Abstract:
A method for controlling a host apparatus, includes steps of the followings. First, a pattern is projected to a detection region. Second, images of the detection region are captured and image information stream is generated based on the images. Third, an image information associated with the pattern is identified to be a background image information. Fourth, a currently captured image information is subtracted to the background image information to identify if an object appears in the detection region. Fifth, a motion of the identified object is determined based on a variation of the pattern reflected from the identified object to generate a control instruction to the host apparatus. A host apparatus, an interaction control system and a method for detecting a motion of an object are also provided.

Description:
FIELD OF THE INVENTION 
     The present invention relates to control systems, and particularly to an interaction control system. 
     BACKGROUND OF THE INVENTION 
       FIG. 1  is a block diagram of a conventional interaction control system. Referring to  FIG. 1 , a conventional interaction control system  100  includes a light source module  102 , a hand-held controller  104  and a host apparatus  106 . The light source module  102  provides a plurality of point light sources for projecting light to the hand-held controller  104 . Wherein, the point light sources of the light source module  102  are arranged in a line. 
     The hand-held controller  104  has an image sensor  112 , e.g., a charge-coupled device (CCD) capable of receiving the light from the light source module  102 . With this configuration, when the image sensor  112  receives the light from the light source module  102 , a movement track of the hand-held controller  104  can be detected according to variation of spot size and movement direction of the point light sources on the image sensor  112 . In addition, in order to obtain a movement speed of the hand-held controller  104 , an accelerometer is usually configured in the hand-held controller  104 . 
       FIG. 2  is a block diagram of another conventional interaction control system. Referring to  FIG. 2 , another conventional interaction control system  200  includes a hand-held controller  202 , an image capturing device  204  and a host apparatus  206 . In addition, a point light source  212  is configured on the hand-held controller  202 . When the hand-held controller  202  moves in the space, the image sensor  204  can detect movement track of the point light source  212  and output a signal to the host apparatus  206 . Therefore, the host apparatus  206  can calculate the motion of the hand-held controller  202 . 
     In the interaction control system  200 , as only one point light source  212  is configured on the hand-held controller  202 , only when the hand-held controller  202  moves, the host apparatus  206  can detect the motion. However, when the hand-held controller  202  only rotates at one position, the host apparatus  206  cannot identify the motion. In this case, a gyroscope is needed to be configured on the hand-held controller  202 . When the hand-held controller  202  moves, the gyroscope can output a signal to the host apparatus  206 , such that the host apparatus  206  can calculate the motion of the hand-held controller  202  in the space. 
     As mentioned above, whatever conventional interaction control system needs special hand-held device, such that the conventional interaction system cannot work normally, when the hand-held device is damaged. 
     SUMMARY OF THE INVENTION 
     Accordingly, the present invention provides an interaction control system that implements the interaction operation without special hand-held device. 
     In addition, the present invention further provides a host apparatus and a method for controlling a host apparatus that allow user performing operation with interaction means. 
     Furthermore, the present invention provides a method for detecting a motion of an object that detects a movement track of the object in a space. 
     An interaction control system provided by the present invention includes a light source module, an image capturing device and an processor. The light source module projects a pattern to a detection region, and the image capturing device captures images of the detection region for generating an image information stream to the processor. Thus, the processor subtracts a currently captured image information to the background image information so as to obtain a subtracted image information for determining whether or not an object appearing in the detection region. When the processor determines the object appearing in the detection region, calculating a motion of the object based on a variation of the pattern imaged on one of surfaces of the object toward the light source, and generating a control instruction to a host apparatus. 
     From another viewpoint, a host apparatus provided by the present invention includes a control module, a light source module, an image capturing device and a processor. The light source module projects a pattern to a detection region, and the image capturing device captures images of the detection region for generating a image information stream to the processor. Thus, the processor subtracts a currently captured image information to the background image information so as to obtain a subtracted image information for determining whether or not an object appearing in the detection region. When the processor determines the object appearing in the detection region, calculating a motion of the object based on a variation of the pattern imaged on one of surfaces of the object toward the light source, and generating a control instruction to the control module so as to control the host apparatus. 
     In one embodiment of the present invention, the light source comprises a laser diode, and diffractive optical element or a micro electro mechanical system (MEMS) optical device. Wherein, the diffractive optical element or MEMS device is configured on a path of a laser beam emitted by the laser diode. Therefore, the diffractive optical element or the MEMS devices convert the laser beam into a planer light source of the said pattern. 
     From another viewpoint, a method for controlling a host apparatus provided by the present invention includes projecting a pattern to a detection region and generating an image information stream for forming a background image information of the detection region. Then, the background image information is subtracted to the currently captured image for obtaining a subtracted image information, so as to determine whether or not an object appearing in the detection region. When the object is detected in the detection region, calculating a motion of the object according a variation of the pattern imaged on one of surfaces of the object, and generating corresponding control instruction to the host apparatus so as to control the host apparatus. 
     In one embodiment of the present invention, the pattern has a plurality of parallel lines extending toward a predetermined direction. 
     From another viewpoint, a method for detecting a motion of an object provided by the invention includes projecting a pattern to a detection region and generating a image formed by reflecting the pattern from the detection region and generating an image information stream, wherein the image information stream has a plurality of pixels. Second, the currently captured image information is subtracted into a background image information for obtaining a subtracted image information. Then, absolute values of gray-scale pixels in the subtracted image information are detected. When at least one of the absolute values of the gray-scale pixels is greater than a predetermined value, determining an object appearing in the detection region where the absolute value is greater than the predetermined value. In addition, determining a movement track of the object according to a movement of the pixels having the absolute values greater than the predetermined value. 
     Since the present invention projects a pattern to a detection region, and determines a movement track of an object according to variation of the pattern imaged on one of surfaces of an object in the detection region, the present invention implements interaction control technology without special hand-held device. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above objects and advantages of the present invention will become more readily apparent to those ordinarily skilled in the art after reviewing the following detailed description and accompanying drawings, in which: 
         FIG. 1  is a block diagram of a conventional interaction control system. 
         FIG. 2  is a block diagram of another conventional interaction control system. 
         FIG. 3  is a schematic view of an interaction control system in accordance with a preferred embodiment of the present invention. 
         FIG. 4  shows a pattern projected by a light source module of the interaction control system of  FIG. 3 . 
         FIG. 5  shows a pixel region in a subtracted image information associated with the pattern of  FIG. 4 , wherein the absolute values of the gray-scale pixel region are greater than a predetermined value. 
         FIG. 6A  shows the pixel region of  FIG. 5  moves from right to left. 
         FIG. 6B  shows the pixel region of  FIG. 5  moves from left to right. 
         FIG. 7  shows line width of the pixel region of  FIG. 5  is increased. 
         FIG. 8  is a block diagram of a control module in accordance with a preferred embodiment of the present invention. 
         FIG. 9  is flow chart of a method for controlling a host apparatus in accordance with a preferred embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     The present invention will now be described more specifically with reference to the following embodiments. It is to be noted that the following descriptions of preferred embodiments of this invention are presented herein for purpose of illustration and description only. It is not intended to be exhaustive or to be limited to the precise form disclosed. 
       FIG. 3  is a schematic view of a host apparatus in accordance with a preferred embodiment of the present invention. Referring to  FIG. 3 , in the present embodiment, a host apparatus  300 , e.g., a computer system or a game machine includes an interaction control system  302  and a control module  304 . The interaction control system  302  includes a light source module  312 , an image capturing device  314  and a processor  316 . Wherein, the light source  312  is capable of projecting a pattern to a detection region A 1 . Referring to  FIG. 4 , in the present embodiment, the pattern has a plurality of parallel lines extending toward a predetermined direction. 
     Referring again to  FIG. 3 , in the present embodiment, the light source module  312  includes a laser diode  322  and a diffractive optical element  324 . In other embodiments, the diffractive optical element  324  can be replaced by a MEMS optical device. When a laser beam  326  reach the diffractive optical element  324 , the laser beam  326  is diffracted in the thereby so as to generate the pattern, as shown in  FIG. 4 . Then, the pattern is projected to the detection region A 1  by the light source module  312 . 
     In addition, the image capturing device  314  may be a CCD, a complementary metal-oxide-semiconductor (CMOS) device or a video camera. The image capturing device  314  is capable of capturing images of the detection region A 1 , and outputting an image information stream to the processor  316 . In the embodiment, the processor  316  may be a single chip, an embedded system, a central processing unit, a computer system or an application software. When the processor  316  receives the image formation IMG streaming, and determines the image formation IMG remaining unchanged in a predetermined time, the processor  316  would identify the image formation IMG to be a background image information. Meanwhile, the processor  316  will save the background image information. 
     After getting the background image information, the processor  316  can determine whether or not an object  330  appearing in the detection region A 1  by subtracting a currently captured image information IMG to the background image information. When the processor  316  determines the object  330  appearing in the detection region A 1 , the processor  316  can calculate a motion of the object  330  according to a variation of the pattern imaged from one of surfaces of the object  330  toward the light source module  312 , and generate corresponding control instruction INS to the control module  304 . 
     In detail, the image information IMG has a plurality of pixels, if the image information IMG is the same as the background image information, i.e., no object appears in the detection region A 1 , such that absolute value of the gray scale of each pixel in a subtracted image information will be less than a predetermined value. In contrast, if at least one absolute value of the gray scale of a pixel in a subtracted image information is greater than the predetermined value, example, as the pixel region  502  shown in  FIG. 5 , it can be determined that the object  330  appears in the pixel region  502 . 
     The processor  316  can determine a motion of the object  330  according to movements of the pixel region  502  in the subtracted image information wherein the absolute vales of the gray scale of the pixels are greater than the predetermined value. For example, in  FIG. 6A , the pixel region  502  moves from right to left, and in  FIG. 6B , the pixel region  502  moves from left to right. The processor  316  can output corresponding control instruction INS to the control module  304 . 
     In addition, referring to  FIG. 7 , if it is found that the line width of the pixel region  502  becomes thicker, it can be determined that the object  330  is closer to a reference point O as shown in  FIG. 3 . Meanwhile, the processor  316  can output corresponding control instruction INS to the control module  304 . In contrast, when the object  330  is away from the reference point O, the line width of the pixel region  502  becomes thinner. 
     When the control module  304  receives the control instruction INS, the control module  304  controls operations of the host apparatus  300  according to the control instruction INS.  FIG. 8  shows a block diagram of a control module in accordance with a preferred embodiment of the present invention. For one person in the art, it is known that the  FIG. 8  only shows a structure of the control module, and is not a limitation of the spirit of present invention. 
     Referring to  FIG. 8 , the control module  304  includes a storing unit  802 , a chip module  804  and a central processing unit  806 . The storing unit  802  may be a non-volatile memory, e.g., a flash memory. In other embodiments, the storing unit  802  may be a hard disk drive. In the storing unit  802 , an operation system (OS)  812  and an application program (AP)  814  can be installed herein. 
     In addition, the chip module  804  can be coupled to a transmission interface module  808 , and the transmission interface module  808  can be linked to the processor  316  to receive the control instruction INS. In other embodiments, the transmission interface module  808  may be linked to the processor  316  by a bus interface or a universal interface. In further other embodiments, the transmission interface module  808  may be linked to the processor  316  by a network, such as an Internet or a local area network (LAN). 
     When the processor  316  outputs the control instruction INS to the control module  304 , the processor  316  transmits the control instruction INS to the transmission interface module  808 . At this time, the chip module  804  can get the control instruction INS via the transmission interface module  808  and give the control instruction INS to the operation system  812  and the application program  814 . Then, the central processing unit  806  can go along corresponding calculations and actions according to operation of the operation system  812  based on the control instruction INS, thus controlling the host apparatus  300  to work. 
       FIG. 9  is a flow chart of a method for controlling a host apparatus in accordance with a preferred embodiment of the present invention. Referring to  FIG. 9 , first, as shown in step S 902 , a pattern is projected to a detection region. Secondly, as shown in step S 904 , the images of the detection region are captured for generating an image information stream. Then, go to step S 906 , a background image information of the detection region is formed. Next, go to step S 908 , a subtracted image information is obtained by subtracting a currently captured image information to the background image information for determining whether or not an object appearing in the detection region. When the object appears in the detection region, go to step S 910 , a motion of the object is calculated based on a variation of the pattern imaged on one of surfaces of the object. 
     In more detail for step S 910 , it includes the step S 912  that is used to determine whether or not any of image intensity of pixels, such as absolute values of the gray scale of the pixels, is greater than a predetermined value in the subtracted image information. When at least one of absolute values of a gray scale of the pixels is greater than the predetermined value in the subtracted image information, i.e., it is “Yes” in the decision of the step S 912 , then go to step S 914 , it can be determined that the object appears in the detection region. At this time, go to step S 916 , a movement track of the object in the space can be determined by detecting motions of the pixel region having the absolute values of the gray scale greater than the determined value in the subtracted image information, and a corresponding control instruction is generated to the host apparatus so as to control the host apparatus to work. 
     Concluded from the above description, in the present invention, a motion of an object in a detection region is determined based on a variation of the pattern projected by a light source module and reflected by a surface of the object. According to the present invention, a hardware cost is reduced. 
     While the invention has been described in terms of what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention needs not be limited to the disclosed embodiment. On the contrary, it is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims which are to be accorded with the broadest interpretation so as to encompass all such modifications and similar structures.