Patent Publication Number: US-2010110264-A1

Title: Image projection system

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention generally relates to systems and methods for capturing and displaying images. 
     2. Related Art 
     This section introduces aspects that may help facilitate a better understanding of the invention. Accordingly, the statements of this section are to be read in this light and are not to be understood as admissions about what is prior art or what is not prior art. 
     Various types of systems exist for capturing and displaying images. Systems are available that facilitate the transmission of an image from one location for display at another location. Systems are also available that are capable of capturing a manually-defined image. Despite these developments, there is a continuing need for improved systems for capturing and displaying images. 
     SUMMARY 
     In an example of an implementation, a system is provided, including an image projector and a video camera. The system further includes a signal processor configured to be in communication with the image projector, with the video camera, and with a video monitor. The image projector is configured for receiving and projecting a first image onto a surface of an object. The video camera is configured for capturing a second image including the first image as projected onto the object. The system is configured for transmitting the second image for display by the video monitor. 
     As another example of an implementation, a method is provided, that includes providing an image projector and a video camera. The method further includes providing a signal processor configured to be in communication with the image projector, with the video camera, and with a video monitor. In addition, the method includes causing the image projector to receive and to project a first image onto a surface of an object, and causing the video camera to capture a second image including the first image as projected onto the object, and causing the system to transmit the second image for display by the video monitor. 
     Other systems, methods, features and advantages of the invention will be or will become apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features and advantages be included within this description, be within the scope of the invention, and be protected by the accompanying claims. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       The invention can be better understood with reference to the following figures. The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. Moreover, in the figures, like reference numerals designate corresponding parts throughout the different views. 
         FIG. 1  is a schematic view showing an example of an implementation of a system. 
         FIG. 2  is a flow chart showing an example of an implementation of a method. 
     
    
    
     DETAILED DESCRIPTION 
     Collaboration among experts as well as between experts and non-experts occurs in many venues. Often, these experts and non-experts may be at separate locations at the time of their collaboration. In some cases, one person may be located at a site where a collaborative task needs to be carried out, while another person may be located off-site and perhaps quite far away from that site. An expert or non-expert may be located at either or both of the collaborative site and an off-site location, depending on the circumstances. A non-expert may be involved, as examples, as a customer for a requested task, or as a non-expert decision-maker, or in an emergency may be designated to carry out a task on-site despite lacking expertise and under the off-site direction of an expert. In many real-life situations illustrating these types of collaborations, problems may arise in attempted communication of an off-site expert&#39;s or an off-site non-expert&#39;s input to an on-site person regarding the collaborative task to be carried out. For example, that input may optimally take the form of a drawing to be utilized on-site as guidance for carrying out a task. As further examples, the off-site input may include guidance in performing a cutting operation or an operation involving ablation of a surface. Also, for example, where a task is to be carried out on a three-dimensional object, communication from an off-site location of instructions for the task, such as by a drawing, may present the added challenge of properly carrying out the drawn instructions for the task on the three-dimensional object. Feedback from the off-site person as to mapping of the drawing onto the three-dimensional object, for example, might then be helpful. 
     For example, a surgeon may be located in an operating room together with a patient on which the surgeon is tasked to perform an operation. Further, for example, the operation may have been recommended by a pathologist, cardiologist or another medical specialist, who has the proper expertise for defining the surgical procedure to be done. As an example, specific tissues of the patient, such as a tumor or a part of an organ, may be designated for removal. As another example, a bypass operation on the patient&#39;s heart may be needed. The pathologist, cardiologist or other specialist may be located across town or thousands of miles away on a different continent, such that enhancing virtual participation by the pathologist, cardiologist or other specialist in real time with the surgeon during the operation might enhance the surgeon&#39;s performance. As another example, the pathologist, cardiologist or other specialist may be located in the operating room together with the surgeon and the surgery patient, such that more precise input from the pathologist, cardiologist or other specialist regarding the operation to be performed might enhance the surgeon&#39;s performance. Once a surgeon opens an incision in the patient&#39;s body, clear demarcation of boundaries for internal incisions or other surgical maneuvers might assist the surgeon. Further, for example, an expert regarding some other manipulation to be performed on or recommended to a person may be located off-site from someone else who will manipulate or lead the person, such as an expert regarding physical therapy, medical examination, non-invasive medical procedures, dance, gymnastics, exercise, or other activities. As additional examples, an expert or other person may be located off-site from an apparatus or another object needing to be subjected to construction, repairs, analysis, or other operations, such as a jet engine, an industrial machine or system, or a computer system. In a further example, one of several people located in the same room may wish to prepare or modify a drawing in real time for viewing by another person in the room. Systems and methods are provided herein that may be utilized in preparing images to enhance collaborations among experts as well as between experts and non-experts, as illustrated by the foregoing examples. 
       FIG. 1  is a schematic view showing an example of an implementation of a system  100 . The system  100  includes an image projector  102  and a video camera  104 . The system  100  further includes a signal processor  106  configured to be in communication with the image projector  102  and with the video camera  104 . The signal processor  106  is also configured to be in communication with a video monitor  108 . The image projector  102  is configured for receiving and projecting a first image represented by a dashed arrow  110  onto a surface  112  of an object  114 . The video camera  104  is configured for capturing a second image represented by a dashed arrow  116 . The second image  116  includes a version of the first image  110  as projected onto the surface  112  of the object  114 . The system  100  is configured for transmitting the second image  116  for display by the video monitor  108 . 
     In an example, the first image  110  may include a drawing  118 . It is understood throughout this specification that the term “drawing” denotes a graphic representation, including one or more lines, of an object or idea. It is further understood throughout this specification that a “drawing” may, in addition to one or more lines, include other graphic representations. A “drawing” may be executed in black-and-white, grayscale, color, selected colors each having defined meanings, or another color scheme. A “drawing” may include solid, dashed, dotted, thin, heavy, and other types of lines. It is understood throughout this specification that the term “image” denotes a visible likeness or representation of a real or abstract thing, where examples of a real or abstract thing include an object, a person, an animal, a system, a process, and a thought. 
     The signal processor  106  may be in communication with the image projector  102  through a signal-bearing medium represented by a dashed arrow  120 , and with the video camera  104  through a signal-bearing medium represented by a dashed arrow  122 . The signal processor  106  may further be in communication with the video monitor  108  through a signal-bearing medium represented by a dashed arrow  124 . The signal-bearing media in the system  100 , such as the signal-bearing media  120 ,  122 ,  124 , may each independently include, as examples (not shown), an electrical conductor, an optical conductor, a wireless electromagnetic radiation link such as a microwave or radio link, or a combination including two or more of the foregoing. 
     In an example of operation of a system  100 , the object  114  may be a surgical patient  114  located in a hospital operating room  126 . A surgeon or other person  128  may also be located in the hospital operating room  126 , preparing to carry out an operation on the surgical patient  114 . A pathologist or other person  130  may, for example, be located in another room or other location  132  equipped with a video monitor  108 . As examples, the room  132  may be located in the same hospital or other medical facility where the operating room  126  is located, or may be across town, or may be thousands of miles away on a different continent. The image projector  102  and the video camera  104  may be in communication with the operating room  126 . The signal processor  106  may be located in the operating room  126  as shown in  FIG. 1 , or may be in communication with the operating room  126  but located elsewhere. The image projector  102  may be caused to receive and project a first image  110  onto a surface  112 , where that surface  112  in this example may be a portion of the skin or of the exposed internal tissues of the surgical patient  114 . For example, the system  100  may be configured to facilitate an input by the pathologist  130  of a drawing  118  intended by the pathologist  130  to be included in the first image  110 . The signal processor  106 , for example, may utilize the drawing  118  in generating the first image  110  as a representation of the drawing  118 . 
     Further in this example of operation, the video camera  104  is configured for capturing a second image  116  that includes a version of the first image  110  as projected onto the portion of the skin or of the exposed internal tissues  112  of the surgical patient  114 . In this example, the system  100  is configured for transmitting the second image  116  for display by the video monitor  108 . The system  100  may be further configured, for example, to facilitate an input by the pathologist  130  of additions, deletions, and other changes in the drawing  118 , based on viewing by the pathologist  130  of the second image  116  as displayed by the video monitor  108 . In this manner, for example, the pathologist  130  may effectively make changes in the version of the first image  110  as projected onto the portion of the skin or exposed internal tissues  112  of the surgical patient  114 . In this regard, for example, the system  100  may enable the pathologist  130  to observe the second image  116  and to then make changes in the drawing  118  as represented in the version of the first image  110  as projected onto the portion of the skin or exposed internal tissues  112  of the surgical patient  114 . The pathologist  130  may make these changes, for example, despite being currently located in the room  132  which may be at a distance far away from the surgeon  128  contemporaneously located in the hospital operating room  126  with the surgical patient  114 . Further, for example, these changes in the drawing  118  may be made in real-time in multiple successive iterations of changes in the drawing  118  or creation and projection of new drawings  118 , while the surgeon or other person  128  carries out an operation on the surgical patient  114 . After the surgeon  128  exposes internal tissue surfaces  112  of the surgical patient  114 , for example, a pathologist  130  may observe the second image  116  and create a new or modified drawing  118  for projection in the first image  110  onto internal tissue surfaces  112  of the surgical patient  114 . Hence, the system  100  may, for example, enable the pathologist  130  to effectively create a drawing  118  on the soft internal tissue surfaces  112  of the surgical patient  114 . 
     Furthermore, the drawing  118  may be projected in the first image  110  onto the surgical patient  114  by the system  100 , as an example, without any potential compromise of a sterile operating procedure being caused by the system  100 . The system  100  may effectively facilitate projection of stable, sterile, erasable drawings  118  in the first image  110  onto skin, soft tissue, or hard tissue of the surgical patient  114 , as examples. As another example, the pathologist  130  may effectively make changes in the version of the first image  110  as projected onto the portion of the skin or exposed internal tissues  112  of the surgical patient  114 , without having to comply with sterile operating room procedures. The pathologist  130 , for example, may be located in a non-sterile room  132  separated from the sterile operating room  126  by a large window, while revising the drawing  118 . In a further example, the pathologist  130  may be located in the operating room  126  together with the surgeon  128 . As an additional example, the person  130  may be the same person as the person  128 . As an example, a surgeon  128  may utilize the system  100  to himself create a drawing  118  for projection in the first image  110  onto a surface  112  of the surgical patient  114 . In another example, the operating room  126  may be a field location during a military or police exercise involving a surgical patient  114 , and the person  130  may be a surgeon or other medical specialist at another location  132  providing advice, instructions or other information to a person  128  such as a surgeon, to assist the person  128  in carrying out surgery or another procedure on the surgical patient  114 . 
     In an example, the system  100  may be configured for generating a digitally encoded representation of the first image  110  and a digitally encoded representation of the second image  116 . Further in that example, the system  100  may be configured for transmitting the digitally encoded representation of the first image  110  to the image projector  102  and for transmitting the digitally encoded representation of the second image  116  to the video monitor  108 . The digitally encoded representations may, as an example, include image formatting and other image control data as well as image data. As an example, the signal processor  106  may transmit the digitally encoded representation of the first image  110  through the signal-bearing medium  120  to the image projector  102 , may receive the digitally encoded representation of the second image  116  from the video camera  104  through the signal-bearing medium  122 , and may transmit the digitally encoded representation of the second image  116  through the signal-bearing medium  124  to the video monitor  108 . As an example, signal-bearing media  120 ,  122 ,  124  may be dedicated to the system  100 , or may utilize an external telecommunications network such as the Internet or a telephone network for parts or all of the transmissions. Such a network may include suitable network equipment, such as switches and routers as examples. 
     In another example, the signal processor  106  may include or be in communication with a digital video encoder  134  configured for carrying out digital encoding of the first and second images  110 ,  116 . Further, for example, the signal processor  106  may include or be in communication with a digital video decoder  135  configured for carrying out digital decoding of the first and second images  110 ,  116 . In a further example (not shown) the image projector  102  may include or be in communication with a digital video decoder (not shown) configured for decoding and facilitating projection of the first image  110  by the image projector  102 . Also for example (not shown) the video camera  104  may include or be in communication with a digital video encoder (not shown) configured for encoding the second image  116  for transmission through the system  100 . As an additional example (not shown) the video monitor  108  may include or be in communication with a digital video decoder (not shown) configured for decoding and facilitating display of the second image  116 . 
     As an example (not shown) the video monitor  108  may be configured for displaying two or all among the first and second images  110 ,  116  and the drawing  118 . In an example, the video monitor  108  may be configured to receive an input of the first image  110  from the signal processor  106  through a signal-bearing medium represented by a dashed arrow  136 . Further, as examples (not shown), the video monitor  108  may be configured to display two or all among the first and second images  110 ,  116  and the drawing  118  simultaneously or sequentially, such as side-by-side or as superimposed on each other, and where each of the first and second images  110 ,  116  and the drawing  118  may have differentiated colors, patterns, labels, or other distinguishing characteristics. 
     In an example, the surface  112  of the object  114  may be a three-dimensional surface  112 . In that case, projection of the first image  110  by the image projector  102  onto the three-dimensional surface  112  of the object  114  may result in distortions of the first image  110 . As a result, the second image  116  as captured by the video camera  104  may include a distorted version of the first image  110  superimposed on an image of the three-dimensional surface  112 . For example, the first image  110  may include a representation of a drawing  118  created by a pathologist  130  collaborating with a surgeon  128  who will carry out a surgical operation on a patient  114 . In that example, the first image  110  including a representation of the drawing  118  created by the pathologist  130  may subsequently be distorted by being projected by the image projector  102  onto the three-dimensional surface  112  of the surgical patient  114 . Further in that example, that distortion of the first image  110  may degrade the intended utility of the expertise of the pathologist  130  represented by the drawing  118  in the undistorted first image  110  intended to guide the surgeon  128  in carrying out a surgical operation on the patient  114 . Accordingly, for example, the system  100  may be configured for determining a difference between the drawing  118  and the second image  116 . Further, in that example, the system  100  may be configured for modifying the first image  110  to reduce that difference. For example, the system  100  may be configured for generating a random modification of the first image  110 , then re-determining the difference between the drawing  118  and the second image  116 , saving the first image  110  if the difference is reduced, and generating another such random modification unless the difference has become less than a selected threshold. 
     As another example, the signal processor  106  may be configured for computing a three-dimensional contour of a surface  112  of the object  114  and for correcting the first image  110  to be projected by the image projector  102 , in conformance with the contour. Display by the system  100  of the accordingly-corrected first images  110  may, for example, have the function of causing the first image  110  to appear to be fixed in position on the object  114 . 
     As an example, the system  100  may be configured to project a patterned first image  110  onto the object  114 , and to then compute a difference between the patterned first image  110  and a resulting second image  116 . In an example, the image projector  102  may be configured for projecting such a patterned first image  110 , such as a rectangular grid (not shown) onto the object  114 . The system  100  may, for example, further be configured to utilize that difference for computing a three-dimensional contour of a surface  112  of the object  114  and for correcting the first image  110  to be projected by the image projector  102 , in conformance with the contour. For example, the object  114  may be a surgical patient  114 , and the signal processor  106  may be configured for computing a three-dimensional contour of a portion of the skin or exposed internal tissues  112  of the surgical patient  114 . Further, the signal processor  106  may be configured for then computing corrections to the first image  110  in conformance with the contour. For example, the video camera  104  may be configured for capturing an image of the surface  112  of the object  114 , and the signal processor  106  may be configured to utilize that image of the surface  112  for then computing a three-dimensional contour of the surface  112  of the object  114 . Further, for example, the signal processor  106  may be configured to then utilize that three-dimensional contour for correcting the first image  110  in conformance with the contour. The system  100  may be configured, as another example, to utilize the first image  110  and the image of the surface  112  of the object  114 , in computing a three-dimensional contour of the object  114  and for correcting the first image  110  in conformance with the contour. Further, for example, the system  100  may be configured to also determine a difference between the drawing  118  and the second image  116 , and to then reduce that difference by modifying the first image  110 . 
     As an alternative to configuring the system  100  to project a patterned first image  110  onto the object  114  for then computing a difference between the patterned first image  110  and a resulting second image  116 , that difference to be further utilized as discussed above, the system  100  may for example instead be configured to include a second video camera (not shown) in addition to the video camera  104  for computing such a difference. In that example, the two video cameras may be positioned at two different angles relative to the object  114  for each capturing a second image  116 . In that example, the second image  116  captured by the video camera  104  may be compared with the second image (not shown) captured by the second video camera (not shown), and differences between the second images  116  may be analyzed for computing a three-dimensional contour of the surface  112  of the object  114 . 
     As an example, the system  100  may include a video camera  138  configured for being carried or worn by a surgeon or other person  128 . Further, for example, the system  100  may include an image projector  140  configured for being carried or worn by the person  128 . As examples, the video camera  138  and the image projector  140  may be incorporated into or configured for attachment to eyeglasses or another wearable head-piece (not shown). The signal processor  106  may, for example, be configured to be in communication with the video camera  138  and with the image projector  140 . The image projector  140  may be configured, as an example, for projecting a first image represented by a dashed arrow  142  onto the surface  112  of the object  114 . The video camera  138  may be configured, in another example, for capturing a second image represented by a dashed arrow  144 . In examples, the image projector  140  may be in communication with the signal processor  106  through a signal-bearing medium represented by a dashed arrow  146 , and the video camera  138  may be in communication with the signal processor  106  through a signal-bearing medium represented by a dashed arrow  148 . As an example, the system  100  may include both of the image projectors  102 ,  140 ; and may include both of the video cameras  104 ,  138 . In that example, the system  100  may enable a person  128  located in the same room  126  as the object  114 , or a person  130  located elsewhere, or both of them, to select which of the image projectors  102 ,  140  and which of the video cameras  104 ,  138  are operational at a given time. Further, for example, both of the video cameras  104 ,  138  may together be operational, and two different versions of the second image  116 ,  144  may be simultaneously or sequentially displayed by the video monitor  108 . As another example, both of the image projectors  102 ,  140  may together be operational, and two different first images  110 ,  142  including representations of two different drawings  118  may be simultaneously or sequentially projected onto the object  114 . Further, for example, a system  100  may be configured to include either the image projector  102  or the image projector  140 , and the system  100  may be configured for utilization of the video cameras  104 ,  138  respectively by the persons  130 ,  128 . A system  100  may, for example, be configured to include a selected one of the image projectors  102 ,  140 . Further, for example, a system  100  may be configured to include a selected one of the video cameras  104 ,  138 . 
     In further examples, the video cameras  104 ,  138  may be configured to facilitate zoom functionality to adjust the image field size for receiving a second image  116 ,  144  within a range of close-up, mid-field and distant images. In addition, the image projectors  102 ,  140  may be configured to facilitate zoom functionality to adjust the image field for projecting a first image  110 ,  142  within a range of close-up, mid-field and distant images. The zoom functionality of the image projectors  102 ,  140  and of the video cameras  104 ,  138  may, as examples, additionally or alternatively be digitally generated by the signal processor  106 . Further, for examples, the image projectors  102 ,  140  and the video cameras  104 ,  138  may be configured for panning over surfaces  112  of the object  114 . Additionally, the system  100  may be configured for synchronizing together the image projector  102  and the video camera  104  in panning and zooming operations, and likewise for synchronizing together the image projector  140  and the video camera  138  in panning and zooming operations. As another example, panning of the image projector  140  and the video camera  138  may depend upon movement of the person  128  who may be wearing or carrying them. 
     The system  100  may, for example, be configured for generating the first image  110 ,  142  utilizing a manually-created arbitrary drawing  118 . For example, a pathologist or other person  130  may manually create an arbitrary drawing  118 . An arbitrary drawing  118  may, for example, be tailored by the person  130  to external or internal tissue surfaces  112  of a particular patient  114  and to the particular surgical operation to be performed by the surgeon  128  on that patient  114 . The system  100  may be configured, for example, to enable the person  130  to input the drawing  118  to the signal processor  106  so that the first image  110 ,  142  may be generated and provided to a surgeon or other person  128  for use in mapping a surgical operation onto a portion of the skin or exposed internal tissues  112  of a surgical patient  114 . As an example, the system  100  may include an input device  150  configured for capturing the manually created drawing  118 . For example, the input device may be integrated into a video monitor  151 . The input device  150  may be configured to communicate with the signal processor  106  through a signal-bearing medium represented by a dashed arrow  152 , and the signal processor  106  may be configured for utilizing the manually created drawing  118  to generate the first image  110 ,  142 . The input device  150  may further be configured, for example, to display an image of the object  114  over which the pathologist or other person  130  may manually create the drawing  118  for input to the signal processor  106 . For example, the input device  150  may include an image display panel  154  and may be configured for detecting, capturing and displaying the drawing  118  as manually created on the image display panel  154  by a person  130 . Further, for example, the input device  150  may be aligned to function in cooperation with the image display panel  154 . As examples, the input device  150  may detect stylus pressure on the image display panel  154 , or may detect changes in ambient light or in pressure caused by movement of a stylus or other object such as a fingertip over the image display panel  154 . 
     In an example, the video monitor  108  may be separate and distinct from the system  100 . Further, for example, the system  100  may be configured to communicate with the video monitor  108  through signal-bearing media  124 ,  136 . In another example, the video monitor  108  may be an integral part of the system  100 . As a further example, the video monitor  108  may include an input device  156  that is integral with the video monitor  108 . In that case, the input device  150  may for example be omitted. In an example, the video monitor  108  may be configured for displaying an image such as the second image  116  on an image display panel  158 . Further, for example, the input device  156  may be aligned to function in cooperation with the image display panel  158  of the video monitor  108 . The input device  156  may be configured, for example, for receiving manual inputs of additions, deletions, and other changes to be made in the second image  116 ,  144 . The input device  156  may, for example, be configured for detecting and capturing changes to be made in the second image  116 ,  144  as manually indicated on the image display panel  158  by a person  130 . As examples, the input device  156  may detect stylus pressure on the image display panel  158 , or may detect changes in ambient light or in pressure caused by movement of a stylus or other object such as a fingertip over the image display panel  158 . The input device  156  may be configured to communicate with the signal processor  106  through a signal-bearing medium represented by a dashed arrow  160 , and the signal processor  106  may be configured for utilizing changes detected in the second image  116 ,  144  that is displayed on the image display panel  158 , to generate the first image  110 ,  142 . 
     In another example, the video monitor  108  may be configured to display the first image  110 ,  142 , and the input device  156  may be configured, for example, for receiving manual inputs of additions, deletions, and other changes to be made in the first image  110 ,  142 . As a further example, the video monitor  108  may be configured to display the drawing  118 , and the input device  156  may be configured, for example, for receiving manual inputs of additions, deletions, and other changes to be made in the drawing  118 . In another example, the system  100  may be configured for selecting a pre-determined drawing for utilization as a starting point in manual generation of the drawing  118 . Further according to that example, the input device  156  may be configured to enable a person  130  to manually make additions, deletions, and other changes in the pre-determined drawing to generate the drawing  118 . Also, for example, the system  100  may be configured for access to a database (not shown) for storage and retrieval of such pre-determined drawings. In further examples, the video monitor  108  may be configured for simultaneously, sequentially, or selectively displaying two or more images from among the first image  110 ,  142 , the second image  116 ,  144 , the drawing  118 , and an image of the object  114 . 
     The input devices  150 ,  156  may, as examples, be configured for receiving manual drawing inputs including additions, erasures, and other changes to be made to the first image  110 ,  142 , second image  116 ,  144 , or drawing  118  as may be displayed on image display panels  154 ,  158  of the input devices  150 ,  156 . Such changes may include, as further examples, copying, pasting, stretching, inverting, and otherwise manipulating drawings and parts of drawings included in the first image  110 ,  142 , second image  116 ,  144 , or drawing  118 . For example, the input devices  150 ,  156  may be configured for communication with the signal processor  106 , wherein the signal processor  106  may have access to software suitable for causing the signal processor  106  to compute and to communicate to the input devices  150 ,  156 , revised versions of the first image  110 ,  142 , second image  116 ,  144 , or drawing  118  reflecting the manual drawing inputs. As further examples, the input devices  150 ,  156  may themselves be configured for access to software suitable for computing and communicating to the signal processor  106 , revised versions of the first image  110 ,  142 , second image  116 ,  144 , or drawing  118  reflecting the manual drawing inputs. Further, for example, the software may manage operation of the system  100  to select between utilization of the image projector  102  or the image projector  140 , and to select between utilization of the video camera  104  or the video camera  138 . 
     In another example, the image projector  102  may include a projector position sensor  162  capable of generating projector position information. Further, for example, the video camera  104  may include a camera position sensor  164  capable of generating camera position information. Where the system  100  includes both the projector position sensor  162  and the camera position sensor  164 , the system  100  may, as an example, be configured for utilizing the position information in synchronizing together, relative to the object  114 , a projector orientation and a camera orientation, regardless of how the image projector  102  or the video camera  104  are moved. Further, for example, the system  100  may be configured for utilizing the position information in generating the first image  110 . 
     In an example, the projector position information and camera position information may be utilized by the system  100  in causing the first image  110  to appear frozen in a fixed position on a selected portion of the skin or exposed internal tissues  112  of a surgical patient  114 . As another example, the position sensors  162 ,  164  may be omitted, but the system  100  may still have the effect of causing the first image  110  to appear so fixed on the object  114 . In that example, the system  100  may be configured to calculate rapid, real-time updates of the first image  110  in response to detected changes in the second image  116 . These updates may, for example, cause the first image  110  to appear to be fixed and immovable on the surface  112  of the object  114  despite movement of the object  114 , or of internal parts of the object  114 , or of the image projector  102  itself. The accuracy and speed of the updates may, for example, be increased by including position sensors  162 ,  164  in the system  100 . 
     The image projector  102  may include, for example, a mounting device (not shown) configured for moving the image projector  102  through a range of motion suitable for operation of the system  100 . As an example, such a mounting device for the image projector  102  may include (not shown) a counter-balanced suspension arm. The video camera  104  may, for example, analogously include (not shown) a mounting device, which may likewise include a counter-balanced suspension arm. As an example, the image projector  102  and the video camera  104  may both be located on the same mounting device (not shown), such as a counter-balanced suspension arm. In further examples (not shown), the projector position sensor  162  may include a magnetic or electrically-resistive sensor, or an accelerometer, or a gyroscope. For example, magnetic or electrically-resistive sensors may be located at one or more joints of a counter-balanced suspension arm on which the image projector  102  may be mounted. Further, as examples, the camera position sensor  164  may include a magnetic or electrically-resistive sensor, or an accelerometer, or a gyroscope. For example, magnetic or electrically-resistive sensors may be located at one or more joints of a counter-balanced suspension arm on which the video camera  104  may be mounted. 
     In another example, the image projector  140  may likewise include a projector position sensor (not shown) capable of generating projector position information. Further, for example, the video camera  138  may likewise include a camera position sensor (not shown) capable of generating camera position information. 
     The system  100  may be configured, for example, for utilizing changes in the projector position information or the camera position information or both types of position information, in computing a three-dimensional contour of the object  114  and for correcting the first image  110  in conformance with the contour. For example, the system  100  may be configured for access to suitable software for utilizing second images  116  of the object  114  received from the video camera  104 ,  138 , and such position information, for computing such contours and corrected first images  110 . Display by the system  100  of the accordingly-corrected first images  110  may, for example, have the function of causing the first image  110  to appear to be fixed in position on the object  114 . 
     In another example, the image projector  102 ,  140  may be configured for projecting a first image  110 ,  142  onto a surface  112  of an object  114  in a form of laser light. As examples, the laser light may include laser light having suitable power and focal concentration for cutting or ablating the surface  112  of the object  114 . For example, the system  100  so configured may be utilized for defining, through the drawing  118 , a cutting or ablating operation to be carried out on a surface  112  of the skin or internal tissues of a patient  114 . As further examples, the system  100  so configured may be utilized for defining, through the drawing  118 , a cutting or ablating operation to be carried out on another object  114 , such as a work piece to be cut or ablated. As examples, such a work piece may include wood, metal, textiles, or other materials to be cut, or a block of material to be sculpted into an arbitrary shape. 
     The image projectors  102 ,  140  of the system  100  may be implemented by any projectors suitable for the projection of light as the first image  110 ,  142  onto an object  114 . For example, the image projectors  102 ,  140  may be liquid crystal display (“LCD”) projectors, or may be other types of projectors such as, for example, have been utilized in projection television applications or for projecting an image such as a slide presentation onto a reflective screen. In examples, either or both of the image projectors  102 ,  140  may or may not be miniaturized. 
     The video cameras  104 ,  138  of the system  100  may be implemented by any cameras suitable for receiving and transmitting the second images  116 ,  144 . The transmission of the second images  116 ,  144  may be, as examples, in electronic or optical form. Further, for example, the second images  116 ,  144  may be transmitted in analog or digital format. In examples, either or both of the video cameras  104 ,  138  may or may not be miniaturized. 
     The signal processor  106  may be implemented by hardware, or by a combination of hardware together with either software or firmware or both software and firmware. As examples, the hardware may include one or more input modules and one or more processing modules. Examples of a processing module include a microprocessor, a general purpose processor, a digital signal processor, a logic- or decision-processing unit, a field-programmable gate array (FPGA), and an application-specific integrated circuit. If the signal processor  106  is implemented in part by software, the software may for example reside in software memory to which the signal processor  106  has access or which is integral to the signal processor  106  and which is utilized to execute the software. The software may include an ordered listing of executable instructions for implementing the signal processor  106  either in digital form such as digital circuitry or source code, or analog circuitry or an analog source such an analog electrical, sound or video signal. The software may implement algorithms configured for causing the system  100  to perform various functions such as, for example, detecting manual generation of the drawings  118 , generating the first images  110 ,  142  from the drawings  118 , correcting the first images  110 ,  142  for distortions due to projection of the first images  110 ,  142  onto a three-dimensional object  114 , otherwise correcting and revising the first images  110 ,  142  including response to additions, deletions, and other changes input to the system  100  by the person  130 , controlling the image projectors  102 ,  140  and the video cameras  104 ,  138 , and distributing the first and second images  110 ,  116 ,  142 ,  144  within the system  100 . 
     The video monitor  108  may be implemented by a device including an image display panel  154 ,  158  suitable for receiving and displaying the second images  116 ,  144 , such as a LCD planar array, a plasma display, a cathode ray tube, or another device serving such an image display function. The input device  150 ,  156  may be implemented by a device including an image display panel  154 ,  158  also suitable for detecting the manual generation of the drawings  118 . As an example, the input device  150 ,  156  may include a sensor array configured for detecting and mapping array coordinates of pressure applied onto the sensors, such as by a stylus or fingertip. Further, for example, the input device  150 ,  156  may include a sensor array configured for detecting and mapping coordinates in the array, of changes in ambient light impinging on the sensor array resulting from movement of an object such as a stylus or fingertip over sensors in the array. In further examples, the input devices  150 ,  156  may include a keyboard, mouse, or light pen (not shown) for generating the drawings  118 . Where a system  100  includes a video monitor  108  having an input device  156 , such a sensor array may for example be integral with the video monitor  108 . 
     A system  100  may be configured with a single image projector  102 , a single video camera  104 , and a single signal processor  106 ; or may include a plurality of one or more of any or all of the same components of the system  100 . Likewise, an example of a system  100  may include one or a plurality of video monitors  108 , one or a plurality of input devices  150 ,  156 , one or a plurality of digital video encoders  134 , or one or a plurality of digital video decoders  135 . It is understood that a system  100  may further include either one or a plurality of any of the other system components discussed herein. It is understood that all references herein to a given component of a system  100  may be applied in an analogous manner to any components of the same type or having the same function in the system  100 . It is understood that all references herein to the persons  128 ,  130  include utilization of the system  100  by either one or a plurality of persons  128  and by either one or a plurality of persons  130 . The persons  130  may be at one or a plurality of locations  132 . 
       FIG. 2  is a flow chart showing an example of an implementation of a method  200 . The method starts at step  205 . Step  210  includes providing an image projector  102 ,  140  and a video camera  104 ,  138 ; and providing a signal processor  106  configured to be in communication with the image projector  102 ,  140 , with the video camera  104 ,  138 , and with a video monitor  108 . Step  215  includes causing the image projector  102 ,  140  to receive and to project a first image  110 ,  142  onto a surface  112  of an object  114 ; causing the video camera  104 ,  138  to capture a second image  116 ,  144  including the first image  110 ,  142  as projected onto the object  114 ; and causing the system  100  to transmit the second image  116 ,  144  for display by the video monitor  108 . The method may end at step  220 . 
     In an example, step  215  may include generating a digitally encoded representation of the first image  110 ,  142  and a digitally encoded representation of the second image  116 ,  144 , transmitting the digitally encoded representation of the first image  110 ,  142  to the image projector  102 ,  140 , and transmitting the digitally encoded representation of the second image  116 ,  144  to the video monitor  108 . As another example, step  215  may include displaying both of the first and second images  110 ,  116 ,  142 ,  144  on the video monitor  108 . 
     The method may as another example include, at step  215 , determining a difference between the drawing  118  and the second image  116 ,  144  and then modifying the first image  110 ,  142  to reduce the difference. For example, step  215  may include generating a random modification of the first image  110 ,  142 , then re-determining the difference between the drawing  118  and the second image  116 ,  144 , saving the first image  110 ,  142  if the difference is reduced, and generating another such random modification unless the difference has become less than a selected threshold. 
     As another example, the method may include, at step  215 , action by the person  130  to visually determine a difference between the second image  116 ,  144  and the intended drawing (not shown) envisioned by the person  130  as represented in the drawing  118 . Next in that example, the person  130  may modify the drawing  118  based on that person&#39;s envisioned drawing (not shown) while observing the resulting changes in the second image  116 ,  144 . In that example, the person  130  may attempt to modify the drawing  118  so that the second image  116 ,  144  may appear the same as that person&#39;s envisioned drawing (not shown). 
     Further, for example, step  215  may include causing the signal processor  106  to compute a three-dimensional contour of the object  114  and to correct the first image  110 ,  142  in conformance with the contour. Display of the accordingly-corrected first images  110 ,  142  may, for example, have the function of causing the first image  110 ,  142  to appear to be fixed in position on the object  114 . 
     Step  215  may, for example, include causing the video camera  138  or the image projector  140  or both, to be carried or worn by a person  128 . In another example, step  215  may include utilizing the system  100  wherein the object  114  includes a surgical patient  114 . 
     Providing the image projector  102 ,  140  at step  210  may, for example, include providing a projector position sensor  162  capable of generating projector position information. Providing the video camera  104 ,  138  at step  210  may, for example, include providing a camera position sensor  164  capable of generating camera position information. Step  215  may, as an example, include utilizing the projector position information and the camera position information in synchronizing together, relative to the object  114 , an orientation of the image projector  102 ,  140  and an orientation of the video camera  104 ,  138 . Further, for example, step  215  may include utilizing the projector position information and camera position information to assist in causing the first image  110 ,  142  to appear frozen in a fixed position on a selected portion of the skin or exposed internal tissues  112  of a surgical patient  114 . As another example, step  215  may omit utilization of projector and camera position information, but may still have the effect of causing the first image  110  to appear fixed on the object  114 . In that example, rapid, real-time updates of the first image  110  may be calculated in response to detected changes in the second image  116 . These updates may, for example, cause the first image  110  to appear to be fixed and immovable on the surface  112  of the object  114  despite movement of the object  114 , or of internal parts of the object  114 , or of the image projector  102  itself. The accuracy and speed of the updates may, for example, be increased by utilizing projector and camera position information in step  215 . 
     Further, for example, step  215  may include utilizing changes in the projector position information and in the camera position information in computing a three-dimensional contour of the object  114  and for correcting the first image  110 ,  142  in conformance with the contour. Additionally, step  215  may include utilizing such a three-dimensional contour of the object  114  together with the position information, in both causing the first image  110 ,  142  to remain in a fixed position on the object  114  and in computing a three-dimensional contour of the object  114  for correcting the first image  110 ,  142  in conformance with the contour. 
     In an additional example, step  215  may include generating the first image  110 ,  142  utilizing a manually-created drawing  118 . Further, for example, step  210  may include providing an input device  150 ,  156  configured for capturing a representation of the manually created drawing  118 , and including an image display panel  154 ,  158 . Step  215  may, for example, include causing the signal processor  106  to utilize the representation of the manually created drawing  118  to generate the first image  110 ,  142 . Step  215  may, as an example, include causing the image display panel  154 ,  158  to display the drawing  118 , the first image  110 ,  142 , the second image  116 ,  144 , or an image of the object  114 , or a combination including two or more of the foregoing. In another example, providing the video monitor  108  in step  210  may include providing a video monitor  108  that includes an image display panel  158  configured for displaying the first image  110 ,  142 , the second image  116 ,  144 , or an image of the object  114 , or a combination including two or more of the foregoing; and providing the input device  156  and the video monitor  108  may include providing the input device  156  integrally with the video monitor  108  and aligned to function in cooperation with the image display panel  158 . Further, for example, step  215  may include causing the first image  110 ,  142  to be modified in response to changes in the drawing  118 ; as captured by the input device  150 ,  156 . 
     The system  100  may, for example, be utilized to facilitate projection of a first image  110 ,  142  onto an object  114  in the presence of a person  128 , wherein the first image  110 ,  142  may be modified by a person  130 . The person  130  may be present with the person  128 , or may be located elsewhere, or may be one and the same person. The person  128  may, as examples, be an expert in performing a task with regard to the object  114 , or may be a layman. The person  130  may, as examples, be an expert in providing advice or instructions with regard to the task to be performed, or may be a layman. As examples, the person  128  may be a surgeon, another type of medical professional, a dance instructor, a physical therapist, a mechanic, a computer technician, a worker tasked with constructing, repairing or operating an apparatus  114 , or a layman with no particular expertise regarding but present together with the object  114  for performing the task. In further examples, the person  130  may be a surgeon, another type of medical professional, a dance instructor, a physical therapist, a mechanic, a computer technician, a worker tasked with constructing, repairing or operating an apparatus  114 , or a layman with no particular expertise regarding the task to be performed regarding the object  114  but otherwise having input into performance of the task by the person  128 . For example, the person  128  may be a surgeon, and the person  130  may be a pathologist or other medical professional called upon to provide guidance to the surgeon  128  in performing a surgical procedure on a patient  114 . The method  200  may be utilized in connection with operating a suitable system  100  including an image projector  102 ,  140 , a video camera  104 ,  138 , and a signal processor  106  configured to be in communication with the image projector  102 ,  140 , with the video camera  104 ,  138 , and with a video monitor  108 , of which the systems  100  disclosed are only examples. The method  200  may include additional steps and modifications of the indicated steps. 
     It is understood that the various examples of the system  100  illustrate analogous examples of variations of the method  200 , and the entire discussion of the system  100  is accordingly deemed incorporated into the discussion of the method  200 . Likewise, it is understood that the various examples of the method  200  illustrate analogous examples of variations of the system  100 , and the entire discussion of the method  200  is accordingly deemed incorporated into the discussion of the system  100 . 
     Moreover, it will be understood that the foregoing description of numerous examples has been presented for purposes of illustration and description. This description is not exhaustive and does not limit the claimed invention to the precise forms disclosed. Modifications and variations are possible in light of the above description or may be acquired from practicing the invention. The claims and their equivalents define the scope of the invention.