Cross References

This application claims priority to a U.S. Provisional

Application, Serial No. 62/054,710, filed on September 24, 2014, which is herein incorporated by reference in its entiret . Field of the Invention

The present invention is directed to video telephony and, in particular, to an arrangement for enhancing light conditions to which a participant in a video conference is exposed .

Background of the Invention

Videoconferencing using, for example, Skype or Facetime has become a common tool in the home environment. In a video conference, video cameras are used to allow participants at remote endpoints to view and hear each other. When a participant is exposed to insufficient light condition, the image of the participant displayed at the receiving end may be of low quality. It may be desireable to utilize the light produced in a display screen for illuminating or lightening up a head/face of a participant in the videoconference . A first participant and a remote second participant may participate in the video conference.

In an advantageous embodiment, a camera of a

videotelephony device, for example, a smart phone, a television receiver, a personal computer or a tablet, is used by first participant and, for example, a remote second participant that may participate in the video conference. The camera generates a video signal containing a camera captured image, for example, of the face of the first participant. A video processor used in the first

participant videotelephony device is responsive to the camera generated video signal for valuating illumination, for example, brightness content of the camera generated video signal. The video processor also generates a first display drive video signal that is displayed in a first region of a display panel of the first participant

videotelephony device. The first display drive video signal has brightness content that is regulated in a feedback manner in accordance with the valuated brightness content of the camera generated video signal. The first display drive video signal enhances background lighting produced in the first region of the display panel to enhance the lighting to which an object of the camera, for example, the face of the first participant, is exposed.

The video processor additionally generates a

transmitter drive video signal containing the brightness enhanced camera generated image of, for example, the face of the first participant. The image is transmitted via a communication network, and adapted to be received by a videotelephony device of the remote, second participant and to be displayed in a display panel of the second

participant videotelepony device.

A second region of the first participant display panel is used for displaying, for example, an image of the face of the remote, second participant contained in an input video signal generated in the videotelephony device of the remote second participant and received via the

communication network by the video processor of the videotelepony device of the first participant.

Summary of the Invention

A video communication apparatus for employing an advantageous method includes an interface for receiving a video signal that can be generated by a first camera and containing a first image that can be captured in the camera. A video processor configured to valuate

illumination content of the first video signal generates a first display drive video signal that is capable of being displayed in a first region of a first display panel to generate background light capable of illuminating an object of the first camera and having illumination content that is regulated, in accordance with illumination content of the first video signal. The video processor is additionally configured to apply the first video signal for transmission in a communication network capable of being displayed in a second display panel, when received from the communication network. The video processor is further configured to receive an input video signal containing a second image from the communication network for generating a second display drive video signal containing the second image that is capable of being reproduced in a second region of the first display panel that is at least partially non- overlapping with the first region. Brief Description of the Drawings

FIGURE 1A illustrates a block diagram of a phone, for example, a prior art phone, used in a video conference; FIGURE IB illustrates a block diagram of a smart phone, embodying a particularly advantageous feature, operated by a first participant that is engaged in the video-conference with a second participant of FIGURE 1A;

FIGURE 2A illustrates an image of the second

participant of Figure 1A that is captured in a camera of the participant of Figure 1A;

FIGURE 2B illustrates a display panel of the smart phone of Figure IB having a light enhancing region;

FIGURE 3 illustrates an image of the first participant of Figure IB that is captured in the camera of Figure IB;

Figures 4A, 4B and 4C illustrate three examples, respectively, of asymmetric lighting of the participant of Figure IB;

Figure 5 illustrates a so called selfie image captured in the camera and displayed in the display of Figure IB;

FIGURE 6 illustrates a display panel of Figure 1A having a light enhancing region controlled by the phone of Figure IB; and

Figure 7 illustrates asymmetric lighting of the participant of Figure 1A controlled by the phone of Figure IB. Detailed Description

FIGURE 1A illustrates a block diagram of, for example, a prior art smart phone 300 operated by a participant A that is engaged in a video-conference with a participant B of Figure IB located, for example, remotely from participant B. FIGURE IB illustrates a block diagram of a smart phone 200, providing a particularly advantageous feature, and operated by participant B. Similar symbols and numerals in FIGURES 1A and IB indicate similar items or functions.

FIGURE 2A illustrates an image 101a of participant A of

Figure 1A that is captured in a camera 307 of phone 300 for producing a video signal 307a containing captured image 101a of Figure 2A. Image 101a includes an image portion 101b depicting a head/face of participant A, an image portion 101c depicting a body of participant A and a background portion lOld that excludes the other two image portions. Similar symbols and numerals in FIGURES 1A, IB and 2A indicate similar items or functions.

Video signal 307a of Figure 1A is coupled

substantially without video content or picture image

modification via a conventional video processor 302, implemented in, for example, a microprocessor, not shown, to a conventional receiver-transmitter stage 303 of phone 300. Receiver-transmitter stage 303 of video processor 302 transmits the content of video signal 307a in a conventional manner via a phone or data/internet communication network 400. A conventional receiver-transmitter stage 205 of Figure IB receives via network 400 the signal transmitted by receiver-transmitter stage 303 of Figure 1A that contains image 101a of Figure 2A forming an input video signal 205a of Figure IB. Input video signal 205a contains the same video or picture content as image 101a of Figure 2A.

Advantageously, a video processor 206 of Figure IB, implemented in, for example, a microprocessor, not shown, detects or recognizes in input video signal 205a a portion signal, not shown, forming an image portion 101b of Figure 2A depicting the head/face image of participant A of Figure 1A using well known pattern recognition technique.

Alternatively, the detected or recognized portion may also include a band lOle of what would be otherwise background portion lOld, in addition to the signal portion associated with head/face image portion 101b. Detecting or recognizing the head/face contained in image portion 101b is performed using a method similar to recognition methods explained, for example, in US 6,661,907, in US 6,343,141 and in an article, entitled, "Detecting Faces in Images: A Survey" by IEEE TRANSACTIONS ON PATTERN ANALYSIS AND MACHINE INTELLIGENCE, VOL . 24, NO . 1 , JANUARY 2002.

The aforementioned portion, not shown, of video signal 205a that contains head/face image portion 101b of Figure 2A of participant A is extracted and applied in a video

processor 203 to generate a display drive video signal 203b. In addition, video processor 203 of Figure IB synthesizes a display drive video signal 203c that is combined with display drive video signal 203b to form a combined display drive video signal 203a. Thus, signal 203a contains both display drive video signals 203c and 203b. Display drive video signals 203c and 203b are applied to a conventional display device 204c having a display panel 204. In display panel 204, display drive video signal 203b produces in a region 204b of display panel 204 of Figure 2B an image portion having, for example, the same picture image content as head/face image portion 101b of Figure 2A and is referred to in Figure 2B using the same symbol 101b. Similar symbols and numerals in FIGURES 1A, IB, 2A and 2B indicate similar items or functions .

In a particularly advantageous arrangement, synthesized display drive video signal 203c of Figure IB produces light in a region 204a of display panel 204 of Figure 2B that excludes head/face image portion 101b and is non-overlapping with region 204b of display panel 204. Light producing region 204a is used for generating and regulating

illumination in region 204a to lighten up, for example, the head/face of participant B forming the object of a camera 207.

FIGURE 3 illustrates an image 201a captured in camera 207 of Figure IB of participant B forming the object of camera 207. Similar symbols and numerals in FIGURES 1A, IB, 2A, 2B and 3 indicate similar items or functions.

Image 201a of Figure 3 depicts a head/face image portion 201b of participant B, a body image portion 201c of participant B and a background image portion 201d that excludes at least head/face image portion 201b of

participant B. A video signal 207a of Figure IB contains image 201a of Figure 3. Video signal 207a of Figure IB is processed in a video processor 202 implemented in, for example, the same microprocessor, not shown, which also implements processors 203 and 206 that were mentioned before. Thus, video processor 202, video processor 203 and video processor 206 may be combined to form a single video processor 250. In a particularly advantageous arrangement, video processor 202, using a pattern recognition technique referred to before, detects or recognizes and extracts a signal portion, not shown, of video signal 207a that contains the image pattern of head/face image portion 201b of Figure 3 of participant B of Figure IB to the exclusion of the rest of image 201a. Optionally, the video content of a band portion 201e may also be included in the detected and extracted portion.

In a particularly advantageous arrangement, video processor 202 of Figure IB valuates illumination exposure parameter, for example, brightness, signal-to-noise ratio content of captured image 201a or other optical

characteristics of captured image 201a of Figure 3 such as color, or a combination thereof, by analyzing the detected and extracted portion, not shown, of video signal 207a of Figure IB that contains head/face image portion 201b of Figure 3. Alternatively, the combination of head/face image portion 201b and, for example, band lOle can be used for such valuation. Illumination or brightness valuation applies well known pixel signal integration processes . In one alternative, the integration process is applied to captured image 201a of participant B of Figure 3 in its entirety. In other alternatives, the integration process is applied solely to head/ face image portion 201b or to a combination of head/face image portion 201b and portion 201e of captured image 201a of participant B of Figure IB . An output signal 202a of processor 202 contains a value indicative of the illumination such as the aforementioned brightness content exposure of the image of participant B.

The valuation may indicates that the illumination of head/face image portion 201b of Figure 3 is insufficiently low to be below a threshold level. In a particularly advantageous arrangement, a combination of the brightness content, color content and gamma correction values contained in display drive video signal 203c, that excludes the content of image of head/face image portion 101b of Figure 2A, is regulated in, for example, a closed loop negative feedback manner. The regulation is performed in accordance with the valuated illumination/brightness content in signal 202a of Figure IB. As a result, illumination of light producing region 204a of Figure 2B that excludes region 204b is controlled in a manner to vary the light exposure to which the object of camera 207 of Figure IB such as the head/face of participant B. The illumination of light producing region 204a of Figure 2B is obtained for enhancing the overall illumination or brightness content, contrast and/or color temperature in a closed loop negative feedback manner. Whenever the lighting circumstances change, adaptive sense signal 202a also changes. The brightness and/or color content of light producing region 204a of Figure 2B might be increased up to attain white color with maximum light output .

The regulated light output can be controlled by, for example, controlling light valves or cells, not shown, forming pixels of display panel 204 that may be formed using, for example, liquid crystal display (LCD) or organic light-emitting diode (OLED) technology. When, for example, the LCD technology is used, the regulated light output may be additionally or alternatively controlled by selectively controlling back lighting, not shown, of display panel 204. Advantageously, an improved or better lighted head/face image portion 201b of participant B of Figure IB is thereby obtained. For example, if participant B is located in a dark room and an exterior lighting, not shown, directed towards the head/face of participant B is poor, the brightness content of light producing region 204a of Figure 2B is increased in a negative feedback manner to an optimal value for obtaining enhanced illumination of the head/face of participant B of Figure 3. The result is that signal 207a of camera 207 of Figure IB will contain image 201a of

participant B of Figure 3 that is , advantageously,

optimally brighter.

In one example, Signal 207a of camera 207 of Figure IB is applied in video processor 203 to transmitter- receiver stage 205 that transmits via communication network 400 a transmitter drive video signal 203d of processor 203 containing image 201a of Figure 3. At a remote end,

receiver-transmitter stage 303 of Figure 1A receives transmitted drive video signal 203d and displays it, for example, unmodified, in a display panel 304 of a display device 304c of phone 300.

The enhanced lighting conditions produced in light producing region 204a of Figure 2B, controlled by the negative feedback control loop, cause image 201a of Figure 3 to be, advantageously, optimally bright when displayed in display panel 304 of Figure 1A of participant A. Thus, advantageously, even prior art phone 300 benefits from the advantageous features of advantageous phone 200 of Figure IB. Advantageous ly, the color temperature of, in

particular, the skin of the image of participant B of Figure IB may be analyzed by processor 202. As explained before, processor 203 can vary the color of light producing region 204a of Figure 2B in accordance with the analysis results of processor 202 of Figure IB. The result is that image 201a of participant B of Figure 3 that is transmitted to

participant A of Figure 1A can become, advantageously, more presentable or so-called healthier looking. If the object of camera 207 of Figure IB includes more than one person , for example, a family, resulting in more than a single head/face in the picture, each head/face can be detected or recognized and taken into account to be displayed in a similar manner described before with respect to single participant B.

Advantageously, to alleviate partial exposure to light, an under-exposed head/face portion may be selectively lightened up by light producing region 204a of display 204 to illuminate mainly the darker side in an asymmetric manner. Partial exposure occurs when only one portion of the image is poorly lighted as a result of, for example, an external light source, not shown, such as a lamp that illuminates mainly one side of the face of participant B. Figures 4A, 4B and 4C illustrate three examples of such so- called asymmetric lighting. Similar symbols and numerals in FIGURES 1A, IB , 2A, 2B, 3, 4A, 4B and 4C indicate similar items or functions.

In Figures 4A and 4B, light producing region 204a occupies only a right portion of display panel 204 for producing light output at the right side of the image of participant A that is directed to the head/face of

participant B of Figure IB . In the example of Figure 4B, the proportional size of head/ face portion 101b is scaled down and relocated to the left and down. Whereas, the area of light producing region 204a becomes proportionally larger than in Figure 4A to allow for better asymmetrical lighting .

In Figure 4C, head/ face image portion 101b is relocated to one corner or side allowing the rest of the area for producing more light output at the lower and right sides of head/ face portion 101b that is directed to the head/face of participant B of Figure IB . The size of the area occupied by light producing region 204a of Figures 4A, 4B and 4C is regulated by processor 203 of Figure IB in accordance with valuated illumination distribution content in head/face image portion 201b of Figure 3. In a particularly advantageous arrangement, phone 200 of Figure IB is also capable of providing enhanced lighting content of head/face image portion 201b of Figure 3 of participant B of Figure IB also when camera 207 is used, in a manner unrelated to video telephony, to capture and store, for example, a self-portrait photograph referred to as selfie. For this purpose, the portion, not shown, of video signal 207a that contains mainly head/face image portion 201b of Figure 3 of participant B is extracted and applied in video processor 203 to generate display drive video signal 203b of display drive output video signal 203a of video processor 203. This is done in an analogous manner described before with respect to Figure 2B. A main

difference is that, instead of displaying head/face image portion 101b of participant A in display panel 204 of

Figure 2B, display drive video signal 203b contains mainly the extracted head/face image portion 201b of participant B of Figure 3 for display in display panel 204 of Figure 5. Similar symbols and numerals in FIGURES 1A, IB, 2A, 2B, 3, 4A, 4B, 4C and 5 indicate similar items or functions. In this way, participant B can view his head/face image portion 201b captured by camera 207 of Figure IB. If the aforementioned content illumination valuation performed in processor 202 indicates that the brightness values of head/face image portion 201b of Figure 3 is insufficiently low, a combination of the brightness content, color content and gamma correction values associated with display drive video signal 203c is regulated in, for

example, a closed loop negative feedback manner. The

regulation is performed in accordance with the

illumination/brightness content in signal 202a of Figure IB. The illumination of light producing region 204a of Figure 5 is controlled in a manner to vary the light exposure to which the selfie picture taker B is subjected in a manner to enhance the overall brightness content, contrast and color temperature in a closed loop feedback manner. It should be understood that the advantageous features described before in connection with Figures 2B and Figures 4A-4C are also applicable in an analogous manner with respect to capturing and storing a selfie.

As explained before, when participants A and B of

Figures 1A and IB, respectively, participate in a

videotelephony conference, a portion, not shown, of video signal 207a that contains head/face image portion 201b of Figure 3 of participant B is extracted and applied in video processor 203 of Figure IB to generate a transmitter drive output video signal 203e. Transmitter drive output video signal 203e is contained in the aforementioned transmitter drive output video signal 203d. Transmitter drive video signal 203e has, for example, substantially the same visual content as the aforementioned extracted portion signal containing just head/face image portion 201b of Figure 3 of participant B of Figure IB. In addition, video processor 203 of Figure IB synthesizes a transmitter drive video signal 203f that is also contained in signal 203d. Thus, signal

203d that contains both signals 203e and 203f is applied to receiver-transmitter stage 205 that transmits signal 203d via network 400. Receiver-transmitter stage 303 of Figure 1A that receives signal 203d via network 400 displays it, for example, without modifying its visual contents, in display panel 304 of Figure 6 of phone 300 of Figure 1A. Similar symbols and numerals in FIGURES 1A, IB, 2A, 2B, 3, 4A, 4B, 4C, 5 and 6 indicate similar items or functions. In display panel 304 of Figure 6, display drive video signal 203e produces an image portion having, for example, the same visual content as the head/face image portion 201b of Figure 3 for display in a display region 304b of display panel 304 of Figure 6. Video processor 206 of Figure IB, for example, in addition to extracting head/face image portion 101b of Figure 2A for display in display panel 204 of Figure IB, in the manner described before , also valuates the illumination exposure of image 101a of Figure 2A received from

participant A of Figure 1A. Optionally, video processor 206 of Figure IB also valuates other optical characteristics such as color of image 101a of Figure 2A contained in video signal 205a of Figure IB. Such valuation applies well known pixel signal integration processes in the manner described before with respect to head/face image portion 201b of Figure 3.

In one alternative, an integration process is applied to the content of captured image 101a of participant A of Figure 2A in its entirety. In other alternatives, video processor 206 of Figure B detects or recognizes the pattern of head/face image portion 101b of Figure 2A. Then, the integration process is applied solely to the portion of signal 205a of Figure IB that corresponds to head/ face image portion 101b of Figure 2A or to a combination of image portion 101b and portion lOle of captured image 101a of participant A. The result of such valuation is contained in an output signal 206a of processor 206 containing brightness values indicative of the extent of illumination exposure on head/face image portion 101b of Figure 2A of participant A.

Advantageously, if the analysis of the content of signal 206a of Figure IB indicates that the

illumination/brightness content valuation associated with the image of participant A of Figure 2A is insufficiently low, for example, below a threshold level, video processor 203 of Figure IB synthesizes transmitter drive video signal 203f in a manner to produce light in a region 304a of

Figure 6 of display panel 304 of Figure IB. Region 304a of Figure 6 excludes head/face image portion 201b of region 304b and is non-overlapping with region 304b of display panel 304. Light producing region 304a is used for

generating and regulating in a negative feedback manner illumination in region 304a to lighten up, for example, the head/face of participant A of Figure 1A forming the object of camera 307. This is done, advantageously, for controlling illumination such as brightness content directed to the head/face of participant A of Figure 1A in an analogous manner by which illumination producing region 204a of Figure 2B is lightened up. Thus, the illumination of light

producing region 304a of Figure 6 may be controlled to vary the light exposure on participant A of Figure 1A in a manner to enhance the overall brightness content, contrast content and/or color temperature in a closed loop negative feedback manner. Whenever the lighting circumstances change,

correction signal 206a of Figure IB is adaptive to that change. The brightness content of light producing region 304a of Figure 6 might be increased up to optimal light output. In an analogous way to the way described before with respect to Figures 4A, 4B and 4C, the head/face of

participant A may be lightened up by light producing region 304a of display panel 304 that illuminates a darker side of head/face image portion 201b of Figure 7 in an asymmetric manner. Similar symbols and numerals in FIGURES 1A, IB, 2A, 2B, 3, 4A, 4B, 4C, 5, 6 and 7 indicate similar items or functions .