. A method according to claim 1 wherein; the first imaging arrangement (24a) is recording images or video sequences of the user (50) in a first operational mode for obtaining a gazing direction of the user (50) and in a second operational mode for providing images or video sequences of the user (50) during a video-call.

10. A method according to claim 9 wherein; the portable communication device is a cell phone (10).

1 1. A portable device (10) comprising;

- a first image recording arrangement (24a) for recording images or video sequences of an user (50) of the device (10); - a second image recording arrangement (24b) comprising an autofocus arrangement for recording images or video sequences of the environment surrounding the device (10); a display arrangement (22) for reproducing the recorded images or video sequences of the environment surrounding the device (10); and - an autofocus-control (40) for focusing an image or a video sequence in the device

(10), characterized in that the autofocus-control (40) is arranged to operatively. obtain a gazing direction of the user (50) from images or video sequences recorded by the first image recording arrangement (24a);

- select a focusing area in the image or video sequence reproduced by the display (22), depending on the obtained gazing direction;

- focus the recorded image or video sequence of the environment surrounding the device (10) by means of the autofocus arrangement so that the object or objects within the focusing area becomes sharp.

12. A portable device (10) according to claim 1 1 characterized in that the autofocus- control (40) is arranged to operatively obtain a gazing direction towards the environment surrounding the device (10) and/or towards the display arrangement (22).

13. A portable device (10) according to claim 11 characterized in that the autofocus- control (40) is arranged to operatively obtain a gazing direction for the face of the user (50) and/or at least one eye of the user (50).

14. A portable device (10) according to claim 13 characterized in that the autofocus- control (40) is arranged to operatively select a focusing area depending on the obtained gazing direction for both the face and said at least one eye of the user (50).

15. A portable device (10) according to claim 1 1 characterized in that the autofocus- control (40) is arranged to operatively select a focusing area in a grid of focusing areas or to move a movable focusing frame (400), depending on the obtained gazing direction so as to identify a focusing area.

16. A portable device (10) according to claim 15 characterized in that the autofocus- control (40) is arranged to operatively change the shape of the focusing grid (700) or the focusing frame (400) on commands from the user (50).

17. A portable device (10) according to any of claim 15 or 16 characterized in that the focusing grid (700) or focusing frame (400) is visible to the user (50).

18. A portable device (10) according to claim 11 characterized in that the portable device (10) is a portable communication device.

19. A portable device (10) according to claim 1 1 characterized in that the first imaging arrangement (24a) is arranged to operatively record images or video sequences of the user (50) in a first operational mode for obtaining a gazing direction of the user (50), and arranged to operatively record images or video sequences of the user (50) in a second mode for providing images or video sequences of the user (50) during a video-call.

20. A portable device according to claim 18 characterized in that the portable communication device is a cell phone.

21. A computer program product stored on a computer usable medium, comprising readable program means for causing a portable device (10) to execute, when said program means is loaded in the portable device (10) comprising: a first image recording arrangement (24a) for recording images or video sequences of an user (50) of the device (10);

- a second image recording arrangement (24b) comprising an autofocus arrangement for recording images or video sequences of the environment surrounding the device (10);

- a display arrangement (22) for reproducing the recorded images or video sequences of the environment surrounding the device (10); and an autofocus-control (40) for focusing an image or a video sequence in the device (10), the steps of: recording an image of the environment by the second image recording arrangement (24b); obtaining a gazing direction of the user (50) from images or video sequences recorded by the first image recording arrangement (24a);

- selecting a focusing area in the image or video sequence reproduced by the display (22), depending on the obtained gazing direction; - focusing the recorded image or video sequence of the environment surrounding the device (10) by means of the autofocus arrangement so that the object or objects within the focusing area becomes sharp.

22. A computer program element having a program recorded thereon, where the program is to make a portable device (10) to execute, when said program means is loaded in the portable device (10) comprising:

- a first image recording arrangement (24a) for recording images or video sequences of an user (50) of the device (10);

- a second image recording arrangement (24b) comprising an autofocus arrangement for recording images or video sequences of the environment surrounding the device (10);

- a display arrangement (22) for reproducing the recorded images or video sequences of the environment surrounding the device (10); and

- an autofocus-control (40) for focusing an image or a video sequence in the device (10), the steps of:

- recording an image of the environment by the second image recording arrangement (24b);

- obtaining a gazing direction of the user (50) from images or video sequences recorded by the first image recording arrangement (24a);

- selecting a focusing area in the image or video sequence reproduced by the display (22), depending on the obtained gazing direction; - focusing the recorded image or video sequence of the environment surrounding the device (10) by means of the autofocus arrangement so that the object or objects within the focusing area becomes sharp.

Description:

SELECTING FOCUSING AREA BY GAZE DIRECTION

TECHNICAL FIELD OF THE INVENTION

The present invention relates to the field of portable devices comprising an imaging system. In particular the present invention relates to a method and an arrangement for selecting a focusing area in an image in an imaging system.

DESCRIPTION OF RELATED ART

It is well known to those skilled in the art of portable imaging devices that the correct focus of an image can be obtained by means of a so-called autofocus arrangement. The speed and accuracy of autofocusing arrangements are for the most Digital Still Camera (DSC) purposes superior to a manual adjustment of the image focus.

Autofocus arrangements are typically based on either an active system or a passive system. An active system is usually operating in two steps. In a first step a distance measuring (e.g. based on ultrasonic sound waves or infrared light or similar) is performed separated from the optical system. In a second step a focus adjustment of the optical system is performed based on the measured distance. As a contrast, passive systems do not rely on transmissions or similar (e.g. in form of electromagnetic rays or sound waves etc) from the camera towards the object to be recorded. Instead, these systems utilize the light that is naturally reflected by the object. A passive autofocusing can be achieved by e.g. phase detection or contrast measurement as is well known in the art.

However, since the whole image cannot be focused at the same time the part in the image that is to be focused has to be determined. For this purpose, known autofocus systems are utilizing a viewfinder provided with a focusing frame or similar that has to be aimed at the object on which the image is to be focused. If the focus frame is aimed otherwise there is no guarantee that the desired object will be in focus in the recorded image. However, since the focus frame is typically arranged in the center of the viewfinder it is difficult to focus the image on an object that is located outside the image center, i.e. located in the periphery of the image.

To remedy this some viewfinders are provided with a plurality of focusing frames to choose from. The focus of the image can e.g. be set in the middle, at the right side, at the left side, at the top or at the bottom etc. However, only one setting can be chosen. The setting is often chosen automatically and the focus is typically set on the object closest to the camera in the focusing area.

In view of the above it would be beneficial to provide the user of a portable imaging device with a more efficient and flexible procedure for focusing an image at a desired depth. In particular, it would be beneficial to provide a simple, flexible and intuitive focusing. Even more particularly, it would be beneficial to provide such an improved focusing without having to add auxiliary hardware for accomplishing the improvement.

SUMMARY OF THE INVENTION

The present invention is directed to solving the problem of providing a user of a portable imaging device with an efficient and flexible procedure for focusing an image at a desired focusing area. In particular, the present invention is intended to solve the problem of providing a simple, flexible and intuitive focusing procedure.

At least one of the problems identified above is solved according to a first aspect of the invention which provides a method for focusing an image or a video sequence in a portable device, which device comprises; a first image recording arrangement for recording images or video sequences of an user of the device; a second image recording arrangement comprising an autofocus arrangement for recording images or video sequences of the environment surrounding the device; and a display arrangement for reproducing the recorded images or video sequences of the environment surrounding the device,

The method comprises the step of: - recording an image or video sequence of the environment by the second image recording arrangement;

- obtaining a gazing direction of the user from images or video sequences recorded by the first image recording arrangement; selecting a focusing area in the image or video sequence reproduced by the display, depending on the obtained gazing direction;

- focusing the recorded image or video sequence of the environment surrounding the device by means of the autofocus arrangement so that the object or objects within the focusing area becomes sharp.

A second aspect of the invention directed to a method comprising the features of the first aspect is characterized by obtaining a gazing direction towards the environment surrounding the device and/or the display of the device.

A third aspect of the invention directed to a method comprising the features of the first aspect is characterized by obtaining a gazing direction for the face of the user and/or at least one eye of the user.

A fourth aspect of the invention directed to a method comprising the features of the third aspect is characterized by selecting a focusing area depending on the obtained gazing directions for both the face and said at least one eye of the user.

A fifth aspect of the invention directed to a method comprising the features of the first aspect is characterized by selecting a focusing area in a focusing grid of focusing areas or by moving a movable focusing frame, depending on the obtained gazing direction so as to select a focusing area.

A sixth aspect of the invention directed to a method comprising the features of the fifth aspect is characterized by changing the shape of the focusing grid or focusing frame on commands from the user.

A seventh aspect of the invention directed to a method comprising the features of the fifth aspect or the sixth aspect and wherein the focusing grid or focusing frame is visible to the user.

An eight aspect of the invention directed to a method comprising the features of the first aspect and wherein the portable device is a portable communication device.

A ninth aspect of the invention directed to a method comprising the features of the first aspect and wherein the first imaging arrangement is recording images or video sequences

of the user in a first operational mode for obtaining a gazing direction of the user and in a second mode for providing images or video sequences of the user during a video-call.

A tenth aspect of the invention directed to a method comprising the features of the ninth aspect and wherein the portable communication device is a cell phone.

Moreover, at least one of the problems identified above is solved according to an eleventh aspect of the invention which provides a portable device comprising; a first image recording arrangement for recording images or video sequences of an user of the device; a second image recording arrangement comprising an autofocus arrangement for recording images or video sequences of the environment surrounding the device; a display arrangement for reproducing the recorded images or video sequences of the environment surrounding the device; and an autofocus-control for focusing an image or a video sequence in the device.

The portable device is characterized in that the autofocus-control is arranged to operatively: obtain a gazing direction of the user from images or video sequences recorded by the first image recording arrangement; select a focusing area in the image or video sequence reproduced by the display, depending on the obtained gazing direction; focus the recorded image or video sequence of the environment surrounding the device by means of the autofocus arrangement so that the object or objects within the focusing area becomes sharp.

A twelfth aspect of the invention directed to a device comprising the features of the eleventh aspect is characterized in that the autofocus-control is arranged to operatively obtain a gazing direction towards the environment surrounding the device.

A thirteenth aspect of the invention directed to a device comprising the features of the eleventh aspect is characterized in that the autofocus-control is arranged to operatively obtain a gazing direction for the face of the user and/or at least one eye of the user.

A fourteenth aspect of the invention directed to a device comprising the features of the thirteenth aspect is characterized in that the autofocus-control is arranged to operatively select a focusing area depending on the obtained gazing direction for both the face and said at least one eye of the user.

A fifteenth aspect of the invention directed to a device comprising the features of the eleventh aspect is characterized in that the autofocus-control is arranged to operatively select a focusing area in a grid of focusing areas or to move a movable focusing frame, depending on the obtained gazing direction so as to identify a focusing area.

A sixteenth aspect of the invention directed to a device comprising the features of the fifteenth aspect is characterized in that the autofocus-control is arranged to operatively change the shape of the focusing grid or focusing frame on commands from the user.

A seventeenth aspect of the invention directed to a device comprising the features of any of the fifteenth aspect or the sixteenth aspect is characterized in that the focusing grid or focusing frame is visible to the user.

An eighteenth aspect of the invention directed to a device comprising the features of the eleventh aspect is characterized in that the portable device is a portable communication device.

A nineteenth aspect of the invention directed to a device comprising the features of the eleventh aspect is characterized in that the first imaging arrangement is arranged to operatively record images or video sequences of the user in a first operational mode for obtaining a gazing direction of the user, and arranged to operatively record images or video sequences of the user in a second mode for providing images or video sequences of the user during a video-call.

A twentieth aspect of the invention directed to a device comprising the features of the nineteenth aspect is characterized in that the portable communication device is a cell phone.

A twenty-first aspect of the invention is directed to computer program product stored on a computer usable medium, comprising readable program means for causing a portable device to execute, when said program means is loaded in the portable device comprising: a first image recording arrangement for recording images or video sequences of an user of the device; a second image recording arrangement comprising an autofocus arrangement for recording images or video sequences of the environment surrounding the

device; a display arrangement for reproducing the recorded images or video sequences of the environment surrounding the device; and an autofocus-control for focusing an image or a video sequence in the device, the steps of: - recording an image of the environment by the second image recording arrangement;

- obtaining a gazing direction of the user from images or video sequences recorded by the first image recording arrangement;

- selecting a focusing area in the image or video sequence reproduced by the display, depending on the obtained gazing direction; - focusing the recorded image or video sequence of the environment surrounding the device by means of the autofocus arrangement so that the object or objects within the focusing area becomes sharp.

A twenty-second aspect of the invention is directed to a computer program element having a program recorded thereon, where the program is to make a portable device to execute, when said program means is loaded in the portable device comprising: a first image recording arrangement for recording images or video sequences of an user of the device; a second image recording arrangement comprising an autofocus arrangement for recording images or video sequences of the environment surrounding the device; a display arrangement for reproducing the recorded images or video sequences of the environment surrounding the device; and an autofocus-control for focusing an image or a video sequence in the device, the steps of:

- recording an image of the environment by the second image recording arrangement; - obtaining a gazing direction of the user from images or video sequences recorded by the first image recording arrangement;

- selecting a focusing area in the image or video sequence reproduced by the display, depending on the obtained gazing direction;

- focusing the recorded image or video sequence of the environment surrounding the device by means of the autofocus arrangement so that the object or objects within the focusing area becomes sharp.

Further advantages of the present invention and embodiments thereof will appear from the following detailed description of the invention.

It should be emphasized that the term "comprises/comprising" when used in this specification is taken to specify the presence of stated features, integers, steps or components, but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.

It should also be emphasised that the methods defined by the appended claims may, without departing from the present invention, be performed in another order than the order in which they appear in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will now be described in more detail in relation to the enclosed drawings, in which:

Fig. 1 shows a first side of a portable communication device in the form of a cell phone,

Fig. 2 shows a second side of the portable communication device in Fig. 1 ,

Fig. 3 shows the cell phone in Fig. 1-2 connected to a cellular network,

Fig. 4 shows a schematic block diagram of the relevant parts of the cell phone in Fig. 1-3,

Fig. 5 shows a user utilizing the cell phone in Fig. 1-3,

Fig. 6a shows the head of a user 50 turned substantially straight forward,

Fig. 6b shows the head of a user 50 turned to the left with respect to the user,

Fig. 6c shows the head of a user 50 turned to the right with respect to the user, Fig. 7a shows a focus grid over the display 22 with focus in the centre of the grid,

Fig. 7b shows the focus grid in Fig. 7a with focus to the left in the grid,

Fig. 7c shows the focus grid in Fig. 7a with focus to the right in the grid,

Fig. 8a shows the display of the cell phone in Fig. 1-3 reproducing an exemplifying and schematic image, Fig. 8b shows the display of the cell phone in Fig. 1-3 reproducing an exemplifying and schematic image, Fig. 9 shows a flowchart of a method of performing the method according to a preferred embodiment of the invention. Fig. 10 shows a CD ROM on which program code for executing the method according to the invention is provided.

o

DETAILED DESCRIPTION OF EMBODIMENTS

The present invention relates to portable devices comprising an imaging system. In particular, the invention relates to portable communication devices comprising an imaging system. However, the invention is by no means limited to communication devices. Rather, it can be applied to any suitable portable device comprising a suitable imaging system.

An exemplifying portable communication device according to a preferred embodiment of the invention is shown in Fig. 1-2. Preferably, the device is a mobile cell phone 10 adapted to operate according to 3G-technology (e.g. W-CDMA or CDMA2000) or possibly according to 2,5-technology (e.g. GPRS) or similar technology. Information about 3G- technology and 2,5-technology can e.g. be found in specifications from the 3 rd Generation Partnership Project (3GPP), see e.g. the web-site at www.3qpp.org.

However, it should be emphasised that the cell phone 10 in Fig. 1 -2 is just one example of a portable device in which the invention can be implemented. In addition, the invention can for instance be used in a PDA (personal digital assistant), a palm top computer, a lap top computer or a smartphone or any other suitable portable device.

Figure 1 shows a first side of the cell phone 10 i.a. comprising a keypad 12, a loudspeaker 14 and a microphone 16. The keypad 12 is used for entering information such as selection of functions and responding to prompts. The keypad 12 may be of any suitable kind, including but not limited to keypads with suitable push-buttons or touch- buttons or similar and/or a combination of different suitable button arrangements. The loudspeaker 14 is used for presenting sounds to the user and the microphone 16 is used for sensing the voice from a user. In addition, the cell phone 10 includes an antenna, which is used for communication with other users via a network. The antenna is in-built in the cell phone 10 and hence not shown in Fig 1.

Moreover, the first side of the cell phone 10 shown in Fig. 1 comprises a display 22 for displaying functions and prompts to a user of the cell phone 10. The display 22 is also utilized for presenting images and/or video sequences. Here, it should be emphasised that the display 22 is preferably arranged to present images and/or video sequences

previously recorded as well as images currently recorded. In other words, it is preferred that the display 22 can operate both as a viewfinder and as presentation device for previously recorded images and/or video sequences.

In addition, the first side of the cell phone 10 shown in Fig. 1 comprises a first camera arrangement 24a for enabling images to be digitally recorded by the cell phone 10. It is preferred that the first camera 24a comprises a lens and/or a lens system and a image sensor such as an CCD (Charged Couple Device) image sensor built on an integrated circuit containing an array of linked, or coupled, capacitors or similar being sensitive to light. Naturally, other image sensors are conceivable, e.g. such as an APS (Active Pixel Sensor) built on an integrated circuit containing an array of pixels, each containing a photo detector as well as three or more transistors. The APS can be produced by an ordinary CMOS process and it consumes less power that the traditional CCD. The first camera 24a is typically a video-call camera for recording images and/or video sequences of the user of the cell phone 10 during a video-call as is well known to those skilled in the art. A video-call camera function or similar is e.g. available in the Sony-Ericsson mobile cellular phones P990i, W850i, K610i and Z610L

Figure 2 shows a second side of the cell phone 10 comprising a second camera arrangement 24b. Typically the second camera 24b comprises the same or similar basic structures and functions as the first camera arrangement 24a. However, the second camera 24b is preferably the main camera of the cell phone 10 and it is therefore preferred that the second camera 24b has an enhanced performance compared to the first camera 24a, e.g. a higher resolution. In particular, the second camera 24b is provided with an autofocus arrangement or similar for obtaining the correct focus of an image to be recorded. An autofocus function is e.g. available in the Sony-Ericsson mobile cellular phones P990i, W900i, K800i and W810i. The basic structure and function of various suitable autofocus arrangements are well known to those skilled in the art and they need no further description.

Fig. 3 shows the cell phone 10 connected to a cellular network 30 via a base station 32. The network 30 is preferably a 3G network such as a WCDMA network, but it may also be a GPRS network or any other 2,5G or 2,75G network. However, the network does not have to be a cellular network but can be some other type of network, such as Internet, a corporate intranet, a LAN or a wireless LAN.

Fig. 4 shows parts of the interior of the cell phone 10 being relevant for the present invention. As previously explained, it is preferred that the cell phone 10 comprises a keypad 12, a speaker 14, a microphone 16, a display 22, a first camera arrangement 24a and a second camera arrangement 24b. In addition, the cell phone 10 is preferably provided with a memory arrangement 18 for storing e.g. system files and data files, in particularly files comprising images produced by the second camera arrangement 24b. The memory 18 may be any suitable memory or combination of memories used in portable devices.

In addition, the cell phone 10 comprises an antenna 34 connected to a radio circuit 36 for enabling radio communication with the network 30 in fig. 3. The radio circuit 36 is in turn connected to an event handling unit 19 for handling such events as outgoing and incoming communication to and from external units via the network 30, e.g. calls and messages, e.g. SMS (Short Message Service) and MMS (Multimedia Messaging Service).

Furthermore, the cell phone 10 is provided with a control unit 20 for controlling and supervising the operation of the cell phone 10. The control unit 20 may be implemented by means of hardware and/or software, and it may comprise one or several hardware units and/or software modules, e.g. one or several processor units provided with or having access to the appropriate software and hardware required for the functions to be performed by the cell phone 10, as is well known by those skilled in the art. As can be seen in Fig. 4, it is preferred that the control unit 20 is connected to the keypad 12, the speaker 14, the microphone 16, the event handling unit 19, the display 22, the cameras 24a and 24b, the radio unit 36 and the memory 18. This provides the control unit 20 with the ability to control and communicate with these units to e.g. exchanging information and instructions with the units.

The autofocus-control 40 comprised by the control unit 20 is of particular interest in connection with the present invention. Being a part of the control unit 20 implies that the autofocus-control 40 can be implemented by means of hardware and/or software and it can comprise one or several hardware units and/or software modules, e.g. one or several processor units provided with or having access to the software and hardware appropriate for the functions required. The autofocus-control 40 is arranged to operatively control the

autofocus arrangement of the second camera 24b by means of recordings of the face of a user 50 made by the first camera 24a as will be described in more detail below.

Figure 5 shows the head of a user 50 utilizing the cell phone 10 according to an embodiment of the present invention. As can be seen in Fig. 5 the cell phone 10 is preferably maintained in an operational position in front of the user 50. The operational position is selected so that the first camera 24a can record images of the head of the user 50 positioned in front of the display 22, which in operation reproduces the scenery currently recorded by the second camera 24b.

The autofocus-control 40 is arranged to operatively process images of the face of the user 50 recorded by the first camera 24a so as to obtain the gazing direction of the face and/or the gazing direction of the eyes of the user 50. Here, it is assumed that the face and/or the eyes are directed toward the object to be recorded by the second camera 24b. However, it should be added that the face and/or the eyes of the user 50 may alternatively be directed towards the camera 24a and the display 22 of the cell phone 10. The obtained gazing directions of the face and the eyes may supplement each other, e.g. if the obtained direction of the face or eyes is uncertain or in case the user gazes obliquely towards the object to be recorded, i.e. the eyes are directed towards the object to be recorded whereas the face is directed otherwise, or the other way around.

The direction of the face and the direction of the eyes can e.g. be obtained by means of a suitable face recognition method or similar and by a suitable eye tracking algorithm or similar. For this purpose there is a wide range of well known face recognition techniques for detecting the direction of the user's face in a recorded image or recorded sequence of images, see e.g. the published patent application US 2001/0019620 {Nagai et al.). Similarly, there are a wide range of well known eye tracking techniques for detecting the gazing direction of the user's eyes, see e.g. the patent US 6,152,563 (Hutchinson et. al) and the published patent applications US 2006/01 10008 A1 (Vertegaal et al.) and US 2006/0007396 A1 {Clement et al.). Those skilled in the art, having the benefit of this disclosure, recognize similar or equivalent methods suitable for tracking the face direction and the gaze direction of the eyes of a user 50 by means of recordings from the first camera 24a. For example, the gaze tracking of the eyes of a user 50 may be performed by means of infrared illumination which is reflected by the exterior and/or interior of the eyes and then recorded by the first camera arrangement 24a. The infrared light is

reflected from the eye and sensed by the camera arrangement 24a. The information is then analyzed by the autofocus-control 40 to extract eye rotation from changes in reflections. Typically, the corneal reflection (the first Purkinje image) and the centre of the pupil may be used as features to track over time. A more sensitive type of eye tracker, the dual-Purkinje eye tracker, uses reflections from the front of the cornea (first Purkinje image) and the back of the lens (fourth Purkinje image) as features to track. A still more sensitive method of tracking is to image features from inside the eye, such as the retinal blood vessels, and follow these features as the eye rotates.

The autofocus-control 40 is further adapted to control the autofocus arrangement of the second camera 24b so as to change the focus of the image to be recorded by the second camera 24b depending on the direction of the face and/or the direction of the eyes obtained for the user 50 by means of images recorded by the first camera 24a.

As schematically illustrated in Fig. 6a — 6c, it is preferred that the autofocus-control 40 is arranged to operatively detect at least the direction of the user's 50 face when the user's face is turned substantially straight ahead as schematically illustrated in Fig. 6a, to the left as schematically illustrated in Fig. 6b and to the left as schematically illustrated in Fig. 6c.

As schematically illustrated in Fig. 7a — 7c, the display 22 of the phone 10 may be divided into a focus grid 700, e.g. a grid comprising nine square shaped areas. The grid may be visible or invisible to the user 50 and it may comprise more or less squares or other suitably defined focusing areas than those schematically shown in Fig. Ia-Ic. For example, the focusing areas in the grid may alternatively have the shape of a rectangle or some other polygonal shape, or a circle or an oval or a polygonal shape with rounded or slanted corners etc.

The grid 700 is correlated to the face direction of the user 50 and/or the direction of the eyes of the user 50, which e.g. can be obtained by well known face recognition methods or eye tracking algorithms or similar as mentioned above. Hence, when the face of the user 50 is turned substantially straight ahead as illustrated in Fig. 6a the autofocus-control 40 will focus the image presented on the display 22 so that it becomes sharp in the centre square of the grid 700, as schematically indicated by a circle in Fig. 7a. Similarly, when the face of the user 50 is turned to the left as illustrated in Fig. 6b the autofocus-control 40 will focus the image presented on the display 22 so that it becomes sharp in the left

square of the grid 700, as schematically indicated by a circle in Fig. 7b. When the face of the user 50 is turned to the right as illustrated in Fig. 6c the autofocus-control 40 will focus the image presented on the display 22 so that it becomes sharp in the right square of the grid 700, as schematically indicated by a circle in Fig. 7c. In addition, the auto-focus control 40 may be arranged to operatively detect whether the user 50 is looking up or down. In such a case one of the squares in the row below the middle row indicated above will be used mutatis mutandis when the user 50 is looking down, whereas the squares in the row above the middle row will be used mutatis mutandis when the user 50 is looking up. The above applies mutatis mutandis for the direction of the eyes of the user 50. A focusing frame may be selected and frozen when the user has gazed at a direction for a predetermined period of time. The predetermined period may e.g. be less than three seconds, less than two seconds, less than one second, less than 0,5 seconds, less than 0,4 seconds, 0,3 seconds, 0,2 seconds or less then 0,1 seconds.

As an alternative to the focusing areas in the focus grid 700 the cell phone 10 may operate by means of a movable focusing area in the form of a movable focusing frame 400 as indicated in Fig. 8a-8b. It is then preferred that the movable frame 400 is visible so that the user 50 can see the object on which the image will be focused. This provides a user with an improved control over the focusing process. The focusing frame 400 may have the shape of a square or a rectangle or some other polygonal shape. However, other shapes are clearly conceivable, e.g. a circle or an oval or a polygonal shape with rounded or slanted corners. It is further preferred that the focusing frame 400 covers less than half of the area of the displayed image, and more preferably less than 25% of the area of the displayed image, and even more preferably less than 10% of the area of the displayed image.

In case of a movable focusing frame 400 it is preferred that the autofocus-control 40 is arranged to operatively move the focusing frame 400 or similar to various positions in the display 22 depending on the current gazing direction of the face of the user 50 and/or depending on the gazing direction of the eyes of the user 50. As mentioned above, the direction of the face of the user and the gazing direction of the eyes of the user 50 can be obtained by the autofocus-control 40 comprising a suitable face recognition technique and eye tracking technique or similar for analysing the user's face and eyes the in images produced by the first camera 24a. Once the focusing frame 400 is positioned the image presented on the display 22 can be focused by the autofocus arrangement of the second

camera 24b controlled by the autofocus-control 40 processing the object or objects within the focusing frame 400 in a well known manner.

The movable focusing frame 400 can be more clearly described with reference to Fig. 8a and Fig. 8b illustrating the display 22 of the cell phone 10 in Fig. 1 presenting an exemplifying and schematic image. The image comprises a schematically illustrated person P in a near position in the foreground and a schematically illustrated tree T in a distant position in the background. Fig 8a shows the focusing frame 400 positioned so as to cover the face of the person P, which implies that the image according to the present invention will be focused so that the face of the person P is sharp, whereas the tree T in the background is out of focus. Fig 8b shows the focusing frame 400 being moved so as to cover the crown of the tree T, which implies that the image according to the present invention will be focused so that the crown of the tree T is sharp, whereas the person P in the foreground is out of focus. Hence, by moving the frame 400, covering a part of the image presented on the display 22, to different positions in the presented image it will be possible to focus the image substantially as desired. Naturally, the same applies mutatis mutandis if the display 22 is divided into a focus grid as described above, i.e. the image will be focused in the area of the grid being selected depending on the gaze direction of the face of the user 50 and/ the gaze direction of the eyes of the user 50.

An advantage provided by the present invention is that a user of the portable communication device receives an improved control of the focusing of the image. Hence, the user is not troubled by the aiming and maneuvering that is typically required by traditional autofocus systems and the user is not necessarily limited to manually choosing from a small number of fixed focusing frames. Rather, according to the embodiments discussed above, the user is only required to aim the main camera 24b of the cell phone 10 so as to capture the image to be recorded. The captured image is then focused in a simple, convenient and efficient manner depending on the gaze direction of the face of the user 50 and/or depending on the gaze direction of the eyes of the user.

It should be added that the shape of the focusing grid 700 can be changed by means of commands from the user 50, e.g. by means of commands from the buttons or similar on the keypad 12 of the cell phone 10. For example, the number of focusing areas may be changed; the shape of the focusing areas may be changed; the formation of the focusing areas may be changed so as to represent different patterns, e.g. so as to be arranged

adjacent to each other or spatially separated, arranged in a circular pattern, or a triangular pattern or some other polygonal pattern etc. This makes it possible to focus on a small object by using small focusing areas and to focus on a large object or several small objects by using larger focusing areas. In short, it enables an adjustment of the form and size of the focusing areas so as to fit the object or objects to be focused.

Likewise, the shape of the movable focusing frame 400 can be changed by means of commands from the User 50, e.g. by means of commands from the buttons or similar on the keypad 12 of the cell phone 10. This makes it possible to focus on a small object by using a small frame and to focus on a large object or several small objects by using a larger frame. In short, it enables an adjustment of the size of the focusing frame to fit the object or objects to be focused. In short, it enables an adjustment of the form and size of the focusing frame 400 so as to fit the object or objects to be focused.

Before we proceed it should be emphasised that in addition to the parts and units shown in Fig. 3 there may be further parts and units or similar present in the cell phone 10. The parts and units shown in Fig. 3 may also be connected to more parts and units than illustrated.

The attention is now directed towards the function of an exemplifying embodiment of the present invention, which will be described with reference to Fig. 1— 8b, and Fig. 9 showing a flow chart of a preferred embodiment of a method according to the invention.

As previously explained, a cell phone 10 according to an embodiment of the present invention comprises a first camera 24a that is primarily arranged for recording images and/or video sequences of the user 50 during a video-call. In addition, the cell phone 10 comprises a second camera arrangement 24b for recording high-quality images of the environment surrounding the cell phone 10. In particular, as will be explained in more detail below, the second camera arrangement 24b is provided with an autofocus arrangement that is arranged to be operatively controlled by the autofocus-control 40 operating on recordings of the face and/or the eyes of a user 50 made by the first camera

24a.

Advantageous embodiments of the present invention uses a communication device provided with two cameras, which e.g. is typical for cell phones enabled for video-calls.

The main advantage is that an implementation of the invention in a communication device enabled for video-calls by means of two cameras does not require any auxiliary hardware (at least not an auxiliary camera), i.e. the required hardware is already in place.

The steps in an exemplifying method of focusing an captured image by means of the autofocus arrangement of the second camera 24b utilizing recordings of the face and/or the eyes of a user 50 made by the first camera 24a for positioning a movable focusing frame, covering a part of the captured image reproduced on the display 22, will now be described with reference to the exemplifying flow chart in Fig. 9. The method is preferably implemented by means of the autofocus-control 40 as schematically illustrated in Fig. 4.

In a first step S1 of an exemplifying method according to an embodiment of the present invention the focusing function preformed by the autofocus-control 40 is initialised. The initialisation may include such actions as recording an image of the user 50 by using the first camera 24a, recording an image of the environment surrounding the cell phone 10 by using the second camera 24b and reproducing the recorded images of the surrounding environment by means of the display 22. In addition it is preferred that the initialisation comprises an allocation of a focusing grid (typically invisible to the user 50) on the display 22, or a movable focusing frame 400 on a start position in the display 22.

In a second step S2 of the exemplifying method the direction of the face and/or the eyes of the user 50 is obtained by means of the autofocus-control 40 being arranged to operatively process images of the face of the user 50 recorded by the first camera 24a. The recorded images of the face of the user 50 are preferably processed by the autofocus-control 40 utilizing a suitable face recognition technique or similar and possible a suitable eye tracking technique or similar as previously described. Here it is assumed that the user 50 has the face and eyes directed towards the object to be recorded by the second camera 24b. If we take Fig. 8a as an example the user 50 may have the face and eyes directed at the person P or at the tree T as they appear in the environment surrounding the cell phone 10. In any case, known face or eye tracking algorithms or similar can at least detect whether the face and possibly the eyes of the user 50 are directed straight ahead, or to the left or to the right, up or down. In addition, known face or eye tracking algorithms can be used to detect whether the face and/or eyes of a user 50 are directed towards the camera 24a and the display 22 of the cell phone 10 and also to detect the area in the display 22 at which the user 50 is gazing. Hence, it is possible to

detect whether a user 50 gazes towards the person P or the tree T as they appear on the display arrangement 22 of the cell phone 10.

In a third step S3 of the exemplifying method the focusing area is selected according to the gazing direction of the face and/or the eyes of the user 50 obtained in the previous step S2.For example, an area in a focusing grid can be selected accordingly as previously described with reference to the exemplifying Fig. 6a-6c and Fig. 7a-7c. Similarly, a focusing frame 400 can be moved accordingly as illustrated in Fig. 8a and 8b.

It is preferred that the focusing area is selected by the autofocus-control 40. However, the autofocus-control 40 may alternatively provide another hardware and/or software unit with the obtained direction of the face and/or eyes of the user 50, which unit in turn selects focusing area within the image reproduced by the display 22.

In a fourth step S4 of the exemplifying method the object of interest that is identified by the focusing area is selected, e.g. in that the user pushes a button or the like on the keypad 12 or similar, or in that the user simply stops moving the face and/or the eyes for a short period. The autofocus-control 40 uses the part of the image delimited by the focusing area to focus the image so that the object or objects within the focusing area becomes sharp. This is typically performed by selecting the focus setting that renders the best sharpness within the focusing area, which is routinely done in almost all digital cameras having traditional autofocus. For this purpose the image within the focusing area can be analyzed by means of e.g. an edge detection algorithm according to which the autofocus setting that shows most edges within the focusing frame is selected to focus the image since it represents the sharpest image, c.f. e.g. the published patent application US 2006/0062484 A1 (Aas et. al).

In general, as previously explained, it is preferred that the autofocus-control 40, arranged to perform the exemplifying method described above, is provided in the form of one or more processors with corresponding memory containing the appropriate software in the form of a program code. However, the program code can also be provided on a data carrier such as a CD ROM disc 46 as depicted in Fig. 8 or an insertable memory stick, which will perform the invention when loaded into a computer or into a phone having suitable processing capabilities. The program code can also be downloaded remotely

from a server either outside or inside the cellular network or be downloaded via a computer like a PC to which the phone is temporarily connected.

As a general remark it should also be added that the expression "image" used above may include video sequences if this is more appropriate in some embodiments of the invention.

The present invention has now been described with reference to exemplifying embodiments. However, the invention is not limited to the embodiments described herein. On the contrary, the full extent of the invention is only determined by the scope of the appended claims.