CN102783156A - Ambience lighting system using global content characteristics - Google Patents

Abstract

The invention relates to an ambience lighting system, typically for use in conjunction with a display device. The ambience lighting system may be of the type AmbiLight. The ambience lighting system comprises one or more light sources associated to subregions of the display screen; a content characterizer for determining content characteristics of image data of the subregions; and a controller to control the color of the emitted ambience light in accordance with determined content characteristics. The content characterizer is further adapted to determine content characteristics of a global region of the display screen, and the controller is adapted to control the color of the emitted ambience light in accordance with the determined content characteristics of the subregions and of the global region.

Description

Mood lighting system using global content properties

technical field

The present invention relates to an ambient lighting system and in particular to an ambient lighting system visually suitable for use in conjunction with a display device.

Background technique

Many different types of display devices, such as televisions based on various technologies, are known and available to users. Display devices are generally employed to present an image or sequence of images to a viewer. In the 1960s, backlighting was introduced due to the fact that televisions required a "darker" space for optimal viewing. Backlighting in its simplest form is white light emitted from, for example, a light bulb, onto the surface behind the visual display device. Backlighting has been suggested to relax the iris and reduce eye strain. Backlighting technology has become more complex in the last few years and there are several display devices on the market with integrated backlighting features that enable the emission of colors with different brightnesses depending on the visual information presented on the display device. The benefits of backlighting generally include: a deeper and more immersive viewing experience; improved color, contrast, and detail for optimal image quality; and reduced eye strain for more relaxed viewing. One example of a commercially available display device with backlighting is the Ambilight( ^TM) ambient lighting system sold by Philips.

A typical Ambilight ^™ system includes light sources arranged along the periphery for emitting light that is visible to the user to illuminate the area around the TV (television) screen. The Ambilight ^™ system is known to extrapolate the edges of screen content by manipulating the color of the light sources to mimic the color of the edge regions adjacent to individual light sources. The light source is controlled to mimic content characteristics such as the brightness and saturation of the upper edge regions of the screen.

Contents of the invention

The inventors of the present invention have realized that ambient lighting systems can in some situations be perceived as distracting the viewer from the content presented on the display screen. The inventors have also realized that this situation arises when there is a discrepancy between the content property of content placed near the edge and the overall impression of this content property. To this end, it would be advantageous to implement an ambient lighting system that provides an even deeper and more immersive viewing experience than achievable in current systems. Furthermore, it would also be desirable to provide an ambience system that enables a user to apply individual settings on the ambience lighting system. In general, the invention preferably aims to mitigate, alleviate or eliminate one or more of the above mentioned or other disadvantages of the prior art singly or in any combination.

To better address one or more of these concerns, in a first aspect of the invention there is proposed an ambient lighting system for use in conjunction with a display device comprising a display screen and

one or more light sources adapted to emit ambient light, the one or more light sources arranged in a configuration such that light emitted therefrom illuminates an illuminated area visually seen by a viewer, the one or more The light sources are respectively associated to the sub-areas of the display screen;

a content characterizer adapted to determine content characteristics of the image data for the sub-region of the display screen;

a controller adapted to control a color of the emitted ambient light of the one or more light sources in dependence on the determined content characteristic;

wherein the content characterizer is further adapted to determine content characteristics of a global area of the display screen, and wherein the controller is adapted to control emission of the one or more light sources as a function of the determined content characteristics of the image data of the sub-regions as well as the global area The color of the ambient light.

By determining the content properties of the image data of the sub-regions as well as the global area, it is possible to modulate the local color settings by the global content properties to obtain a system in which localized lighting is integrated in the total lighting of the whole device. For example, if very bright content displayed near the edge of the display screen in an overall dark scene results in bright coloring of ambient lighting in the same area, this may be perceived as distracting by many users. By instead dimming the ambient lighting in this area without emphasizing too much the bright parts of the scene, the viewing experience can be perceived as more relaxing.

In advantageous embodiments, the mood lighting system is of the type in which the light sources are placed on the periphery of the display device or on the rear side of the display device, where the illuminated area visually seen by the viewer at least partially surrounds the display screen. In various embodiments, the light source may emit light on a wall or screen behind the display device to provide a backlight lighting system or emit light outwardly towards the viewer to provide an ergo lighting system. In other embodiments, however, the ambient lighting system may be located separately from the display device. The term mood lighting should be read broadly in the context of the present invention and generally encompasses any system capable of emitting dynamic light based on an input signal to affect the general lighting of a room or other environment. Control of the light source can be done in many ways and is generally known to the skilled person. In an example, the controller receives input related to characteristics such as intensity and color, which is translated into operational settings such as power settings on the individual sources.

In general, a display screen can be partitioned into sub-regions, sections or blocks from which local content characteristics are extracted. In advantageous embodiments, a sub-area is an area in an edge area of the display screen in which a light source is associated to its adjoining sub-area. In such an embodiment, the ambience system may thus extrapolate properties of content displayed in the edge region of the display device beyond the edge itself. However, subregions in general can be associated to other regions of the display screen, and in principle to any subregion of the display screen. In addition to sub-areas, global areas can also be defined from which global content properties can be extracted. In various embodiments, the global area may be the entire display screen or a significant portion of the display screen. The shape or form of a sub-region or global region is not limited to any particular shape or form, in particular a region need not be limited to a single coherent region but may be formed of separate or contiguous blocks.

In advantageous embodiments, the content characteristic is selected from the group consisting of: a measure of brightness, a measure of contrast, a measure of saturation, a measure related to the dynamics of the content displayed on the display screen, or a measure of the content displayed on the display screen , measurement of 3D depth of audio content or a combination of one or more thereof accompanying the content displayed on the display screen. The graphics processors of modern televisions can generate many content characteristic measurements for many reasons. In various embodiments, such content characteristic measurements generated for other purposes may be used in conjunction with controlling emitted ambient light. In general, however, any suitable content characteristic may be used.

In an advantageous embodiment, the system further comprises an input unit adapted to receive an input command from a user; and wherein the controller is further adapted to control the color of the emitted ambient light of the one or more light sources in dependence on the received input command. An advantage of embodiments of the present invention is that the present invention enables device control of emitted ambient light on the one hand, but nonetheless supports user preferences on the other hand. Embodiments supporting specific user preferences may thus be provided.

In a second aspect of the invention there is provided a controller for controlling the color of emitted ambient light of an ambient lighting system, the controller being operatively connected to the ambient lighting system. The controller comprises or is communicatively connected to a content characterizer adapted to determine content characteristics of subregions and a global region of a display screen associated to the ambient lighting system; wherein the controller is adapted to The determined content characteristics of the area control the color of the emitted ambient light of the one or more light sources. The controller is thus provided with functionality suitable for operating the light sources of the mood lighting system of the first aspect.

In a third aspect of the present invention, a display device comprising the ambient light system according to the first aspect is provided. Such a display device may be in the form of an LCD device, a plasma device, an organic light emitting diode (OLED) device or a projection screen.

In a fourth aspect of the invention there is provided a method of operating an ambient lighting system for use with a display device. The device includes a display screen. The ambient lighting system may be a system according to the first aspect of the invention,

This method contains:

associating each of said one or more light sources to a sub-region of the display screen;

determining content characteristics of a sub-region of the display screen;

determining the content characteristics of the global area of the display screen;

The color of the ambient light emitted by the one or more light sources is controlled depending on the determined content characteristics of the sub-regions and the global region.

In a fourth aspect of the invention there is provided a computer program product which, when run on a computing device, can be implemented to perform the method steps of the third aspect of the invention.

In general the various aspects of the invention may be combined and coupled in any way possible within the scope of the invention. These and other aspects, features and/or advantages of the invention will be apparent from and elucidated by the embodiments described hereinafter.

Description of drawings

Embodiments of the invention will be described, by way of example only, with reference to the drawings, in which

Figure 1 illustrates an embodiment of a display device 1 in the form of a TV equipped with an ambient lighting system;

Figures 2A and 2B show schematic and simplified illustrations of various embodiments of the invention;

Figure 3 schematically shows an example of a transfer function that maps global saturation;

4 is a schematic illustration of the operation of an ambient lighting system in accordance with an embodiment of the present invention; and

Fig. 5 schematically illustrates an embodiment of the usual steps in the operation of an ambient lighting system according to the invention.

Detailed ways

Figure 1 illustrates an embodiment of a display device 1 in the form of a TV equipped with an ambient lighting system according to embodiments of the invention. As an example, the display device may be a flat screen TV with an Ambilight ^™ backlight sold by Philips. In the following, the focus is on embodiments of a display device in the form of a television set with an at least partly peripheral backlighting system, however the invention is not limited to such a system, but rather embodiments of the invention can be used in any type of use environment Illuminated visual display systems. An example of an alternative or additional ambient lighting system is a separate lighting source, such as a lamp with a lamp driver communicatively connected to a TV screen, such that the illumination or light emitted by this separate source varies depending on the content characteristics of a sub-area of the display screen . In this case, the average content characteristics of the sub-area can be used to drive an individual illumination source, or a dedicated sub-area or group of sub-areas can be associated to the individual illumination source.

Figure 1 illustrates an ambient lighting system for use with a display device having a display screen 3, ie a TV screen. The system comprises one or more light sources 4-7 adapted to emit ambient light. The light sources are arranged in a configuration such that light emitted therefrom illuminates the illuminated area 8 which is visually seen by a viewer. In the illustrated embodiment, there are four light sources, a top light source 5 , a bottom light source 7 and two side light sources, namely a right light source 4 and a left light source 6 . Other configurations of light sources include, but are not limited to, three light sources with top and side light sources 4-6, and two light sources that are side light sources 4,6. The illuminated area 8 can be a wall or a screen behind the TV set. In various embodiments, the light source may also be included or connected to the frame of the TV such that the frame forms part of or is the illuminated area. In the illustrated embodiment, the light sources are illustrated as four individual light sources. Each light source may however be based on a number of individually controlled units, or each illustrated light source may be understood as a simplified representation of a collection of individually controlled units.

The ambient lighting system comprises a controller 9 for controlling the light sources. Again, there may be a data processor 10 for general data processing of the system. The controller and data processor unit and possibly other units may be part of the electronics 11 of the television. Such components are typically placed in the housing of the television set behind the TV screen or image display area 3 . For illustration reasons, the elements are shown here separated from the TV. The ambient lighting system may further comprise an input unit 18 adapted to receive input commands 2 from a user. Such input commands may be associated with user preferences. Furthermore, the ambient lighting system may comprise a content characterizer 12 adapted for determining content characteristics of sub-regions 13, 14 of the display screen. These sub-regions may be associated to a light source or part of a light source 15-17, respectively, in the sense that the light emitted from the light source is based on content characteristics from the sub-region to which it is associated.

The electronic component 11 is explained in terms of functional units. In general the electronic components may be implemented as integrated circuits containing programmable components as well as certain non-programmable electronic components, wherein programmable components such as the data processor 10 may be shared between different functional units. Parts such as data processors may be implemented as content characterizers, which may likewise be included in or communicatively connected to the controller 9 . In general, the functionality of the controller and content characterizer, among other components, can be implemented by a computer program product run by the data processor 10 . The data processor 10 may, for example, be provided with the functionality to receive a computer program product 19, such as computer code, in any suitable form.

The light sources 4-7 may be different types of sources in different embodiments. The light source may be, for example, a cold cathode fluorescent lamp (CCFL) or a light emitting diode (LED), but is not limited to such a light source. For CCFL type light sources the control unit will comprise a lamp driver comprising a lamp inverter for operating the CCFL source and for light sources comprising LEDs the control unit will comprise a lamp driver for operating the LED source.

In the example shown, the color of light source element 15 may be based on the content characteristics of the subsection 14 to which it is associated, and the colors of light source elements 16 and 17 may be based on content characteristics from the subsection 13 to which they are associated. Substantially the entire edge of the display screen can be divided into a number of sub-regions distributed along the four edges.

In various embodiments, content characterizer 12 is generally implemented to determine content characteristics for all subregions of the display screen as well as for the global region of the display screen. Based on the determined content characteristic, the controller controls the color of the emitted ambient light of the source according to the determined content characteristic of the image data of the sub-region as well as the global region.

2A and 2B show schematic and simplified illustrations of various embodiments of the invention. The left side of Fig. 2A shows a situation where very bright areas near the edges in an otherwise dark screen are extrapolated by the ambient lighting system by extrapolating the full brightness. And the left side of FIG. 2B illustrates the inverse case of a dark block in an oppositely bright screen. This corresponds to the situation found in known ambience systems. Embodiments of the invention take into account the global brightness of the screen, thereby modulating the color setting of the light source with the overall brightness. This is illustrated on the right side in Figures 2A and 2B, so that full brightness is not extrapolated by the ambient lighting system, but rather the lighting is dimmed in the case of Figure 2A and increased in the case of Figure 2B.

In Figure 2, the content characteristic is in the form of brightness, however other content characteristics may be used. In a typical embodiment, the controller controls the color of the emitted ambient light of the one or more light sources based on a mathematical function that maps the determined content characteristics of the sub-regions and the global region to the color for each of said one or Output content properties for multiple lights. The output content properties are translated into relevant control settings for the light source. Besides brightness, important examples of content characteristics include saturation and dynamics. Specific examples of mathematical functions related to these three types of content characteristics are given below.

The brightness of an area (local or global) can be measured using the frame's average brightness or luma. This parameter is measured in many picture quality processing chains employed by modern TV sets. In an embodiment, the brightness of a specific light source related to a sub-region can be set according to the following general formula:

Brightness = k × sub-region brightness + (1- k ) × global brightness,

k is a constant ranging from 0 to 1. For a given sub-region, the brightness of the light source may thus be implemented as a 'fader' between the brightness of the sub-region and the global brightness.

In an embodiment, the color of the light source may be modulated by global content based on conditional criteria. For example, the device's data processor may implement a conditional state specification such that the brightness (or other content characteristic) is only modulated by the global brightness when the brightness of the sub-region is greater than the global brightness. Other conditions or predefined criteria may be used.

Saturation can be measured in several ways. For example as a measure in the form ( Max(R,G,B)-Min(R,G,B))/Max(R,G,B) or as the length of the UV vector in YUV color space. In an embodiment, the saturation is based on a transfer function of an adjustment factor from a saturation measurement of a global content attribute to a predefined saturation control of one or more light sources.

Figure 3 schematically shows an example of a transfer function that maps a global saturation 30 along the x- axis to a desaturation factor 31 expressed along the y -axis. Tests have shown that desaturated ambient lighting in a saturated scene is considered less intrusive than the opposite. This insight is reflected in the illustrated transfer function. If the global saturation is above a certain threshold, the local saturation is not adjusted (a gain of 100%, indicating that the local measured color is maintained), and when the global saturation drops below this threshold, the local measured color is Desaturation (with a gain of <100%, meaning the saturation algorithm will desaturate the input). In various embodiments, the transfer function may typically act on top of a setting defined in a generic saturation control or in a user-specified control. Furthermore, the transfer function can also be user mode dependent, e.g. above a certain user defined level, the graphics gain is set to 100%, and if e.g. the predefined saturation control for a certain user mode is already at 150% (i.e. always saturates the color to 150%), the function defined above will fade between 50% x 150% = 75% saturation and 100% x 150% = 150%. As described in connection with brightness, conditional state statements can be used to further control light sources.

This dynamic can also be characterized in several ways. A simple metric could be the sum of the lengths of the motion vectors computed for each pixel block. Motion vector calculations can also be used for motion-adaptive image quality improvement. In other embodiments, audio information may also or alternatively be used as the metric. High levels of audio loudness are often associated with exciting moments in content. In an embodiment, the dynamics of individual light sources can be adjusted by adjusting the temporal filtering settings of the ambient lighting system. In an embodiment, the general formula of the time filter is:

Output = k × current input + (1–k) × previous output.

The k-factor is usually defined by user mode. By adjusting the k-factor, the temporal behavior of individual light sources can be controlled. In an embodiment, the global dynamic settings may even be used to adjust the entire operation settings for each local color. For example, when a global dynamics metric indicates that the current scene is extremely dynamic (and thus most likely very immersive), the user mode can be automatically adjusted towards a high immersion setting. When the current scene is not dynamic at all, the user mode can be automatically adjusted towards a "relaxed" setting. In fact, more advanced systems can be defined where more global content metrics are even combined with content metadata, defining impressions of the current scene. This impression can then be used to adjust the algorithm for each color.

Figure 4 schematically illustrates an embodiment of the usual steps in the operation of an ambient lighting system according to the invention.

The content is displayed on the display screen 3 . In the illustrated embodiment, the color of the background as well as the illustrated object (fish) is desaturated. In the lower right corner there is a saturated object. The color setting for the light in the lower right corner is affected by the global color of the displayed content, for example causing a desaturation of the color of an emissive light associated to a red object.

Based on the display content, the content characterizer accesses or determines global properties 40, such as global brightness, global saturation, and global dynamics. Furthermore, the content characterizer accesses or determines local content characteristics 41, such as local brightness, local saturation and local dynamics. Both local and global characteristics are input to the functional units of the controllers 42 , 43 . In the illustrated embodiment, the controller implements two functional units, a first controller unit 42 and a second controller unit 43 . Based on the predefined 44 and adaptive 45 settings and the local content characteristics 41 of the sub-area 13, the first controller may generate an output signal 49 to control the relevant light source. In known systems, the adaptive settings may be user settings allowing the user to select a user mode or style of operation. In the present embodiment, the predefined settings and the adaptive settings are fed by the second controller unit 43 . In the illustrated embodiment the predefined settings may be stored or accessed by the second controller. Additionally, the second controller may receive user settings 47, which define a user mode or style. The settings governing the use of global properties can be split into eg predefined settings 46 implementing the used algorithm and user global settings 48 eg storing the k value for the algorithm. User settings 47, 48 and predefined settings 46 are input to the first controller module to determine output settings for controlling the light sources of the ambience system.

An advantage of the implementation described in this example is that the functionality related to global content properties can be implemented as an additional layer on top of the underlying layers dealing with local content properties, as this enables simple retrofitting of the present invention for existing systems Functionality of the various embodiments.

Fig. 5 schematically illustrates an embodiment of the usual steps in the operation of an ambient lighting system according to the invention. The ambient lighting system may eg be the system disclosed in connection with FIG. 1 . This method contains:

50: Associating each of said one or more light sources to a sub-region of a display screen;

51: Determine the content characteristics of the sub-area of the display screen;

52: Determining content characteristics of the global area of the display screen; and

53: Controlling the color of the ambient light emitted by one or more light sources according to the determined content characteristics of the sub-region and the global region.

While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive; the invention is not limited to the disclosed embodiments. Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps and the indefinite article "a" or "an" does not exclude a plurality. A single processor or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. The computer program may be stored/distributed on suitable media supplied with or as part of other hardware, such as optical storage media or solid-state media, but may also be distributed in other forms, such as via the Internet or other wired or wireless remote communication system. Any reference signs in the claims should not be construed as limiting the scope.

Claims (15)

1. atmosphere illuminator that is used to combine display unit (1) to use, this display unit (1) comprises display screen (3), and this system comprises:

One or more light source (4-7; 15-17); It is adjusted and is used to launch mood light; Said one or more light source is by the feasible field of illumination of visually seeing from the rayed beholder of its emission (8) of a kind of deployment arrangements, and said one or more light sources are associated with the subregion (13,14) of display screen respectively;

Content tokenizer (12), it adjusts the content character of the view data of the subregion that is used for definite display screen;

Controller (9), it is adapted to the color of mood light of controlling the emission of said one or more light sources according to determined content character;

Wherein the content tokenizer further is adapted to the content character of the global area of confirming display screen, and its middle controller is adapted to the color of mood light of controlling the emission of said one or more light sources according to the determined content character of subregion and global area.

2. atmosphere illuminator according to claim 1; Wherein content character is selected from the group that is made up of following: brightness measurement; Contrast is measured; Saturation is measured, with the dynamic relevant measurement of content displayed on display screen, perhaps in content displayed on the display screen, follow perhaps one or more its measurements of the 3D degree of depth of combination of the audio content of content displayed on display screen.

3. atmosphere illuminator according to claim 1; Wherein be mapped to the mathematical function of the output content characteristic that is used for each said one or more light source, the color of the mood light of the emission of the said one or more light sources of controller (9) control based on determined content character with subregion and global area.

4. atmosphere illuminator according to claim 1 further comprises input unit (18), and it is adjusted and is used for receiving input command (2) from the user; And its middle controller further is adapted to the color of mood light of controlling the emission of said one or more light sources according to the input command that received.

5. atmosphere illuminator according to claim 1, wherein subregion (13) is the zone in the fringe region of display screen, and wherein light source (16,17) is associated with the subregion that it adjoins.

6. atmosphere illuminator according to claim 2, wherein brightness measurement is based on general formula: the brightness measurement of the brightness measurement of k * subregion+(1-k) * global area, k is that scope is from 0 to 1 constant.

7. atmosphere illuminator according to claim 2, wherein the saturation measurement is based on the transfer function of the adjustment factor that measures the predefine saturation control of said one or more light sources from the saturation of overall contents attribute.

8. atmosphere illuminator according to claim 2; Wherein be based on general formula with the dynamic relevant measurement of content displayed on display screen: the previous control setting of the current control setting of k * controller+(1-k) * controller, k is that scope is from 0 to 1 constant.

9. atmosphere illuminator according to claim 1 wherein is based on conditional criterion according to the color of mood light that the determined content character of subregion and global area is controlled the emission of said one or more light sources.

10. atmosphere illuminator according to claim 1, wherein light source places the trailing flank of the peripheral or display unit of display unit, and wherein the field of illumination visually seen of beholder at least in part around display screen.

11. the controller (9) of the color of the mood light of an emission that is used to control the atmosphere illuminator; This controller is operably connected to this atmosphere illuminator; This atmosphere illuminator comprises one or more light sources, and (4-7,15-17), this controller comprises or communication link is received

Content tokenizer (12), it adjusts the subregion of the display screen that is used to confirm to be associated with the atmosphere illuminator and the content character of global area;

Its middle controller is adapted to the color of mood light of controlling the emission of said one or more light sources according to the determined content character of subregion and global area.

12. a display unit (1), it comprises mood light as claimed in claim 1 system.

13. a display unit according to claim 8 (1), wherein display unit is selected from following group: LCD device, plasma device, Organic Light Emitting Diode (OLED) device or projection screen.

14. an operation combines the method for the atmosphere illuminator of display unit (1) use, this display unit comprises display screen (3), and this atmosphere illuminator comprises:

Adjust one or more light sources of being used to launch mood light (4-7,15-17), said one or more light sources make the field of illumination of visually seeing from the rayed beholder of its emission (8) by a kind of deployment arrangements;

This method comprises:

With the subregion of each said one or more light source related (50) to display screen;

Confirm the content character of the subregion of (51) display screen;

Confirm the content character of the global area of (52) display screen; And

According to the determined content character of subregion and global area, the color of the mood light of the emission of control (53) said one or more light sources.

15. a computer program (19), it is adapted to, and enforcement of rights requires 14 method step when operation on calculation element.

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