AMBIENT LIGHT SENSING DEVICE AND METHOD, AND INTERACTIVE DEVICE USING SAME
The invention provides an ambient light sensing device which receives at least one visible light image sensed by an image sensor. The ambient light sensing device includes an image sampling unit and an analyzing unit. The image sampling unit divides the visible light image into plural image blocks, extracts at least one sample data in each image block, and generates a comparison data according to a difference between the sample data extracted at different time points. The analyzing unit analyzes the comparison data and generates an output analysis signal accordingly.
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The present invention claims priority to TW 101127676, filed on Aug. 1, 2012.
BACKGROUND OF THE INVENTION1. Field of Invention
The present invention relates to an ambient light sensing device and method, especially an ambient light sensing device and method which divide a visible light image into plural image blocks and respectively sample and analyze data in the image blocks to generate an output analysis signal. An interactive device using the ambient light sensing device is also provided by the present invention.
2. Description of Related Art
An ambient light sensor is used for sensing ambient light and analyzing the status of the ambient light. In order to simulate the effect of human eyes in response to light of visible wavelength, the ambient light sensor usually includes a film coating, a digital to analog converter, and a power amplifier, etc. A proximity sensor also senses light, but its function is to detect a distance. The proximity sensor usually includes an infrared light source; the infrared light source projects light, and the proximity sensor receives light reflected from an object to determine a distance from the object. An interactive device is often equipped with various different kinds of sensing devices according to different requirements.
However, to equip multiple sensing devices in an interactive device, especially the proximity sensor which requires an additional infrared light source, increases the cost, power consumption and complexity. Furthermore, when the interactive device is a portable electronic device, it will be more convenient if the portable electronic device can be controlled by more ways (for example, shaking the portable electronic device to input a command) but does not require additional components to increase its complexity, which will make the interactive device more competitive.
Therefore, it is desired to provide an interactive device with reduced cost, power consumption and complexity, and more ways of control.
SUMMARY OF THE INVENTIONThe present invention provides an ambient light sensing device and method, and an interactive device using the ambient light sensing device, which can reduce the cost and complexity and provide more ways of control.
According to the above and other objectives, the present invention provides an ambient light sensing device for receiving a visible light image generated from an image sensor. The ambient light sensing device includes an image sampling unit and an analyzing unit. The image sampling unit divides the visible light image into plural image blocks, extracts at least one sample data in each image block, and generates a comparison data according to a difference between the sample data extracted at different time points. The analyzing unit analyzes the comparison data and generates an output analysis signal.
The present invention also provides an interactive device, which includes: an image sensor, for providing a camera function for the interactive device to generate an image according to ambient light; and an ambient light sensing device, for extracting at least one sample data in the image, generating a comparison data according to a difference between the sample data extracted at different time points, and analyzing the comparison data to generate an output analysis signal accordingly.
The present invention also provides a method of sensing ambient light, which includes: obtaining an image according to ambient light by an image sensor provided in an interactive device for a camera function; extracting at least one sample data in the image; generating a comparison data according to a difference between the sample data extracted at different time points; and analyzing the comparison data to generate an output analysis signal accordingly.
In a preferable embodiment of the present invention, the visible light image is divided into plural image blocks of a uniform size or of sizes in proportion to one another.
In a preferable embodiment of the present invention, the visible light image includes plural pixel data and each pixel data includes plural sub-pixel data. The sample data is generated according to brightness, color temperature, contrast, image pattern, a number or shape of a group of pixels having a predefined color or meeting a predefined condition, or a number or shape of a group of sub-pixels having a predefined color or meeting a predefined condition. The sub-pixels having a predefined color for example are green sub-pixels.
In a preferable embodiment of the present invention, the output analysis signal is generated according to the comparison data and a status of the interactive device. The output analysis signal includes one or more of the followings: a flip signal, a proximity signal, an ambient brightness signal, a gesture signal, a device motion signal, and a device shake signal.
In a preferable embodiment of the present invention, a function of the interactive device can be performed according to the output analysis signal.
The objectives, technical details, features, and effects of the present invention will be better understood with regard to the detailed description of the embodiments below, with reference to the drawings.
The drawings as referred to throughout the description of the present invention are for illustrative purpose only, but not drawn according to actual scale. The orientation such as: up, down, left, or right is for reference to the drawings only.
The ambient light sensing device of the present invention can be used in various interactive devices such as a touch pad, a touch panel, a mobile phone, a personal digital assistant (PDA), a laptop computer, a tablet computer, or the like.
In this embodiment, the ambient light sensing device 20 includes an image sampling unit 21 and an analyzing unit 22. If the image sensor S is a sensor already provided in the interactive device, then the image sensor S is usually for providing a camera function (photo taking or video recording) and it generates visible light image (however the present invention is not limited to this; the image sensor S also can be one which generates invisible light image such as infrared image). The image sampling unit 21 divides the visible light image (S2,
Referring to
Referring to
The sample data for example can be a center value, an average value, a gravity value, a highest value, etc. of an image block, as a representing value of the image block. The comparison data can be a function based on an operation of a previous sample data and a later sample data, wherein a simplest example is a difference between sample data extracted at different time points. The “value” for calculation can be brightness or other parameters that can be obtained.
In one embodiment of the ambient light sensing device 20 according to the present invention, the analyzing unit 22 analyzes the sample data and generates an output analysis signal. Or in another embodiment, besides the sample data, the analyzing unit 22 can refer to other information (for example but not limited to an operating status, time, gravity status, acceleration, or angular velocity of the interactive device) and generate the output analysis signal. The output analysis signal may include one or more of the followings: a flip signal, a proximity signal, an ambient brightness signal, a gesture signal, a device motion signal, and a device shake signal, wherein which of the above is the output analysis signal can be decided with reference to the status of the interactive device. In detail, the flip signal indicates whether the interactive device equipped with the ambient light sensing device 20 flips or not. The proximity signal indicates whether an object is nearby the interactive device. The ambient brightness signal represents a sensing result on ambient light brightness. The gesture signal indicates whether a user makes a specific gesture toward or with reference to the interactive device. The device motion signal indicates a moving direction and/or displacement of the interactive device. The device shaking signal indicates whether the interactive device is shaking. All of these signals can provide a user with information or provide the user with possible ways to control the interactive device.
furthermore specifically, the analyzing unit 22 receives the comparison data from the image sampling unit 21 and determines whether the dynamic range of the comparison data changes or not, such as changing from a bright range to a dark range or vice versa, wherein the threshold between the bright range and dark range can be set according to implementation needs. For example, when the interactive device is a mobile phone or a tablet computer, and the analyzing unit 22 analyzes the comparison data for a purpose to judge whether the mobile phone or tablet computer flips or not (i.e., the output analysis signal is the flip signal), because the mobile phone may not be completely shaded when it flips while the tablet computer can be better shaded than the mobile phone, the threshold of the dark range for determining whether the mobile phone is flipped should be less stringent than the tablet computer. For another example, if the interactive device is a mobile phone, and the analyzing unit 22 analyzes the comparison data for a purpose to determine whether the mobile phone flips or closes to a human ear (i.e., the output analysis signal is a flip signal or a proximity signal), because the mobile is not completely shaded and is less shaded as it flips, the threshold of dark range for determining whether the mobile phone closes to a human ear should be less stringent than the threshold of dark range for determining whether the mobile phone flips. Therefore, the threshold setting for dark and bright ranges should depend on the implementation needs. In addition, the requirement of the sensitivity to the dark range is usually higher than the requirement of the sensitivity to the bright range, so in one embodiment, the bright and dark ranges can be scaled by a logarithmic function.
An example of how the output analysis signal generated by the analyzing unit 22 can help a user to control the interactive device is now described. Referring to
More specifically, when the interactive device is a mobile phone and its operating status is ringing, the output analysis signal for example can be a flip signal and this for example means that the user intends to change the ringtone to silent mode or the user refuses to answer the call. When the mobile phone is in a conversation mode, the output analysis signal for example can be a proximity signal indicating whether the user's face is closing to the mobile phone or not. If the user's face is closing to the mobile phone, the brightness of the display can be decreased or the display can be shut down to save unnecessary power consumption. For another example, when the display is functioning, the output analysis signal can be an ambient light signal indicating the ambient brightness, and the brightness of the display can be adjusted according to the ambient light signal; for example, the brightness of the display can be decreased in high brightness environment to save power consumption, and the brightness of the display can be increased in low brightness environment for better display effect.
It is preferable but not necessary for the output analysis signal to be generated in correlation to the operating status. The output analysis signal can be generated by the analyzing unit 22 independent of the operating status of the interactive device D.
The judgment in the aforementioned embodiments is based on brightness; however, the sample data needs not be related to the brightness of the whole image or the block. In another embodiment, the image sampling unit 21 can extract at least one image index in the visible light image to be the sample data, and the image sampling unit 21 can generate a comparison data according to the difference between the sample data extracted at different time points. The image index can be generated according to one or more of: color temperature, contrast, image pattern, a number or shape of a group of pixels having a predefined color or meeting a predefined condition, or a number or shape of a group of sub-pixels having a predefined color or meeting a predefined condition, and the aforementioned brightness. Basically, the image index can be generated by calculating one or plural representative pixels/sub-pixels in the whole or a part of the image with any suitable method, and the calculation result can be the sample data. The comparison data can be generated from the image indices, and the analyzing unit 22 can generate the output analysis signal according to the comparison data, for example according to methods described in the above embodiments.
The present invention has been described in considerable detail with reference to certain preferred embodiments thereof. It should be understood that the description is for illustrative purpose, not for limiting the scope of the present invention. Those skilled in this art can readily conceive variations and modifications within the spirit of the present invention. For example, the exposure time of the image sensor as it captures an image may affect the analysis of the analyzing unit as it analyzes the comparison data, so the exposure time is preferably set in a proper range, or the analysis can be correlated to the exposure time. For another example, when a low resolution image sensor is used, the number of samples taken from an image is preferably more than a case where a high resolution image sensor is used, so that the analysis is more accurate. The present invention is not limited to the application in a mobile phone; it can be applied to any other kind of portable electronic device or a larger size electronic device. An embodiment or a claim of the present invention does not need to achieve all the objectives or advantages of the present invention. The title and abstract are provided for assisting searches but not for limiting the scope of the present invention.
Claims
1. An ambient light sensing device for receiving at least one visible light image sensed by an image sensor, comprising:
- an image sampling unit, for dividing the visible light image into a plurality of image blocks, extracting at least one sample data in each image block, and generating a comparison data according to a difference between the sample data extracted at different time points; and
- an analyzing unit, for analyzing the comparison data and generating an output analysis signal accordingly.
2. The ambient light sensing device of claim 1, wherein the visible light image is divided into the plurality of image blocks of a uniform size or of sizes in proportion to one another.
3. The ambient light sensing device of claim 1, wherein the sample data includes at least one green sub-pixel data, and the image sampling unit generates the comparison data according to the green sub-pixel data.
4. The ambient light sensing device of claim 1, wherein the sample data is generated according to brightness.
5. The ambient light sensing device of claim 1, wherein the visible light image includes a plurality of pixel data and each pixel data includes a plurality of sub-pixel data, and the sample data is generated according to brightness, color temperature, contrast, image pattern, a number or shape of a group of pixels having a predefined color or meeting a predefined condition, or a number or shape of a group of sub-pixels having a predefined color or meeting a predefined condition.
6. The ambient light sensing device of claim 1, wherein the ambient light sensing device is disposed in an interactive device and the analyzing unit generates the output analysis signal according to the comparison data and a status of the interactive device.
7. The ambient light sensing device of claim 1, wherein the output analysis signal includes one or more of the followings:
- a flip signal, a proximity signal, an ambient brightness signal, a gesture signal, a device motion signal, and a device shaking signal.
8. An interactive device, comprising:
- an image sensor, for providing a camera function for the interactive device to generate an image according to ambient light; and
- an ambient light sensing device, for extracting at least one sample data in the image, generating a comparison data according to a difference between the sample data extracted at different time points, and analyzing the comparison data to generate an output analysis signal accordingly.
9. The interactive device of claim 8, wherein the ambient light sensing device divides the image into a plurality of image blocks and extracting at least one sample data in each image block.
10. The interactive device of claim 8, wherein the image includes a plurality of pixel data and each pixel data includes a plurality of sub-pixel data, and the sample data is generated according to brightness, color temperature, contrast, image pattern, a number or shape of a group of pixels having a predefined color or meeting a predefined condition, or a number or shape of a group of sub-pixels having a predefined color or meeting a predefined condition.
11. The interactive device of claim 9, wherein the image includes a plurality of pixel data and each pixel data includes a plurality of sub-pixel data, and the sample data is generated according to brightness, color temperature, contrast, image pattern, a number or shape of a group of pixels having a predefined color or meeting a predefined condition, or a number or shape of a group of sub-pixels having a predefined color or meeting a predefined condition.
12. The interactive device of claim 8, wherein the image sensor includes a plurality of pixels and each pixel includes a plurality of sub-pixels for sensing a visible light image, and wherein the sample data includes at least one sub-pixel data.
13. The interactive device of claim 8, wherein the ambient light sensing device generates the output analysis signal according to the comparison data and a status of the interactive device.
14. The interactive device of claim 8, wherein the output analysis signal includes one or more of the followings: a flip signal, a proximity signal, an ambient brightness signal, a gesture signal, a device motion signal, and a device shaking signal.
15. A method of sensing ambient light, comprising:
- obtaining an image according to ambient light by an image sensor provided in an interactive device for a camera function;
- extracting at least one sample data in the image;
- generating a comparison data according to a difference between the sample data extracted at different time points; and
- analyzing the comparison data to generate an output analysis signal accordingly.
16. The method of claim 15, wherein the step of extracting at least one sample data in the image includes:
- dividing the image into a plurality of image blocks and extracting at least one sample data in each image block.
17. The method of claim 15, wherein the image includes a plurality of pixel data and each pixel data includes a plurality of sub-pixel data, and the sample data is generated according to brightness, color temperature, contrast, image pattern, a number or shape of a group of pixels having a predefined color or meeting a predefined condition, or a number or shape of a group of sub-pixels having a predefined color or meeting a predefined condition.
18. The method of claim 15, wherein the step of analyzing the comparison data to generate an output analysis signal includes:
- generating the output analysis signal according to the comparison data and a status of the interactive device.
19. The method of claim 15, wherein the output analysis signal includes one or more of the followings: a flip signal, a proximity signal, an ambient brightness signal, a gesture signal, a device motion signal, and a device shaking signal.
20. The method of claim 15, further comprising:
- performing a function of the interactive device according to the output analysis signal.
Type: Application
Filed: Jun 29, 2013
Publication Date: Feb 6, 2014
Applicant: PixArt Imaging Incorporation (Hsin-Chu)
Inventor: Chuan-Hsin Lee (Hsin-Chu)
Application Number: 13/931,878
International Classification: G06F 3/03 (20060101); G06K 9/46 (20060101);