Abstract:
An image capture system is provided. The image capture system for capturing an image of an object includes a light emitting module, a lens, a base unit and a filter unit. The light emitting module provides a plurality of light beams to form a reference area. The base unit includes a light sensor corresponding to the lens. The filter unit includes at least one visible light passing portion and at least one invisible light passing portion. The filter unit is driven to position one of the visible light passing portion and the invisible light passing portion between the lens and the light sensor. The actual size of the object can be estimated via the reference area.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This Application claims priority of Taiwan Patent Application No. 097104650, filed on Feb. 5, 2008, the entirety of which is incorporated by reference herein. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to an image capture system, and in particular, to an image capture system which can generate a label mark and a method of capturing a labeled image. 
     2. Description of the Related Art 
     When capturing an image with a camera, the object being captured is measured by placing a scale (for example: a pen, a coin or a ruler) adjacent thereto for reference, such that the scale and the object can be compared in order to get a better understanding about the size of the object. 
     However, if the object being captured is a column, a beam or strips on a wall for a construction site, and the size of the object is also desired, it is difficult for a photographer to capture an image by using a scale, such as a pen, a coin or a ruler, adjacent thereto for reference, as it may not be easy to get close to the object. 
     Therefore, if a camera can provide a scale for reference around an object or near an object, the above problems concerning difficulties in getting close to an object or using a scale adjacent thereto for reference, can be mitigated. Thus, improving convenience of image capture devices. 
     BRIEF SUMMARY OF THE INVENTION 
     The invention provides an image capture system having the ability to provide a scale for reference. 
     The invention also provides a method for capturing a labeled image. 
     Accordingly, the image capture system captures an image of an object. The image capture system comprises a light emitting module, a lens, a base unit, a switch mechanism and an image processing unit. 
     The light emitting module projects a plurality of infrared light beams. The infrared light beams form a reference area. The lens, having an optical axis, receives the infrared light beams reflected from the object and visible light beam emitted by the object. The base unit comprises a light sensor corresponding to the optical axis of the lens, transforming incident optical signals into an image signal. 
     The switch mechanism comprises a filter unit and a switch driver. The filter unit comprises at least one visible light passing portion and at least one invisible light passing portion. The switch driver drives the filter unit to position one of the visible light passing portion and the invisible light passing portion between the lens and the light sensor. The image processing unit integrates the image signal from the light sensor. 
     The method of capturing a labeled image comprises the following steps: The light emitting module projects a plurality of infrared light beams, and the infrared light beams form a reference area. The visible light passing portion is placed between the light sensor and the lens, and the light sensor captures light beams passing through the visible light passing portion. The invisible light passing portion is placed between the light sensor and the lens, and the light sensor captures light beams passing through the invisible light passing portion. An image processing unit integrates image signals captured by the light sensor. 
     The invention is advantageous in that the emission of the infrared light beam of the light emitting module provides a reference area adjacent to an object as a scale to help estimate the size of the object. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein: 
         FIG. 1  is a schematic view of an embodiment of an image capture system of the invention applied in a camera; 
         FIG. 2  is an assembled view of the embodiment of the invention; 
         FIG. 3  is an exploded view of the embodiment of the invention; 
         FIG. 4  is another exploded view of the embodiment of the invention; 
         FIG. 5  is a diagram showing formation of the image capture system; 
         FIG. 6  is a schematic view showing reflected first infrared light beams, second infrared light beams and visible light beam emitted by an object displayed on an image display unit; and 
         FIG. 7  is a flow chart showing a method for capturing a labeled image by the image capture system of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings which show by way of illustration, four specific embodiments in which the invention may be practiced. 
     Referring to  FIGS. 1 ,  3  and  5 , a preferred embodiment of an image capture system of the invention is shown. In the embodiment, the image capture system is a camera  100  for capturing an object S (as shown in  FIG. 6 ) for being shot. The image capture device  100  comprises a lens  1 , a base unit  2 , a light emitting module  3 , a switch mechanism  4 , a digital signal processor  5 , an image display unit  6  and a housing  7 . The housing  7  is eliminated in  FIGS. 2 ,  3  and  4  for clarity. In the embodiment, the image display unit  6  is a liquid crystal display (LCD). 
     The lens  1 , having an optical axis C, is assembled on the base unit  2 . The base unit  2  comprises a main body  21  for assembling the lens  1  and a light sensor  23  corresponding to the optical axis C, which is assembled on the main body  21  by a bottom portion  22 . The light sensor  23  captures optical signals from the lens  1 , and transforms the incident optical signals into image signals. In the embodiment, the light sensor  23  is a charge-coupled device (CCD), a complementary metal oxide semiconductor (CMOS) or other solid state elements having the ability to transform the optical signal into the image signal. 
     As shown in  FIGS. 2 ,  4  and  6 , the light emitting module  3  projects a plurality of light beams. In the embodiment, the light beams refer to infrared light beams, but it is not limited thereto. The infrared light beams emitted by the light emitting module  3  form a reference area D on a plane. In detail, the light emitting module  3  comprises two first emitting devices  31 , two second emitting devices  32  and a control button  33  used to control the first and second emitting devices  31 ,  32 . The two first emitting devices  31  are assembled on the main body  21  of the base unit  2 , respectively located on the left and right sides of the lens  1 . The two second emitting devices  32  are also assembled on the main body  21  of the base unit  2 , respectively located on upper and bottom sides of the lens  1 . 
     The two first emitting devices  31  project two first infrared light beams  311 , and straight line beams in parallel to each other, forming a first length L 1  therebetween as a scale for reference. The two second emitting devices  32  project two second infrared light beams  321 , and straight line beams in parallel to each other, forming a second length L 2  therebetween as a scale for reference. The reference area D comprises the first length L 1  and the second length L 2 . When the control button  33  is pressed, the first and second emitting devices  31 ,  32  project the first and second infrared light beams  311 ,  321 , respectively. The first and second infrared light beams  311 ,  321  emitted to the object S, and are reflected to the lens  1 . The lens  1  receives the reflected first and second infrared light beams  311 ,  321  and the visible light beam from the object S. 
     In the embodiment, the first, second infrared light beams  311 ,  321  are line beams projected in a direction that is parallel with the optical axis C, and form a double-lined crisscross (#) after traveling a determined distance. For example, the first length L 1  and the second length L 2  are both 8 cm, which means the reference area D (as shown in dotted line of  FIG. 6 ) formed in the center of the double-lined crisscross is a square with 8 cm-long sides. However, the present invention is not limited thereto. 
     The switch mechanism  4  comprises a filter unit  41 , a switch driver  42  and a rack  43 . The filter unit  41  is a disk-shaped color wheel comprising two visible light passing portions  411  and two invisible light passing portions  412 , alternately disposed with equal angles (90 degree). 
     The switch driver  42 , assembled to the main body  21  by the rack  43 , drives the filter unit  41  to rotate, positioning one of the visible light passing portions  411  and the invisible light passing portions  412  between the lens  1  and the light sensor  23 . 
     Accordingly, a complex optical signal enters the image capture device  100  via the lens  1 . The visible light passing portion  411  or the invisible light passing portion  412  is switched to be positioned between the lens  1  and the light sensor  23 , allowing the visible light passing portion  411  to absorb or eliminate the invisible infrared light beams or stray light beams, or allowing the invisible light passing portion  412  to absorb or eliminate the visible light beam, such that the light sensor  23  can capture the image of the object S, or detect the infrared light beams reflected from the exterior. In the embodiment, the visible light passing portions  411  or the invisible light passing portions  412  are made of an optical coating or an optical member, but it is not limited thereto. 
     Referring to  FIG. 5 , the digital signal processor (DSP), controlling the operation of the components within the image capture device  100 , comprises an image processing unit  51 . The image processing unit  51  processes an image signal from the light sensor  23 , stores the image signal in an image cache  52 , and integrates the visible light beam and the infrared light beams into an image shown in the image display unit  6 . Thus, a user can estimate the actual size of the object S with the naked eye by comparing it with the reference area D. 
     As shown in  FIGS. 4 ,  6  and  7 , a method for capturing a labeled image according to an embodiment of the invention by using the above described image capture device  100  comprises the following steps: 
     Step one: The object S is focused with the lens  1  of the image capture device  100 . The control button  33  of the light emitting module  3  is pressed, activating the first and second emitting devices  31 ,  32  to emit the first and second infrared light beams  311 ,  321 . The first and second infrared light beams  311 ,  321  form a double-lined crisscross (#) after traveling a determined distance in order to frame a reference area D. The first length D 1  of the reference area D is formed between the first infrared light beams  311 , and the second length D 2  of the reference area D is formed between the second infrared light beams  321 . 
     Step two: The switch driver  42  of the switch mechanism  4  drives the filter unit  41  to rotate, aligning one of the visible light passing portions  411  on the optical axis C, between the light sensor  23  and the lens  1 . Meanwhile, the visible light beam of the object S and the first and second reflected infrared light beams form a complex optical signal which enters the lens  1 . However, only the visible light beam passes the visible light passing portion  411 , and the reflected infrared light beams are absorbed or eliminated by the visible light passing portion  411 . Next, the light sensor  23  captures the visible light beam passing through the visible light passing portion  411  and transforms the visible light beam into a first image signal which in stored in an image cache  52 . 
     Step three: The switch driver  42  of the switch mechanism  4  drives the filter unit  41  to rotate ninety degrees, aligning one of the invisible light passing portions  412  on the optical axis C, between the light sensor  23  and the lens  1 . Meanwhile, only the infrared light beams pass the invisible light passing portion  412 , and the visible light beam is absorbed or eliminated by the invisible light passing portion  412 . Next, the light sensor  23  captures the infrared light beams passing through the invisible light passing portion  412  and transforms the infrared light beams into a second image signal which is stored in an image cache  52 . 
     Step four: The image processing unit  51  processes the first and second image signals stored in the image cache  52  and integrates them into an image. 
     Step five: Referring to  FIG. 6 , the image signals resulting from the above steps are outputted to the image display unit  6 . Because the first and second image signals have already been integrated into the image, the object S and the labeled image, formed by the first and second infrared light beams  311 ,  321 , is presented in the image simultaneously. Therefore, a user can estimate the actual size of the object S with the naked eye by comparing the object S with the reference area D. 
     It should be noted that after the light sensor  23  captures the infrared light beams which are invisible, the second image signal generates a gray-level label via digital conversion and signal processing. In detail, in the embodiment, the double-lined crisscross (#) is first generated in gray level, and is then configured with a specific color on the first image signal to form the image via setting of the image capture device  100  or via the user preference. 
     In the above steps, the infrared light beams are eliminated (in step two), and the visible light beam is captured (in step three) before the visible light beam is eliminated (in step four) and the infrared light beams are captured (in step five). However, one skilled in the art can also eliminate the visible light beam and capture the infrared light beams before eliminating the infrared light beams and capturing the visible light beam, and the invention is not limited thereto. 
     The advantageous of the present invention are described as follows. 
     By utilizing the light emitting module  3 , the first and second infrared light beams  311 ,  321  are emitted to form a reference area D near the object S, replacing the conventional method, wherein a scale is positioned beside the object S as reference. Thus, difficulties in getting close to an object S or using a scale adjacent thereto for reference are mitigated. Additionally, convenience of an image capture device is improved. 
     Note that the present invention comprises the following embodiments. 
     First, in the embodiment of the invention, the filter unit  41  is a disc shaped color filter, and the switch driver  42  is a motor or a step motor driving the filter unit  41  to rotate. However, the filter unit  41  can also be a rectangular structure comprising a visible light passing portion  411  and a invisible light passing unit  412 , and the switch driver  42  can also be a magnetic valve to switch the filter unit  41  on the optical axis C, between the lens  1  and the light sensor  23 , such that the switch mechanism  4  fulfills the same function as the filter switch. 
     Second, in the embodiment of the invention, the spot beams emitted by laser sources within the first and second emitting devices  31 ,  32  are changed into line beams by the cylindrical mirrors (not shown) to form the first and second infrared light beams  311 ,  321 . However, if the cylindrical mirror is not present, the first and second infrared light beams  311 ,  321  can be emitted to be spot beams (not shown). Meanwhile, the distance between the two spots of the first infrared light beam  311  is the first length L 1 , and the distance between the two spots of the second infrared light beam  321  is the second length L 2 , wherein the function to provide a scale for reference can be fulfilled. 
     Third, in the embodiment of the invention, the light emitting module  3  utilizes the two first emitting devices  31 , and the two second emitting devices  32  to emit the first and second infrared light beams  311 ,  321 . However, it is also possible to comprises only two emitting devices or three emitting devices aligned in an L shape (not shown) for emitting two or three line beams or spot beams, wherein the function to provide a scale for reference can be fulfilled. 
     While the invention has been described by way of example and in terms of preferred embodiment, it is to be understood that the invention is not limited thereto. To the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.