Patent Publication Number: US-7712903-B2

Title: Remote instruction system, remote instruction method and program product for remote instruction

Description:
BACKGROUND 
   1. Technical Field 
   This invention generally relates to a remote instruction system and a remote instruction method. 
   2. Related Art 
   In a remote conference system, various instructions have to be given to a real object side from a remote side. As an example of the remote instruction system where an instruction can be given from the remote side to the real object side, there is known a technique of projecting an annotation image determined on a remote terminal on the basis of a captured image onto a target object from a projector on the real object side, while the target object existent on the real world side is being captured by a camcorder and such captured image being transmitted to the remote terminal. 
   SUMMARY 
   An aspect of the invention provides a remote instruction system comprising a control portion. The control portion transmits an image captured by an image capturing portion provided for capturing the image of a subject to a remote terminal, and controls a projection portion to project an annotation image onto the subject according to an instruction issued from the remote terminal on the basis of the image captured. The control portion measures a reflection characteristic of a surface of the subject on the basis of the image captured, and converts a color of the annotation image to be projected onto the subject on the basis of a comparison result between the color of the annotation image instructed by the remote terminal and the reflection characteristic of the surface of the subject to project the annotation image onto the subject. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Embodiments of the present invention will be described in detail based on the following figures, wherein: 
       FIG. 1  is a configuration diagram illustrating an exemplary embodiment of a remote instruction system; 
       FIG. 2  is a flowchart showing an example process on a server of a subject side apparatus; 
       FIG. 3  is a flowchart showing an example process of forming an image on a computer of a remote terminal; 
       FIG. 4  is a view illustrating an example operation on the side of the remote terminal; 
       FIG. 5  is a process flowchart showing a case where a color of an annotation image is converted and then the annotation image is projected in the remote instruction system; 
       FIG. 6A  is a view illustrating the annotation image determined on a remote terminal; 
       FIG. 6B  is a view illustrating color components (color A) of the annotation image determined on the remote terminal; 
       FIG. 7A  is a view illustrating a portion of the subject surface onto which the annotation image is to be projected; 
       FIG. 7B  is a view illustrating the color components (color B) of the subject on a portion in the image onto which the annotation image is projected; 
       FIG. 8A  is a view illustrating an annotation image in the image captured by the camcorder; 
       FIG. 8B  is a view illustrating the color components (color C) of the annotation image in the image captured by the camcorder; 
       FIG. 9  is a view illustrating the color components (color D) of the corrected annotation image; and 
       FIG. 10  is another process flowchart of a case where the color of the annotation image is converted and the annotation image is projected in the remote instruction system. 
   

   DETAILED DESCRIPTION 
   A description will now be given, with reference to the accompanying drawings, of embodiments of the present invention.  FIG. 1  is a configuration diagram illustrating an exemplary embodiment of a remote instruction system  1 . The remote instruction system  1  includes a subject side apparatus  10  and a remote terminal  100 . The subject side apparatus  10  and the remote terminal  100  are connected to each other to enable mutual communication by a network  300 . In  FIG. 1 , only one remote terminal  100  is shown, however, multiple remote terminals  100  can be connected to a server  50 , as will be discussed later, of the subject side apparatus  10  through the network  300 . 
   The subject side apparatus  10  is composed of a camcorder  20  serving as an image capturing portion, a projector  40  serving as a projection portion, the server  50  serving as a control portion, a half mirror  60 , and a rotation stage  70  serving as a relative position changing portion. The camcorder  20  is composed of a CCD camera, for example, to capture a subject (target object)  200  placed on the rotation stage  70 , while information of such captured image is being taken into the server  50 . The camcorder  20  captures an image transmitted through the half mirror  60 . 
   The projector  40  is composed of a liquid crystal projector or the like, and projects an annotation image  201  onto the subject  200 , according to an instruction given from the remote terminal  100  on the basis of a captured image. In addition, the projector  40  is arranged in such a manner that an optical system thereof is substantially aligned with an optical principal point of the camcorder  20  by the half mirror  60 . The projector  40  projects the annotation image transmitted from the server  50  onto the subject  200  through an optical system thereof and the half mirror  60 . The annotation image projected from the projector  40  is reflected by the half mirror  60  and projected onto the subject  200 . The annotation image includes any type of image such as line, character, drawing, and the like. 
   The rotation stage  70  is controlled by the server  50 , and the subject  200  placed on a top surface of the rotation stage  70  is rotated, so that the position of the subject  200  with respect to the camcorder  20  and the projector  40  is changed. The server  50  controls operations of the camcorder  20 , the projector  40 , and the rotation stage  70 , while sending and receiving various information to and from the remote terminal  100  over the network  300 . 
   The server  50  sends the image captured by the camcorder  20  to the remote terminal  100 , and projects the annotation image onto the subject  200 , according to an instruction issued by the remote terminal  100  on the basis of such captured image. The server  50  controls to change a projection position of the annotation image, which is projected by the projector  40 , in accordance with the rotation (movement) of the subject  200  placed on the rotation stage  70 . 
   The remote terminal  100  is composed of a display apparatus  110 , a computer  120 , a pointing device (mouse)  130 , and the like. The display apparatus  110  is composed of a liquid crystal display, CRT, or the like. The computer  120  is connected to the network  300 . The pointing device  130  is connected to the computer  120 . The display apparatus  110  displays an image transmitted from the subject side apparatus  10 , on a display screen thereof. The pointing device  130  is used for operating various buttons by means of a pointer on the display screen on which the captured image is being displayed, so as to create an instruction with respect to the annotation image to be projected onto the subject  200 . The pointing device  130  is also used for giving an instruction to rotate the subject  200  with the use of the rotation of the rotation stage  70 . 
   Next, operations of the remote instruction system  1  having the above-described configuration are described with reference to  FIG. 2  through  FIG. 4 .  FIG. 2  is a flowchart showing an example process on the server  50  of the subject side apparatus  10 .  FIG. 3  is a flowchart showing an example process of forming an image on the computer  120  of the remote terminal  100 .  FIG. 4  is a view illustrating an example operation on the side of the remote terminal  100 . 
   Referring now to  FIG. 2 , the server  50  of the subject side apparatus  10  starts capturing an image by means of the camcorder  20  (step S 11 ), and determines whether or not there is a connection request from the computer  120  of the remote terminal  100  (step S 12 ). If there is a connection request from the computer  120 , the server  50  transmits the image captured by the camcorder  20  to the computer  120  of the remote terminal  100  through the network  300  (step S 13 ). 
   Subsequently, the server  50  determines whether or not there is a transmission of a control signal from the computer  120  (step S 14 ). The control signal includes a drawing signal and a position control signal, the drawing signal being information on drawing of the annotation image, the position control signal being provided for rotating the rotation stage  70 . If the server  50  receives the afore-described control signal, the server  50  performs a control signal processing according to the content of the control signal (step S 15 ). 
   Meanwhile, if the server  50  does not receive the above-described control signal, the server  50  determines whether or not there is a disconnection request (step S 16 ). If there is no disconnection request, the server  50  goes back to step S 13  and transmits a newly captured image to the computer  120  of the remote terminal  100  through the network  300 . If there is a disconnection request, the server  50  stops transmitting the image captured by the camcorder  20  (step S 17 ). Then, the server  50  determines whether or not there is a process end request (step S 18 ). If there is no end request, processing goes back to step S 12  to repeat the above-described processes. If there is a process end request, processing is terminated. 
   Next, a description is given of the operation of the remote terminal  100 . Firstly, as shown in  FIG. 3 , the computer  120  of the remote terminal  100  issues a connection request to the server  50  (step S 21 ). Then, after the connection is established, for example, as shown in  FIG. 4 , the computer  120  displays the captured image being transmitted from the server  50  of the subject side apparatus  10  on a display screen  111  of the display apparatus  110  (step S 22 ). 
   Subsequently, the computer  120  determines whether or not there is an instruction on an attention region in the captured image given by an operator (step S 23 ). If there is an instruction on the attention region, the process according to the instruction is performed (step S 26 ). Specifically, if there is a region in the image being displayed onto which the operator likes to project the annotation image, the operator of the remote terminal  100  operates the pointing device  130  to move a pointer Pt on the display screen  111  and issues an instruction on the attention region, while watching the image on the display screen  111  of the display apparatus  110 , as shown in  FIG. 4 . The attention region is a region that defines a projection position onto which an annotation image DR is to be projected. At this time, the operator simultaneously issues an instruction of the information on the annotation image to be projected onto the attention region. 
   For example, it is possible to instruct graphic information such as drawn rectangle or circle, bitmap images prepared in advance, text information input from the keyboard, by operating various buttons BT or the like formed on the display screen 
   The computer  120  transmits various types of information specified at step S 26  to the server  50  as drawing information (step S 27 ). 
   Next, the computer  120  determines whether or not the operator&#39;s instruction issued from the remote terminal  100  on the basis of the image captured by the camcorder  20  has been completed (step S 28 ). If the instruction is completed, a disconnection request is issued to the server  50  (step S 29 ) and the processing is terminated. If the instruction issued by the operator of the remote terminal  100  is not completed, processing goes back to step S 22  to repeat the above-described processes. 
   Here, if the operator of the remote terminal  100  likes to rotate the subject  200 , the operator operates rotation buttons R 1  and R 2  to instruct a rotation direction and rotation amount of the rotation stage  70 , while watching the image being displayed on the display screen  111  as shown in  FIG. 4 , so that the region in the subject  200  in the captured image onto which the operator likes to project the annotation image may be displayed or a viewing location of the subject  200  may be most appropriate. The rotation buttons R 1  and R 2  are provided on the display screen  111  to rotate the rotation stage  70 . At step S 23 , if there is no instruction on the attention region (there is no instruction on the annotation image), the computer  120  determines that an instruction on the rotation of the subject  200  is to be given, and performs processing relating to the rotation of the subject  200  (step S 24 ). 
   Then, the computer  120  transmits information on the rotation mount (movement amount information), which has been obtained by the process relating to the rotation of the subject  200 , to the server  50  of the subject side apparatus  10  (step S 25 ). This rotates the rotation stage  70  and changes the rotation position of the subject  200  on the subject side apparatus  10 . A newly captured image is displayed on the display apparatus  110  of the remote terminal  100  (step S 22 ). 
   Next, a description is given of the operation of a case where the annotation image is converted according to a reflection characteristic of a subject surface and is then projected.  FIG. 5  is a process flowchart showing a case where the color of the annotation image is converted and the annotation image is then projected in the remote instruction system. The color may be expressed, for example, in three primary colors of R (red), G (green), and B (blue). “Color of object” is a human&#39;s reaction when a light emitted from a light source is reflected on a surface of “object”, and enters into human eyes. Accordingly, “color” is a “light”, and “color of object” is a reflection characteristic on the surface of the object. This is the fundamental in the feel of material. 
   Firstly, the user in a remote site issues an instruction of drawing the annotation image in a color A, with the use of the pointing device  130  or the like on the remote terminal  100 .  FIG. 6A  is a view illustrating the annotation image determined on a remote terminal.  FIG. 6B  is a view illustrating a color component (color A) of the annotation image determined on the remote terminal. As shown in  FIG. 6B , the color components of the annotation image determined by the color A are expressed in R=0.2, G=0.5, and B=0.6. 
   If it is determined that the annotation image is drawn in the color A on the remote terminal  100  (step S 31 ), the server  50  measures the reflection characteristic of a portion on the surface of the subject onto which the annotation image is to be projected, namely, a color B of a portion in the image captured by the camcorder  20  onto which the annotation image is to be projected (step S 32 ).  FIG. 7A  is a view illustrating a portion of the subject surface onto which the annotation image is to be projected.  FIG. 7B  is a view illustrating a color components (color B) of the subject on a portion in the image onto which the annotation image is projected. As shown in  FIG. 7B , it is expressed that R=0.1, G=0.2, and B=0.3 are the color components of a portion on the subject in the image captured by the camcorder  20  onto which the annotation image is to be projected. Here, it is possible to cut out the annotation image from the captured image, since it is known at the stage of drawing which portion corresponds to the annotation image. Accordingly, it is possible to cut out the portion of the annotation image from the image captured by the camcorder  20 . Then, the server  50  measures the color B of the annotation image that has been cut out. 
   Here, according to an exemplary embodiment, measured is the reflection characteristic of a portion of the subject onto which the annotation image is to be projected, in order to reduce a calculation amount. However, the reflection characteristics of all the subjects may be calculated. It is possible to cut out the portion of the captured image onto which the annotation image is to be projected, by measuring the color B of a place where the annotation image is to be projected in the color A, since it is known at the stage of drawing which portion in the captured image corresponds to the annotation image. 
   Next, the server  50  projects the annotation image onto the subject  200  in the color A instructed by the remote terminal  100 , by means of the projector  40  (step S 33 ). However, due to the reflection characteristic on the surface of the subject  200 , it seems that the annotation image  201  is projected in a different color from the color A. Accordingly, the server  50  measures a color C of the annotation image  201  in the image captured by the camcorder  20  (step S 34 ). 
     FIG. 8A  is a view illustrating an annotation image in the image captured by the camcorder  20 .  FIG. 8B  is a view illustrating color components (color C) of the annotation image in the image captured by the camcorder  20 . As shown in  FIG. 8B , the color components (the color C) of the annotation image in the image are expressed in R=0.2, G=0.4, and B=0.5. Here, it is possible to cut out the annotation image from the captured image, since it is known at the stage of drawing which portion in the captured image corresponds to the annotation image. It is therefore possible to cut out the portion of the annotation image from the image captured by the camcorder  20 . Then, the server  50  measures the color C of the annotation image that has been cut out. 
   The server  50  determines whether the color A of the annotation image determined by the remote user on the remote terminal  100  is different from the color C of the annotation image in the image captured by the camcorder  20  (step S 35 ). The server  50  dissolves the color A and the color C into color information of the RGB color space and compares the color information. Then, if it is determined that the color A of the annotation image determined by the remote terminal  100  is different from the color C of the annotation image in the image captured by the camcorder  20  (“yes” at step S 35 ), the server  50  converts the color of the annotation image to be projected onto the subject  200 , on the basis of a comparison result between the color A of the annotation image determined by the remote terminal  100  and the reflection characteristic (of the color C) on the subject surface. That is to say, the server  50  calculates a corrected color D according to the difference between the color A and the color C. Calculation equations of the color D are shown in a following expression (1). 
   
     
       
         
           
             
               
                 
                   
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     FIG. 9  is a view illustrating color components (the color D) of the corrected annotation image. As shown in  FIG. 9 , the color component (the color D) of the corrected annotation image is expressed in R=0.5, G=0.75, and B=0.9. Then, the server  50  projects the annotation image onto the subject  200  again with the use of the corrected color D, by means of the projector  40  (step S 36 ). If the color correction process is completed (“yes” at step S 37 ), the whole process is completed. In the remote instruction system  1 , it is therefore possible to project the annotation image so as to have an actually determined color onto the surface having various reflection characteristics, since a reflection coefficient of the subject surface is measured and the color of the annotation image to be projected is adjusted in accordance with the reflection characteristic of the subject surface. 
     FIG. 10  is another process flowchart of a case where the color of the annotation image is converted and the annotation image is projected in the remote instruction system. In an example shown in  FIG. 10 , step S 43  is added to the flowchart shown in  FIG. 5 . However, other processes are same as those shown in  FIG. 5 . At step S 43 , if a mouse up is performed to complete drawing in the color A on the remote terminal  100 , the server  50  makes the projector  40  project the annotation image in the color A. Accordingly, it is possible to simplify the process subsequent to step S 44  at a timing of mouse down/up in drawing in a remote site. 
   Here, if corresponding pixels are compared and the color of the annotation image is converted so as to compare the color of the annotation image determined on the remote terminal  100  with the reflection characteristic of the subject surface, it is possible to minimize the difference of colors between adjacent pixels as much as possible by using the minimum least squares method. The server  50  may convert the color of the annotation image by calculating an average value of the pixel values composing each annotation image and comparing the colors of the whole annotation image, when the color of the annotation image is corrected by comparing the color of the annotation image determined on the remote terminal  100  with the reflection characteristic of the subject surface. 
   In the description heretofore, the example of RGB color model has been described in comparison and correction of colors, yet alternative color model such as YUV, Lab, or the like may be used. In the YUV color model, Y represents luminance, U represents chrominance of blue, and V represents chrominance of red. In the Lab color model, L represents lightness, a represents a mixture ratio of two colors, green and magenta, and b represents a mixture ratio of two colors, blue and yellow. 
   In the color correction at step S 36  as described above, if it is impossible to correct to obtain an identical color (for example, the color D becomes exceeds 1.0), it is better to combine colors (U and V in the YUV color model) on a priority basis. At this time, the luminance (Y in YUV color model) is adjusted to be a maximum as much as possible. 
   At step S 32  and S 33 , if the color exceeds a dynamic range of the camcorder  20  (for example, the color B or the color C exceeds 1.0) when the color in the image is measured, the exposure of the camcorder  20  is controlled. Here, at step S 36 , it is better to correct the color in priority, as described. On the basis of an exposure parameter e and a characteristic function f of the camcorder  20 , the camcorder  20  and the exposure parameter are set to such corrected color to calculate with the use of a following Expression (2). Here, the function f is measured in advance.
 
 R   c   =f ( R   c   ,e )  [Expression (2)]
 
   As described heretofore, according to an exemplary embodiment of the present invention, it is possible to project the annotation image having an identical color determined on the remote terminal onto the subject having various reflection characteristics, by measuring the reflection characteristics on the subject surface on the basis of the captured image, converting the color of the annotation image on the basis of such measured subject surface, and projecting the annotation image onto the subject. In addition, it is only necessary to measure the reflection characteristic of only a portion in the subject surface onto which the annotation image is to be projected. This eliminates the necessity of measuring the reflection characteristic of the whole surface of the subject, thereby enabling the annotation image having an identical color to the color determined on the remote terminal, with a small calculation amount. Furthermore, it is not necessary to add hardware such as a standard light source or the like, since only the annotation image is used for measuring the reflection characteristic on the subject surface. Also, when the color of the annotation image is corrected only on the basis of the reflection characteristic of the subject surface, it is necessary to measure a distance between the projector and the subject surface. However, in the remote instruction system  1  employed according to an exemplary embodiment of the present invention, the portion in the subject surface onto which the annotation image is to be projected is measured and is then fed back to the system, thereby eliminating the necessity of measuring the distance between the projector  40  and the subject surface. Also, according to an exemplary embodiment of the present invention, the reflection characteristic of the subject surface is measured for color correction, whenever the annotation image is projected. Even if a material of the subject is different or the position of the subject is moved frequently, it is possible to correct the color. 
   In the above-described exemplary embodiment, a description has been given of a case where the projector is used as a projection portion. However, the projection portion is not limited to the projector. For example, the image may be formed by emitting laser beams or the like at the subject. 
   In the above-described exemplary embodiment, the rotation stage has been described as an example of the relative position changing portion. However, the relative position changing portion is not limited to the rotation stage. For example, a robot or the like may be employed as the relative position changing portion. In the above-described exemplary embodiment, a description has been given of a case where the subject is moved. However, it may be configured in such a manner that the camcorder serving as an image capturing portion or the projector serving as a projection portion is moved. 
   In the above-described exemplary embodiment, a description has been given of a case where the rotation buttons R 1  and R 2  are formed on the display screen  111  to instruct the rotation of the rotation stage  70 . However, a method of instructing the rotation is not limited to the above-described rotation buttons. A keyboard or alternative method may be employed. 
   In the above-described exemplary embodiment, a description has been given of a case where the remote terminal  100  is connected to the server  50  by the network  300 . However, the connection is not limited to the network. An alternative method may be employed for connecting the remote terminal  100  and the server  50 , and the remote terminal  100  may be provided at a side of the subject  200 . 
   The remote instruction method employed in an exemplary embodiment of the present invention is realized by the remote instruction system  1 . The server  50  or the computer  120  is composed of, for example, a Central Processing Unit (CPU), Read Only Memory (ROM), Random Access Memory (RAM), and the like. 
   The foregoing description of the exemplary embodiments of the present invention has been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Obviously, many modifications and variations will be apparent to practitioners skilled in the art. The exemplary embodiments were chosen and described in order to best explain the principles of the invention and its practical applications, thereby enabling others skilled in the art to understand the invention for various embodiments and with the various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the following claims and their equivalents.