The invention relates to mobile telephones with high data rates able to capture and display images for videotelephone calls. Such telephones are also called videotelephone terminals. The invention relates more particularly to adjusting the image capture means.
In the field of telecommunications, the introduction of high bit rates has made videotelephone services available to the consumer. More particularly, third generation mobile telephone networks, such as UMTS (Universal Mobile Telecommunication System) networks, for example, enable mobile telephones or terminals to provide videotelephone applications.
Videotelephones enable two people to see each other while communicating at a distance. To this end, the terminal of each person has a display screen and a camera. Mobile terminals have a small screen with low definition and it is important to have good foreground framing if the other party's face is to be seen clearly.
One drawback arises from the fact that a party A communicating with a party B sees only what is sent by the camera of the party A. Since the party B has no control of framing, it is the party A who must take care of controlling what is shot by his or her own camera. This control over what is being shot by the camera can be assisted by displaying a thumbnail in a corner of the screen. The parties must then ensure that their own images remain centered in the thumbnail.
That kind of framing system is somewhat impractical, for numerous reasons. It reduces the usable area of the display screen of the terminal, which is small enough in the first place. The parties must pay careful attention to framing their own images. The framing motions do not come naturally, as the thumbnail shows an image shot with left to right inversion.
Using a remote control camera for fixed videoconference systems is known in the art. Thus a party A can adjust the camera of a party B and vice-versa. Each user has a remote control for sending zoom and tracking commands. Because mobile terminal cameras are generally not mobile and such adjustments would require using the keys of the keypad of the terminal during the call, such a system cannot be used in a mobile terminal. The keys of a mobile terminal are small and it would be somewhat impractical to use them whilst holding the terminal so that it faces in a given direction to achieve the necessary framing.
EP-A-1 304 853 describes a mobile device, such as a mobile telephone, including a still camera and motion sensors. The camera captures a plurality of images of an object and those images are then combined. Synchronized motion information supplied by the motion sensors is used to realign the images to be combined. This concept does not employ two remotely sited videotelephone terminals.