Abstract:
A system and method for tool enhancements are provided which allow users to utilize video tools in a controlled manner. The video tools balance a minimal amount of cursor positioning and “mouse clicks” against a level of video tool “customization” control desired by a user when applying the video tools. Tool construction methods using multiple mouse clicks are provided as an alternative to using drag-and-draw and one-click tools. Multi-click-plus tools give more specific information and provide a precise way to rapidly create customized tools.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of U.S. Provisional Application No. 60/648,956, filed Jan. 31, 2005, under the provisions of 35 U.S.C. § 119. 
    
    
     FIELD OF THE INVENTION 
     The invention relates generally to machine vision inspection systems, and more particularly to video metrology tools usable to define inspection operations for such systems. 
     BACKGROUND OF THE INVENTION 
     Precision machine vision inspection systems (or “vision systems” for short) can be utilized to obtain precise dimensional measurements of inspected objects and to inspect various other object characteristics. Such systems may include a computer, a camera and optical system, and a precision stage that is movable in multiple directions so as to allow the camera to scan the features of a workpiece that is being inspected. One exemplary prior art system that is commercially available is the QUICK VISION® series of PC-based vision systems and QVPAK® software available from Mitutoyo America Corporation (MAC), located in Aurora, Ill. The features and operation of the QUICK VISION® series of vision systems and the QVPAK® software are generally described, for example, in the  QVPAK  3 D CNC Vision Measuring Machine User&#39;s Guide , published January 2003, and the  QVPAK  3 D CNC Vision Measuring Machine Operation Guide , published September 1996, each of which is hereby incorporated by reference in their entirety. This product, as exemplified by the QV-302 Pro model, for example, is able to use a microscope-type optical system to provide images of a workpiece at various magnifications, and move the stage as necessary to traverse the workpiece surface beyond the limits of any single video image. A single video image typically encompasses only a portion of the workpiece being observed or inspected, given the desired magnification, measurement resolution, and physical size limitations of such systems. 
     Machine vision inspection systems generally utilize automated video inspection. U.S. Pat. No. 6,542,180 teaches various aspects of such automated video inspection and is incorporated herein by reference in its entirety. As taught in the &#39;180 patent, automated video inspection metrology instruments generally have a programming capability that allows an automatic inspection event sequence to be defined by the user for each particular workpiece configuration. This can be implemented by text-based programming, for example, or through a recording mode which progressively “learns” the inspection event sequence by storing a sequence of machine control instructions corresponding to a sequence of inspection operations performed by a user, or through a combination of both methods. Such a recording mode is often referred to as “learn mode” or “training mode.” Once the inspection event sequence is defined in “learn mode,” such a sequence can then be used to automatically acquire (and additionally analyze or inspect) images of a workpiece during “run mode.” 
     The machine control instructions including the specific inspection event sequence (i.e., how to acquire each image and how to analyze/inspect each acquired image) are generally stored as a “part program” or “workpiece program” that is specific to the particular workpiece configuration. For example, a part program defines how to acquire each image, such as how to position the camera relative to the workpiece, at what lighting level, at what magnification level, etc. Further, the part program defines how to analyze/inspect an acquired image, for example, by using one or more video tools such as edge/boundary detection video tools. 
     Video tools may be used manually to accomplish manual inspection and/or machine control operations. Also, their set-up parameters and operation can also be recorded during learn mode, in order to create automatic inspection programs, or “part programs”. Such tools may include, for example, edge/boundary detection tools, shape or pattern matching tools, dimension measuring tools, coordinate establishing tools, and the like. For example, such tools are routinely used in a variety of commercially available machine vision inspection systems, such as the QUICK VISION® series of vision systems and the associated QVPAK® software, discussed above. 
     Video edge/boundary detection tools available in QVPAK® software include, for example, Point tool, Box tool, Circle tool, and Arc tool (see QVPAK 3D CNC Vision Measuring Machine User&#39;s Guide, incorporated by reference above). Briefly, a Point tool generates (locates) a data point at the intersection of a single scan line on an image. A Box tool generates a series of parallel scan lines, each of which returns a data point where an edge feature is found. A Circle tool generates a series of radial scan lines, over 360 centered about an origin, each of which returns a point where an edge feature is found. An Arc tool generates a series of radial scan lines centered about an origin, each of which returns a point where an edge feature is found (useful for returning data points from a rounded corner, for example). Each of these tools may be used to automatically detect a particular edge/boundary feature in an image. 
     Proper operation of a video tool depends on correct settings of various machine, image acquisition, and video tool parameters that affect the image quality and the operation of the video tool. For example, for an edge/boundary detection video tool to locate a target edge/boundary in an image, the machine and image acquisition parameters must set a correct level of lighting/brightness, proper focusing, proper magnification, etc. Video tool parameters, for example for an edge-detection video tool, may include a region of interest of (i.e., the region within a video image that the video tool searches), an edge selector, a scan direction, and other parameters are that set to properly control the operations of the video tool to locate the edge/boundary feature that is desired be detected. 
     The currently available features and graphical user interface (GUI) controls for video tools, and particularly dimensional metrology video tools, are limited. Some existing video tools require relatively few “setup” actions by the user, but have the disadvantage that many of the resulting video tool parameters are set to default values that may be inappropriate in many situations. Other existing video tools allow the video tool parameters to be extensively adjusted or customized by the user, but have the disadvantage that they require several independent setup actions by the user. Video tools that overcome these and other disadvantages would be desirable. 
     SUMMARY OF THE INVENTION 
     Currently, the users of precision machine vision inspection systems may spend a majority of their part-programming time setting up video tools and adjusting their parameters. Thus, even small improvements in their ease-of-use in comparison to their parameter customization capability, their GUI features, and other ergonomic factors, may be highly valued. The present invention is directed to novel and efficient instances of the video tools outlined above, as well as other video tools. A system and method for tool enhancements are provided which allow users to utilize video tools in a controlled manner. The video tools balance a minimal amount of cursor positioning and “mouse clicks” against a level of video tool “customization” control desired by a user when applying the video tools. Tool construction methods using multiple mouse clicks are provided as an alternative to using known drag-and-draw and one-click tool methods. The multi-click-plus and/or multi-click tools disclosed herein may convey more specific tool parameter information than known similar tools and provide a precise way to create tools. The multi-click-plus and/or multi-click tools disclosed herein may allow a user to determine a plurality of tool parameters with a single user action. These new video tool methods give users a high level of control over tool parameter creation with a simple and/or minimum set of user actions. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same become better understood by reference to the following detailed description when taken in conjunction with the accompanying drawings, wherein: 
         FIG. 1  is a diagram showing various typical components of a general purpose machine vision inspection system; 
         FIG. 2  is a diagram of a control system portion and a vision components portion of a machine vision inspection system; 
         FIGS. 3A-3C  are diagrams illustrating the operation of an exemplary box tool on an imperfect edge feature; 
         FIG. 4  is a diagram illustrating the operation of the exemplary box tool of  FIG. 3 , on a notched edge feature; 
         FIGS. 5A-5D  are diagrams illustrating the operation of an exemplary circle tool on a circular feature; 
         FIG. 6  is a diagram illustrating the operation of the exemplary circle tool of  FIG. 5 , on a notched circular feature; 
         FIGS. 7A-7D  are diagrams illustrating the operation of an exemplary arc tool on an arc feature; 
         FIGS. 8A-8C  are diagrams illustrating the operation of an exemplary edge auto focus tool on an edge feature; 
         FIGS. 9A-9C  are diagrams illustrating the operation of an exemplary dual area contrast tool on an edge feature; 
         FIGS. 10A and 10B  are flow diagrams illustrative of one embodiment of a routine for operation of a multi-click-plus video tool; 
         FIG. 11  is a diagram illustrating a toolbar from which various video tools and video tools modes may be selected; and 
         FIGS. 12A and 12B  are diagrams of a chart that illustrates operations for setting the parameters of various multi-click-plus and multi-click video tools. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       FIG. 1  is a block diagram of one exemplary machine vision inspection system  10  usable in accordance with the present invention. The machine vision inspection system  10  includes a vision measuring machine  12  that is operably connected to exchange data and control signals with a controlling computer system  14 . The controlling computer system  14  is further operably connected to exchange data and control signals with a monitor or display  16 , a printer  18 , a joystick  22 , a keyboard  24 , and a mouse  26 . The monitor or display  16  may display a user interface suitable for controlling and/or programming the operations of the machine vision inspection system  10 . 
     The vision measuring machine  12  includes a moveable workpiece stage  32  and an optical imaging system  34  which may include a zoom lens or interchangeable lenses. The zoom lens or interchangeable lenses generally provide various magnifications for the images provided by the optical imaging system  34 . The machine vision inspection system  10  is generally comparable to the QUICK VISION® series of vision systems and the QVPAK® software discussed above, and similar state-of-the-art commercially available precision machine vision inspection systems. The machine vision inspection system  10  is also described in copending and commonly assigned U.S. patent application Ser. No. 10/978,227, which is hereby incorporated by reference in its entirety. Various aspects of vision measuring machines and control systems are also described in more detail in copending and commonly assigned U.S. patent application Ser. Nos. 10/808,948, filed Mar. 25, 2004, and 10/632,823, filed Aug. 4, 2003, which are also hereby incorporated by reference in their entirety. 
       FIG. 2  is a diagram of a control system portion  120  and a vision components portion  200  of a machine vision inspection system  100  in accordance with the present invention. As will be described in more detail below, the control system portion  120  is utilized to control the vision components portion  200 . The vision components portion  200  includes an optical assembly portion  205 , light sources  220 ,  230  and  240 , and a workpiece stage  210  having a central transparent portion  212 . The workpiece stage  210  is controllably movable along X and Y axes that lie in a plane that is generally parallel to the surface of the stage where a workpiece  20  may be positioned. The optical assembly portion  205  includes a camera system  260 , an interchangeable objective lens  250 , and may include a turret lens assembly  280 , and the coaxial light source  230 . Alternatively to the turret lens assembly, a fixed or manually interchangeable magnification-altering lens, or a zoom lens configuration, or the like, may be included. The optical assembly portion  205  is controllably movable along a Z axis that is generally orthogonal to the X and Y axes, by using a controllable motor  294 , as described further below. 
     A workpiece  20  that is to be imaged using the machine vision inspection system  100  is placed on the workpiece stage  210 . One or more of the light sources  220 ,  230 , and  240  emits source light  222 ,  232 , or  242 , respectively, that is usable to illuminate the workpiece  20 . Light emitted by the light sources  220 ,  230 , and/or  240  illuminates the workpiece  20  and is reflected or transmitted as workpiece light  255 , which passes through the interchangeable objective lens  250  and the turret lens assembly  280  and is gathered by the camera system  260 . The image of the workpiece  20 , captured by the camera system  260 , is output on a signal line  262  to the control system portion  120 . 
     The light sources  220 ,  230 , and  240  that are used to illuminate the workpiece  20  can include a stage light  220 , a coaxial light  230 , and a surface light  240 , such as a ring light or a programmable ring light, all connected to the control system portion  120  through signal lines or busses  221 ,  231 , and  241 , respectively. As a primary optical assembly of the machine vision inspection system  100 , the optical assembly portion  205  may include, in addition to the previously discussed components, other lenses, and other optical elements such as apertures, beam-splitters and the like, such as may be needed for providing coaxial illumination, or other desirable machine vision inspection system features. When it is included as a secondary optical assembly of the machine vision inspection system  100 , the turret lens assembly  280  includes at least a first turret lens position and lens  286  and a second turret lens position and lens  288 . The control system portion  120  rotates the turret lens assembly  280  along axis  284 , between at least the first and second turret lens positions, through a signal line or bus  281 . 
     The distance between the workpiece stage  210  and the optical assembly portion  205  can be adjusted to change the focus of the image of the workpiece  20  captured by the camera system  260 . In particular, in various exemplary embodiments, the optical assembly portion  205  is movable in the vertical Z axis direction relative to the workpiece stage  210  using a controllable motor  294  that drives an actuator, a connecting cable, or the like, to move the optical assembly portion  205  along the Z axis. The term Z axis, as used herein, refers to the axis that is intended to be used for focusing the image obtained by the optical assembly portion  205 . The controllable motor  294 , when used, is connected to the input/output interface  130  via a signal line  296 . 
     As shown in  FIG. 2 , in various exemplary embodiments, the control system portion  120  includes a controller  125 , an input/output interface  130 , a memory  140 , a workpiece program generator and executor  170 , a CAD file feature extractor  180 , and a power supply portion  190 . It will be appreciated that each of these components, as well as the additional components described below, may be interconnected by one or more data/control buses and/or application programming interfaces, or by direct connections between the various elements. 
     The input/output interface  130  includes an imaging control interface  131 , a motion control interface  132 , a lighting control interface  133 , and a lens control interface  134 . The motion control interface  132  includes a position control element  132   a , and a speed/acceleration control element  132   b . However, it should be appreciated that in various exemplary embodiments, such elements may be merged and/or indistinguishable. The lighting control interface  133  includes lighting control elements  133   a - 133   n , which control, for example, the selection, power, on/off switch, and strobe pulse timing if applicable, for the various corresponding light sources of the machine vision inspection system  100 , such as the light sources  220 ,  230 , and  240 . 
     The memory  140  includes an image file memory portion  141 , a workpiece program memory portion  142  that may include one or more part programs, or the like, and a video tool portion  143 . The video tool portion  143  includes tool portions  143   a - 143   m , which determine the GUI, image processing operation, etc., for each of the corresponding tools. Each of the tool portions  143   a - 143   m  includes respective mode portions that determine its behavior depending on whether or not that tool is activated in that particular mode. For example, the tool portion  143   a  includes a multi-click-plus operations portion  143   aa  that determines the behavior of the tool when it is activated in a multi-click-plus mode, described in greater detail below, a drag-and-draw operations portion  143   ab  that determines the behavior of the tool when it is activated in a known drag-and-draw mode, and a one-click operations portion  143   ac  that determines the behavior of the tool when it is activated in a known one-click mode. Any or all of the other tools of the video tool portion  143  may include similar mode portions, for example the final tool portion  143   m  similarly includes a multi-click-plus operations portion  143   ma , a drag-and-draw operations portion  143   mb , and a one-click operations portion  143   mc . The video tool portion  143  also includes a tool mode control memory portion  143   t  that governs the overall selection and operation of the respective tools modes referred to above. The video tool portion  143  also includes a region of interest generator  143   x  that supports automatic, semi-automatic and/or manual operations that define various regions of interest that are operable in various video tools included in the video tool portion  143 . 
     In general, the memory portion  140  stores data usable to operate the vision system components portion  200  to capture or acquire an image of the workpiece  20  such that the acquired image of the workpiece  20  has desired image characteristics. The memory portion  140  further stores data usable to operate the machine vision inspection system  100  to perform various inspection and measurement operations on the acquired images, either manually or automatically, and to output the results through the input/output interface  130 . The memory portion  140  also contains data defining a graphical user interface operable through the input/output interface  130 . 
     The signal lines or busses  221 ,  231  and  241  of the stage light  220 , the coaxial light  230 , and the surface light  240 , respectively, are all connected to the input/output interface  130 . The signal line  262  from the camera system  260  and the signal line  296  from the controllable motor  294  are connected to the input/output interface  130 . In addition to carrying image data, the signal line  262  may carry a signal from the controller  125  that initiates image acquisition. 
     One or more display devices  136  and one or more input devices  138  can also be connected to the input/output interface  130 . The display devices  136  and input devices  138  can be used to display a user interface, which may include various graphical user interface (GUI) features that are usable to perform inspection operations, and/or to create and/or modify part programs, to view the images captured by the camera system  260 , and/or to directly control the vision system components portion  200 . In a fully automated system having a predefined part program (or workpiece program), the display devices  136  and/or the input devices  138  may be omitted. 
     With regard to the CAD file feature extractor  180 , information, such as a CAD file representing a workpiece is frequently available in industrial applications of machine vision inspection systems. The locations of edges and boundaries in the CAD file representation may be determined manually, in a semi-automated fashion, or fully automatically, in such information may be useful for workpiece programming or navigating to a desired workpiece feature. 
     In various exemplary embodiments, when a user utilizes the machine vision inspection system  100  to create a workpiece image acquisition program for the workpiece  20 , the user generates workpiece program instructions either by explicitly coding the instructions automatically, semi-automatically, or manually, using a workpiece programming language, or by generating the instructions by moving the machine vision inspection system  100  through an image acquisition training sequence such that the workpiece program instructions capture the training sequence. This process is repeated for multiple images in a set of images that are to be captured. These instructions, when executed, will cause the machine vision inspection system to manipulate the workpiece stage  210  and/or the camera system  260  at certain speed(s) such that a particular portion of the workpiece  20  is within the field of view of the camera system  260  and at a desired focus state for each of a set of images to be acquired. In addition to the program instructions that control the relative movement of the camera and the workpiece, the workpiece image acquisition program also needs to include program instructions that activate one or more of the light sources  220 - 240  to provide a desired illumination of the workpiece  20  during each image acquisition. 
     Once a set of workpiece image acquisition instructions are defined, the control system  120  executes the instructions and commands the camera system  260  to capture one or more images of the workpiece  20  according to the instructions. The control system  120  will then, under control of the controller  125 , input the captured image(s) through the input/output interface  130  and store the captured image(s) in the memory  140 . The controller  125  may also display the captured images on the display device  136 . 
     The control system portion  120  is further usable to recall captured and stored workpiece inspection images, to inspect and analyze workpiece features in such workpiece inspection images, and to store and/or output the inspection results. These analysis and inspection methods are typically embodied in various video tools included in the video tool portion  143  of the memory  140 . Some of these tools, including edge detection tools, shape or pattern matching tools, dimension measuring tools, coordinate matching tools, auto focus tools, and the like, for example, are routinely available in a variety of commercially available machine vision inspection systems, such as the QUICK VISION® series of vision systems and the associated QVPAK® software, discussed above. The various methods disclosed herein may be applied to define the video tool parameters used these and other video tools in a novel and more convenient manner. For example, parameters associated with the edge/boundary detection tools disclosed in co-pending and commonly assigned U.S. patent application Ser. No. 09/987,986, filed Nov. 16, 2001, and the improved autofocus tools and methods described in co-pending U.S. patent application Ser. No. 10/719,210, filed Nov. 24, 2003, each of which is hereby incorporated by reference in its entirety, may also be defined according to the methods and user interface features disclosed herein. 
     After the image inspection/analysis operation using one or more of these video tools is completed, the control system  120  outputs the results of each analysis/inspection operation to the input/output interface for outputting to various display devices  136 , such as a video display, printer, and the like. The control system  120  may also store the results of each inspection operation in the memory  140 . 
       FIGS. 3A-3C  are diagrams illustrating the operation of an exemplary box tool  300  according to this invention, on an imperfect edge feature  310 . In  FIGS. 3A-3C , as well as figures described below, shading lines typified by the shading lines  395  are provided for purposes of illustration, to indicate which side of the edge feature  310 , or another edge feature illustrated herein, is darker in an image. This edge characteristic is significant for many edge finding video tools that include a parameter that indicates whether the tool operations should search for an edge feature that transitions from a dark-to-light region, or light-to-dark region, along a particular scan direction, as will be described in more detail below. 
     In operation, in an exemplary tool mode referred to as “multi-click-plus” herein, when the box tool icon on a video tool bar is selected, as described below with reference to  FIG. 11 , a box tool indicator  320 , as shown in  FIG. 3A , may appear on the display. The box tool indicator  320  may be associated with a cursor, which may appear as a cross-hair, or the like at a “cursor point”. The cursor point may provide coordinates that are used by the box tool to determine various parameters of the box tool and/or to adjust various features or parameter indicators of the box tool GUI, as described in greater detail below. In general, for the various tools shown and described herein, a tool indicator may continue to appear adjacent to the cursor throughout various operations described herein, even if it is omitted from a figure in order to more clearly illustrate other features of the figure. 
     In the example shown in  FIG. 3A , the user initially places a point  1  along the edge feature  310  at a desired position  330 , which bounds one end of the box tool height, that is, the height of the box tool region of interest  350  (box tool ROI  350 ), shown in  FIGS. 3B and 3C . Unless otherwise indicated by description or context, throughout this disclosure, “placing a point” may generally comprise the user entering the coordinates of a desired point, to be used by a video tool for determining one or more video tool parameters. In this way the user may control the determination or definition of various video tool parameters. For example, in exemplary embodiments, the user may generally move an input device, such as a mouse, joystick, trackball, or the like, to move the cursor around on a display of a feature such as the edge feature  310 . When the user has positioned the cursor at a desired position, the user may then click an input device button, or press “enter” on a keyboard, or the like, in order to “place a point” at the desired position. Placing a point may anchor a tool parameter indicator at the position of the placed point, as described below. 
     After placing the point  1 , a parameter indicator, such as a crosshair, may be anchored at the point  1 , and the user may then continue to move the cursor  335 , which, in some embodiments, may be connected to the parameter indicator anchored at point  1  (at position  330 ) by a dotted construction line  332 , that may follow the cursor  335  like a taut elastic band. In other embodiments, the construction line is not included, and the cursor may act as a parameter indicator. As shown in  FIG. 3A , the user has moved the cursor  335  to a second point along the edge feature  310 , which tentatively bounds the other end of the box tool ROI height. The cursor, or the moving end of the construction line  332 , may be regarded as a parameter indicator, since it is reflecting a potential dimension of a region of interest of the box tool  300 , which will be fixed when the user places a second point, as described below. In exemplary embodiments, a parameter indicator (e.g. the end of the construction line, or a cross-hair associated with the cursor position, or the like) may be automatically linked to be dynamically adjusted based on the cursor position (which is controlled by the user&#39;s input device movement), without requiring the user to take, or maintain, any special action. That is, “automatic linking”, as the term is used herein, means that the user need not “select” the dynamically adjusted parameter indicator with an additional mouse click after placing the preceding point, and/or the user need not continue to depress and/or hold down a mouse button, or other input device button, or the like, to “drag” the dynamically adjusted parameter indicator, or the like. 
     Regarding “automatic linking”, automatic linking is one feature that makes the box tool  300 , and various other tools described herein, particularly convenient to use, and in conjunction with the appearance and operation of the parameter indicators shown and described herein, particularly intuitive to learn and use. In embodiments where automatic linking is used, the need for the user to “select” a dynamically adjusted parameter indicator, is eliminated, which provides that an operation such as a “button click” may be reserved to operate exclusively as an operation that places a point while the video tool parameters are being established by the user. Otherwise, a “click” might be required to select a parameter indicator that is to dynamically follow the cursor, or the like. Thus, the user may learn more quickly by associating one operation (e.g., a “click”) with one function (placing a point) while operating the video tool GUI. Furthermore, in other conventional “drag and draw” operations, a first point (e.g., a box corner) is “placed” by depressing a mouse button, or the like, then the button must be held in an unstable depressed state while moving to a next desired location (e.g., the other corner of the box), and then the next desired location is placed by releasing the button. Thus, two sequential placed points are placed by two different actions. In contrast, automatic linking provides that all sequentially placed points may be placed by the same type of operation, and that a button need not be held in an unstable state. Thus, in embodiments that use automatic linking, the user may avoid an unstable ergonomic state, and may also learn more quickly by associating one type of operation (e.g., a “click”) with one function (e.g., placing a point) while operating the video tool GUI. 
     Continuing, as shown in  FIG. 3B , the user places a point  2  at a position  340 , which anchors the other end of the box tool ROI height (or longitudinal dimension) and may cause other parameter indicators of the box tool  300  to appear and be automatically linked to be dynamically adjusted based on the cursor position. The term “parameter indicators” is used herein to refer to the graphical features of the user interface of a video tool, or a video tool GUI, that correspond to the current user-determined, or machine determined or derived, or default tool parameters. For example, the parameter indicators shown in  FIGS. 3B and 3C  may include the upper end, lower end, and sides of the ROI box  350 B, the scan direction arrows  370 , the midline indicator  342 , the sampling direction indicator (which is the upward pointing arrowhead located along the midline  342  at the position  340 ), the edge selector location indicator  385  (also called the selector location indicator  385 ), and the rising/falling indicator  360 . The rising/falling indicator  360  is empty, indicating that the rising/falling direction has not yet been determined in  FIG. 3B . At various times, the cursor display may be merged with, or indistinguishable from, various parameter indicators of the video tool GUI. This might alternatively be described, or implemented, as using the cursor as a parameter indicator in the GUI at various times, or as the cursor representation changing to indicate various parameters, or as the various parameter indicators “following” the cursor. All of these descriptions may fall within the scope of this invention, if they serve to implement the various features and operations of the invention outlined herein. 
     Regarding “linking” in general, as the term is used herein, for some “linked” parameter indicators, they may be dynamically adjusted to follow the cursor position. For some linked parameter indicators, they may be dynamically adjusted in a manner depending on the cursor position, without following the cursor. As one example, a first side of the ROI box  350 B may be dynamically adjusted to follow the cursor position, while the other side of the ROI box  350 B may dynamically adjusted to a location symmetric to first side, about the centerline  342  of the box tool  300 . As another example, the direction of the scan direction arrows  370  may dynamically adjusted based on the cursor position (e.g., to point along a direction that is from the centerline toward the cursor position), regardless of their location, which may be an anchored location. As another example, the location of the edge selector location indicator  385  may be dynamically adjusted to parallel the cursor position, while being restricted to travel along the centerline  342 . 
     For the example shown in  FIG. 3B , when point  2  is placed, thereafter the video tool  300  determines the width (or lateral dimension) of the ROI box  350 B as being located symmetrically about the centerline  342  joining point  1  and point  2 . Also, the point placement sequence determines a sampling direction proceeding from point  1  to point  2 , as indicated by the upward-pointing sampling direction arrow at the position  340 . The sampling direction is the direction that data sampling and/or analysis follows when determining a series of edge points along the edge feature  310 . 
     After placing point  2 , the user may continue to move the cursor  335 . In exemplary embodiments, the automatically linked parameter indicators may be dynamically adjusted based on the cursor position without requiring the user to depress and/or hold down a mouse button. As shown in  FIG. 3B , after placing point  2 , and the appearance of the various parameter indicators discussed above, the user has moved the cursor  335  to a point down and to the left from point  2 , and the automatically linked width of the ROI box  350 B, selector location indicator  385 , and scan direction arrows  370 , have been dynamically adjusted accordingly. 
     It should be appreciated that the linked width of the ROI box  350 B, the linked selector location indicator  385 , and the linked scan direction arrows  370 , may all be linked and dynamically adjusted at the same time. Linking a plurality of different types of parameter indicators to be dynamically adjusted at the same time is another feature that makes the box tool  300 , and various other tools described herein, particularly convenient to use, and, in conjunction with the appearance and operation of the parameter indicators shown and described herein, particularly intuitive to learn and use. This may be the case, even if the plurality of different types of parameter indicators are linked by operations that are not automatic. However, the combination of automatically linking a plurality of different parameter indicators to be dynamically adjusted at the same time is particularly convenient and intuitive, and may be preferred in many embodiments. 
     Regarding the positioning of the edge selector location indicator  385 , the edge feature  310  is shown to include a deviating portion  315 . Edge deviations, such as the deviating portion  315 , may generally create potential problems for properly training an edge-finding tool. It will be appreciated that workpiece edges in actual workpiece images may exhibit significant variations along the edge, due to lighting or shadow variations, contamination effects, diffraction effects, and the like. For example, diffraction effects and/or shadows may frequently create a closely-spaced “family” of edge-like image features adjacent to the true workpiece edge location in the image. Properly “training” an edge tool during learn mode operations is critical to locating the proper edge among these potential erroneous edge-like features, during subsequent inspection operations. During training, an edge tool analyzes the pixel intensity variations along a scan line, and determines and records the particular intensity variation characteristics that correspond to the desired edge. For example, these characteristics may be based on the total intensity variation across the edge, the rate of change of the intensity variation across the edge, whether the intensity variation is rising or falling across the edge for a particular scan direction, whether the intensity variation is the first, second, third, etc. rising or falling variation along the scan line, etc. An edge tool may be “trained” by automatically determining and recording these characteristics by analyzing a desired “prototypical” edge scan. In various embodiments, a user may pick the desired location for the prototypical edge scan by locating the selector location indicator  385  on the desired edge, preferably at a location that is relatively free of contamination, optical aberrations, and the like. In  FIG. 3B , for purposes of illustration, the cursor  335  has been temporarily located at a point such that the linked selector location indicator  385 , which may traverse along the centerline  342  to parallel the location of the cursor  335 , is located slightly away from the edge  310  due to the deviating portion  315 . Such a selector location may lead to erroneous training. 
     As shown in  FIG. 3C , the user has continued to move the cursor  335  and the automatically linked width of the ROI box  350 B, selector location indicator  385 , and scan direction arrows  370 , have been dynamically adjusted accordingly. The selector location now coincides with a desired prototypical scan location on the edge  310 , and the scan direction arrows  370  point along a desired direction. Since the cursor  335  is on the right side of the centerline  342 , the arrows  370  are shown to be pointing from left to right. Regarding the scan direction, for increased reliability it is generally advantageous to determine the scan direction to proceed from a region where the intensity is more uniform to a region that may have more intensity variation (due to texture or image noise, for example), such that a desired edge transition characteristic is determined along a scan line before unpredictable “noise” characteristics are encountered. 
     When the user places point  3 , various parameter indicators are anchored and/or fixed based on the position of the placed point  3 , and any previously undetermined tool parameters associated with the final set of parameter indicators are determined and used such that the tool may be run to automatically teach or train the tool. After the tool is trained, the rising/falling indicator  360  may be automatically filled with dark and light regions as shown in  FIG. 3C , reflecting the direction of the dark-to-light transition that was determined by the tool operations during training. Subsequently, a series of edge points that are detected along the edge  310  based on the trained parameters may be marked on the display, for example using the known methods employed in commercially available machine vision systems. The user may then accept the training results and continue to other operations, or reject the training results, further modify the tool parameters, and retrain the tool until satisfactory results are achieved. 
     It should be appreciated that in various embodiments, an auto-trace tool, such as that indicated in  FIG. 12A , and included in various commercial machine vision inspection systems, may include tool parameters that may be defined by operations substantially similar to those previously described with reference to the box tool  300 . Thus, it should be appreciated that one skilled in the art may design and operate an auto-trace tool based on this disclosure in conjunction with known auto-trace tool techniques found in commercially available machine vision inspection systems. 
       FIG. 4  is a diagram illustrating an advantage of the operation of the box tool  300  on an edge feature  410  with an interruption  420 . As will be described in more detail below, the operation of the box tool  300  in accordance with the present invention is advantageous in that edge features with unusual characteristics (e.g., a notch or protrusion) can be readily accommodated with a small or minimum number of user actions. The operation of the box tool  300  of  FIG. 4  is similar to the operation of the box tool  300  as described above with respect to  FIGS. 3A-3C . The three points  1 ,  2 , and  3 , are placed at the locations  330 ,  340 , and  380 ′, in a manner similar to that described above. However, in the example shown in  FIG. 4 , it is desired to find the location of the straight portion of the edge  410  that does not include the interruption  420 . Thus, the point  3  is placed at a location  380 ′ that insures that the interruption  420  will not disturb the training of the box tool  300  or subsequent edge finding operations. In particular, the point  3  is placed such that the linked width dimension of the box tool ROI  350  is adjusted so as to exclude the interruption  420  and such that the linked selector location indicator  385  is located at a desired location away from the interruption  420  on the straight portion of the edge  410 , so that the trained box tool  300  will operate as desired. It should be appreciated that the width of the box tool ROI  350  and the selector location indicator  385  are both automatically linked to be dynamically adjusted based on the cursor location as described with reference to  FIG. 3C , and finally to be anchored based on the placed point  3  as shown in  FIG. 4 , such that they both avoid the interruption  420  with a single user action that anchors point  3 . 
       FIGS. 5A-5D  are diagrams illustrating the operation of a circle tool  500  on a circular edge feature  510 . The operation of the various features of the circle tool  500  are analogous to the similar features of the box tool  300  as described above with respect to  FIGS. 3A-3C , unless otherwise indicated by description or context. In operation, in a tool mode referred to as “multi-click-plus” herein, when the circle tool icon on a video tool bar is selected, as described below with reference to  FIG. 11 , a circle tool indicator  520 , as shown in  FIG. 5A , may appear on the display. The circle tool indicator  520  may be associated with a cursor point, as previously described with reference to the box tool indicator  320 . In the example shown in  FIG. 5A , the user initially places a point  1  along the edge feature  510  at a desired position  530 . After placing the point  1 , a parameter indicator, such as a crosshair, may be anchored at the point  1 , and the user may then continue to move the cursor  535 , which, in some embodiments, may be connected to the parameter indicator anchored at point  1  (at position  530 ) by a dotted construction line  532 , that may follow the cursor  535  like a taut elastic band. The moving end of the construction line  532 , may be regarded as a parameter indicator that is automatically linked to be dynamically adjusted based on the cursor position. In exemplary embodiments, the construction line  532  may follow the cursor position without requiring the user to depress and/or hold down a mouse button. As shown in  FIG. 5A , the user has moved the cursor  535  to a second point along the edge feature  510 . 
     Continuing, as shown in  FIG. 5B , the user places a point  2  at a position  540  on the edge feature  510 , which may anchor another parameter indicator and may cause other parameter indicators of the circle tool  500 , such as the provisional circle construction line  532 ′, to appear. After placing point  2 , the user may continue to move the cursor  535 . In the example shown in  FIG. 5B , after placing point  2 , the provisional circle construction line  532 ′, is automatically linked to be dynamically adjusted to be best fit to point  1 , point  2 , and the position of the cursor  535 , without requiring the user to depress and/or hold down a mouse button after placing point  2 . 
     Continuing, as shown in  FIG. 5C , the user places a point  3  at a position  580  on the edge feature  510 , which may anchor another parameter indicator and/or and may cause other parameter indicators of the circle tool  500  to appear. The provision circle construction line  532 ′ may be replaced by, or dynamically adjusted to become, an anchored nominal circle indicator  542  which is also the circle tool ROI centerline indicator  542 . The nominal circle indicator  542  may have a radius and center location that are best fit to point  1 , point  2  and point  3 , and that nominally approximates the edge feature  510 . A sampling direction may proceed around the circle in the direction from point  1  to point  2 , as indicated by an anchored sampling direction indicator, the arrowhead  552 , pointing counterclockwise on the circle tool ROI centerline indicator  542 . Other exemplary parameter indicators shown in  FIG. 5C  include the circle tool ROI interior radius or diameter  550 I and exterior radius or diameter  550 E, a scan direction arrow  570 , a selector location indicator  585 , and a rising/falling indicator  560 . In exemplary embodiments, these other parameter indicators may be automatically linked to be dynamically adjusted based on the cursor position, without requiring the user to depress and/or hold down a mouse button. 
     For the example shown in  FIG. 5C , when point  3  is placed, thereafter the automatically linked radial dimension of the circle tool ROI  550 , the selector location indicator  585 , and the radial edge scan orientation indicated by the scan direction indicator arrow  570  are dynamically adjusted based on the cursor position. The radial edge scan orientation may be a function of the location of the cursor  535  relative to the circle tool ROI centerline indicator  542 . In the example shown in  FIG. 5C , the user has moved the cursor  535  to a point down from the placed point  3 , and the location of the ROI diameter  550 E, the radial dimension of the circle tool ROI  550 , selector location indicator  585 , and scan direction arrows  570 , have been dynamically adjusted accordingly. Since the location of the cursor  535  is outside of the circle tool ROI centerline indicator  542 , the scan direction as indicated by the scan direction indicator arrow  570  is radially outward, whereas if the cursor  535  was moved inside the circle tool ROI centerline indicator  542 , the scan direction would be reversed. In the embodiment shown in  FIG. 5C , the exterior diameter  550 E is dynamically adjusted to follow the cursor  535 , and the radial dimension of the circle tool ROI  550  is dynamically adjusted symmetrically about the ROI centerline indicator  542 . However, in other exemplary embodiments, the circle tool ROI interior diameter  550 I and/or exterior diameter  550 E may be subsequently or independently adjusted such that the radial dimension of the circle tool ROI  550  is not symmetrical about the ROI centerline indicator  542 . 
     As shown in  FIG. 5D , the user has continued to move the cursor  535  to the location  590 , and the automatically linked radial dimension of the circle tool ROI  550 , selector location indicator  585 , and scan direction arrow  570 , have been dynamically adjusted accordingly. The location of the selector location indicator  585  now coincides with a desired prototypical scan location on the edge feature  510 , and the scan direction arrow  570  is oriented along the desired radial direction. 
     When the user places point  4  at the location  590 , various parameter indicators are anchored and/or fixed based on the position of the placed point  4 , and any previously undetermined tool parameters associated with the final set of parameter indicators are determined and used such that the tool may be run to automatically teach or train the tool. After the tool is trained, the rising/falling indicator  560  may be automatically filled with dark and light regions as shown in  FIG. 5D , reflecting the direction of the dark-to-light transition that was determined by the tool operations during training. Subsequently, a series of edge points that are detected along the edge feature  510  based on the trained parameters may be marked on the display, for example using the known methods employed in commercially available machine vision systems. The user may then accept the training results and continue to other operations, or reject the training results, further modify the tool parameters, and retrain the tool until satisfactory results are achieved. 
       FIG. 6  is a diagram illustrating an advantage of the operation of the circle tool  500  on a circular edge feature  610  with an interruption  620 . As will be described in more detail below, the operation of the circle tool  500  in accordance with the present invention is advantageous in that circular edge features with unusual characteristics (e.g., a notch or protrusion) can be readily accommodated with a small or minimum number of user actions. The operation of the circle tool  500  of  FIG. 6  is similar to the operation of the circle tool  500  as described above with respect to  FIGS. 5A-5D . The three points  1 ,  2 , and  3 , are placed at the locations  530 ,  540 , and  580 , in a manner similar to that described above. However, in the example shown in  FIG. 6 , it is desired to find the location of the circular portion of the edge feature  610  that does not include the interruption  620 . Thus, the point  4  is placed at a location  590 ′ that insures that the interruption  620  will not disturb the training of the circle tool  500  or subsequent edge finding operations. In particular, the point  4  is placed such that the linked radial dimension of the circle tool ROI  550  is adjusted so as to exclude the interruption  620 , and such that the linked selector location indicator  585  is located at a desired location away from the interruption  620  on a portion of the desired edge feature  610 , so the trained circle tool  500  will operate as desired. It should be appreciated that the radial dimension of the circle tool ROI  550  and the selector location indicator  585  are both automatically linked to be dynamically adjusted based on the cursor location as described with reference to  FIG. 5C , and finally to be anchored based on the placed point  4  as shown in  FIG. 6 , such that they both avoid the interruption  620  with a single user action that anchors point  4 . 
       FIGS. 7A-7D  are diagrams illustrating the operation of an arc tool  700  on an arc-shaped edge feature  710 . The operation of the various features of the arc tool  700  are analogous to the similar features of the circle tool  500  as described above with respect to  FIGS. 5A-5D , unless otherwise indicated by description or context. In operation, in a tool mode referred to as “multi-click-plus” herein, when the arc tool icon on a video tool bar is selected, as described below with reference to  FIG. 11 , an arc tool indicator  720 , as shown in  FIG. 7A , may appear on the display. The arc tool indicator  720  may be associated with a cursor point, as previously described with reference to the box tool indicator  320 . In the example shown in  FIG. 7A , the user initially places a point  1  at a desired position  730  at one end of the arc on the edge feature  710 . After placing the point  1 , a parameter indicator, such as a crosshair, may be anchored at the point  1 , and the user may then continue to move the cursor  735 , which may be connected to the parameter indicator anchored at point  1  (at position  730 ) by a dotted construction line  732 , that may follow the cursor  735  like a taut elastic band. The moving end of the construction line  732 , may be regarded as a parameter indicator that is automatically linked to be dynamically adjusted based on the cursor position. In exemplary embodiments, the construction line  732  may follow the user&#39;s mouse movement without requiring the user to depress and/or hold down a mouse button. As shown in  FIG. 7A , the user has moved the cursor  735  to a second point along the edge feature  710 . 
     Continuing, as shown in  FIG. 7B , the user places a point  2  at a position  740  on the edge feature  710 , which may anchor another parameter indicator and may cause other parameter indicators of the arc tool  700 , such as the provisional arc construction line  732 ′, to appear. After placing point  2 , the user may continue to move the cursor  735 . In the example shown in  FIG. 7B , after placing point  2 , the provisional arc construction line  732 ′ is automatically linked to be dynamically adjusted to be best fit to point  1 , point  2 , and the position of the cursor  735 , without requiring the user to depress and/or hold down a mouse button after placing point  2 . In other embodiments, the construction line is not included, and the cursor may act as a parameter indicator. The cursor, or the moving construction line  732 ′, may be regarded as a parameter indicator, since it is reflecting a potential parameter of a region of interest of the arc tool  700 , which will be fixed when the user places a third point, as described below. 
     Continuing, as shown in  FIG. 7C , the user places a point  3  at a desired position  780  at the other end of the arc on the edge feature  710 , which may anchor another parameter indicator and/or and may cause other parameter indicators of the arc tool  700  to appear. The provisional arc construction line  732 ′ may be replaced by, or dynamically adjusted to become, an anchored nominal arc indicator  742 , which is also the arc tool ROI centerline indicator  742 . The nominal arc indicator  742  may have a radius and center location that are best fit to point  1 , point  2  and point  3 , and that nominally approximates the edge feature  710 . A sampling direction may proceed around the arc in the direction from point  1  to point  2 , as indicated by an anchored sampling direction indicator, the arrowhead  752 , pointing counterclockwise on the arc tool ROI centerline indicator  742 . Other exemplary parameter indicators shown in  FIG. 7C  include the arc tool ROI interior radius  750 I and exterior radius  750 E, scan direction arrows  770 , a selector location indicator  785 , and a rising/falling indicator  760 . In exemplary embodiments, these other parameter indicators may be automatically linked and dynamically adjusted based on the cursor position, without requiring the user to depress and/or hold down a mouse button, similarly to the analogous elements of the circle tool  500 . In the example shown in  FIG. 7C , the user has continued to move the cursor  735  to a point down from the placed point  3 , and the location of the ROI diameter  550 E, the radial dimension of the arc tool ROI  750 , the selector location indicator  785 , and the scan direction arrows  770 , have been dynamically adjusted accordingly, similarly to the analogous elements of the circle tool  500 . 
     As shown in  FIG. 7D , the user has continued to move the cursor  735  and places a point  4  at the location  790 , and the automatically linked radial dimension of the arc tool ROI  750 , selector location indicator  785 , and scan direction arrows  770 , have been dynamically adjusted accordingly. The location of the selector location indicator  785  now coincides with a desired prototypical scan location on the edge feature  710 , and the scan direction arrow  770  is oriented along the desired radial direction. When the user places point  4  at the location  790 , various parameter indicators are anchored and/or fixed based on the position of the placed point  4 , and any previously undetermined tool parameters associated with the final set of parameter indicators are determined and used such that the tool may be run to automatically teach or train the tool. After the tool is trained, the rising/falling indicator  760  may be automatically filled with dark and light regions as shown in  FIG. 7D , reflecting the direction of the dark-to-light transition that was determined by the tool operations during training. Subsequently, a series of edge points that are detected along the edge feature  710  based on the trained parameters may be marked on the display, for example using the known methods employed in commercially available machine vision systems. The user may then accept the training results and continue to other operations, or reject the training results, further modify the tool parameters, and retrain the tool until satisfactory results are achieved. 
       FIGS. 8A-8C  are diagrams illustrating the operation of an edge auto focus tool  800  on an edge feature  810 . In operation, in a tool mode referred to as “multi-click-plus” herein, when the edge auto focus tool icon on a video tool bar is selected, as described below with reference to  FIG. 11 , an edge auto focus tool indicator  820 , as shown in  FIG. 8A , may appear on the display. The edge auto focus tool indicator  820  may be associated with a cursor point, as previously described with reference to the box tool indicator  320 . In the example shown in  FIG. 8A , the user initially places a point  1  along the edge feature  810  at a desired position  830 , which indicates that the edge feature  810  is the target that should be used for the auto focus operations, and also bounds one end of a dimension of the auto focus tool ROI box  850  (shown in  FIGS. 8B and 8C .) In the example shown in  FIGS. 8A-8C , the point  1  bounds one end of the ROI “height” (or longitudinal dimension), while in other embodiments or examples, the point  1  may bound one end of the ROI “width” (which may still be regarded as the longitudinal dimension of the ROI), generally depending on the orientation on the edge feature  810  and the corresponding orientation of the edge auto focus tool  800 . After placing the point  1 , a parameter indicator, such as a crosshair, may be anchored at the point  1 , and the user may then continue to move the cursor  835 , which may be connected to the parameter indicator anchored at point  1  (at position  830 ) by a dotted construction line  832  and an orthogonal solid construction line  832 ′, that may dynamically follow the cursor  835 . The moving end of the construction line  832  and/or the orthogonal solid construction line  832 ′, may be regarded as a parameter indicator that is automatically linked to be dynamically adjusted based on the cursor position. In exemplary embodiments, these parameter indicators may be dynamically adjusted to follow the cursor position without requiring the user to depress and/or hold down a mouse button. In operation, it is desirable for the user to approximately align the dotted construction line  832  (horizontally or vertically) with the edge feature  810 . 
     As shown in  FIG. 8A , the user has moved the cursor  835  to a second point below and to the right of the point  1 , which tentatively bounds the other end of the dimension of the auto focus tool ROI box  850  that is bounded by point  1 . Also shown in  FIG. 8A  are four quadrants A, B, C, and D, depicted relative to the point  1 , which play a role in an operation outlined below. The four quadrants need not be displayed to the user. 
     Continuing, as shown in  FIG. 8B , the user places a point  2  at a position  840 . Placing the point  2  may anchor the other end of the dimension of the auto focus tool ROI box  850  that is bounded by point  1 , may optionally cause an associated parameter indicator to appear at point  2 , and may cause other parameter indicators of the auto focus tool  800 , such as the entire ROI box  850 , to appear. In the example shown in  FIG. 8B , after placing point  2 , the left side and the upper side of the ROI box  850  are anchored, and the right side and the bottom side of the ROI box  850  are automatically linked to be dynamically adjusted based on the position of the cursor  835 , without requiring the user to depress and/or hold down a mouse button after placing point  2 . After placing point  2 , the user may continue to move the cursor  835 . Other exemplary parameter indicators shown in  FIG. 8B  include the auto focus tool ROI box  850 , a scan direction arrow  870 , and a rising/falling indicator  860 . The scan direction may be determined based on which of the four quadrants A, B, C, and D the point  2  falls in, for example, from left to right in quadrant D, from down to up in quadrant A, from right to left in quadrant B, and from up to down in quadrant C. 
     Continuing, as shown in  FIG. 8C , the user places a point  3  at a position  880  and the width dimension of the auto focus tool ROI is dynamically adjusted, and anchored, accordingly. Placing the point  3  may anchor the entire auto focus tool ROI box  850 . In the example shown in  FIGS. 8B and 8C , the left end of the ROI width dimension is located at a default distance away from the dashed construction line  832  that is based on the distance of the point  2  from the dashed construction line  832 . The right end of the ROI width dimension is then determined by the point  3 . However, in other embodiments, the width dimension may simply be located symmetrically around the location of the dashed construction line  832 , based on the location of the point  3 . When the user places point  3  at the location  880 , various parameter indicators are anchored and/or fixed based on the position of the placed point  3 , and any previously undetermined tool parameters associated with the final set of parameter indicators are determined and used such that the tool may be run to automatically teach or train the tool. After the tool is trained, the rising/falling indicator  860  may be left blank, indicating that the rising/falling parameter is not an essential tool parameter for the edge auto focus tool  800 . However, if desired, the rising/falling parameter may be set by a user subsequently editing the tool, in a related menu or window of the edge auto focus tool user interface. In such a case, the rising/falling indicator  860  may be filled in accordingly, to indicate the rising/falling parameter is now set, and will be used. Subsequently, an autofocus operation may be performed based on the trained parameters using the known methods employed in commercially available machine vision systems. The user may then accept the training results and continue to other operations, or reject the training results, further modify the tool parameters, and retrain the tool until satisfactory results are achieved. 
       FIGS. 9A-9C  are diagrams illustrating the operation of a dual area contrast (DAC) tool  900  around an edge feature  910 . Teachings related to the purpose and general functions underlying the DAC tool  900  are disclosed in U.S. Pat. No. 6,542,180 to Wasserman and Tessadro (the &#39;180 patent), which is incorporated herein by reference in its entirety. In operation, in a tool mode referred to as “multi-click-plus” herein, when the DAC tool icon on a video tool bar is selected, as described below with reference to  FIG. 11 , a DAC tool indicator  920 , as shown in  FIG. 9A , may appear on the display. The DAC tool indicator  920  may be associated with a cursor point, as previously described with reference to the box tool indicator  320 . In the example shown in  FIG. 9A , the user initially places a point  1  along the edge feature  910  at a desired position  930 , which indicates that the DAC tool ROI&#39;s  950 L and  950 R (shown in  FIGS. 9B and 9C ) should be distributed about the edge feature  910 , and also bounds one end of a longitudinal dimension (along the vertical direction in this case) of the DAC tool ROI&#39;s  950 L and  950 R. After placing the point  1 , a parameter indicator, such as a crosshair, may be anchored at the point  1 , and the user may then continue to move the cursor  935 , which may be connected to the parameter indicator anchored at point  1  (at position  930 ) by a dotted construction line  932 , that may follow the cursor  935  like a taut elastic band. The moving end of the construction line  932 , may be regarded as a parameter indicator that is automatically linked to be dynamically adjusted based on the cursor position. In exemplary embodiments, the construction line  932  may follow the cursor position without requiring the user to depress and/or hold down a mouse button. In operation, it is desirable for the user to approximately align the dotted construction line  932  with the edge feature  910 . As shown in  FIG. 9A , the user has moved the cursor  935  to a second point along the edge feature  910 , above the point  1 , which tentatively bounds the second end of the longitudinal dimension of the DAC tool ROI&#39;s  950 L and  950 R. 
     Continuing, as shown in  FIG. 9B , the user places a point  2  at a position  940 . Placing the point  2  may anchor the second end of the height (or longitudinal) dimension of the DAC tool ROI&#39;s  950 L and  950 R, the location of the centerline indicator  942 , may optionally cause an associated parameter indicator to appear at point  2 , and may cause other parameter indicators of the DAC tool  900  to appear. In the example shown in  FIG. 9B , after placing point  2 , the location of the upper sides and the lower sides of the DAC tool ROI&#39;s  950 L and  950 R are anchored, and the lateral dimensions of the DAC tool ROI&#39;s  950 L and  950 R, are automatically linked to be dynamically adjusted based on the position of the cursor  935 , without requiring the user to depress and/or hold down a mouse button after placing point  2 . After placing point  2 , the user may continue to move the cursor  935 . 
     Continuing, as shown in  FIG. 9C , the user places a point  3  at a position  980  and the lateral dimensions of the DAC tool ROI&#39;s  950 L and  950 R (their individual widths and lateral locations) are dynamically adjusted, and anchored, accordingly. In the example shown in  FIGS. 9B and 9C , the lateral distance of the “interior limits” of the ROI&#39;s  950 L and  950 R from the centerline indicator  942  is a symmetrical default distance. The lateral distance of the “exterior limits” of the ROI&#39;s  950 L and  950 R from the centerline indicator  942  is a symmetrical distance that corresponds to the location of the point  3 . However, in other embodiments, the lateral distance from the “interior limits” of the ROI&#39;s  950 L and  950 R from the centerline indicator  942 may simply be a proportion of the distance from the exterior limits to the centerline indicator  942 . 
     When the user places point  3  at the location  980 , various parameter indicators are anchored and/or fixed based on the position of the placed point  3 , and any previously undetermined tool parameters associated with the final set of parameter indicators are determined and used such that the tool may be run to automatically teach or train the tool. Subsequently, a light-adjusting operation may be performed based on the results of the trained DAC tool  900 , according to known methods employed in commercially available machine vision systems and/or as described in the &#39;180 patent. The user may then accept the lighting results and the DAC tool  900  training results and continue to other operations, or reject the training results, further modify the tool parameters, and retrain the tool until satisfactory results are achieved. 
       FIGS. 10A and 10B  are flow diagrams illustrative of one exemplary embodiment of a routine  1100  for operation of a multi-click-plus video tool. As shown in  FIG. 10A , at a block  1110 , a multi-click-plus video tool selection is input by a user (e.g., the user may click a desired video tool icon on a toolbar, with the multi-click-plus tool mode activated, if applicable). At block  1112 , the GUI display on the workpiece image is changed to correspond to the GUI for the selected video tool. At a block  1114 , the cursor is positioned to match a user input as the user positions the cursor on the image at a first desired location (e.g., based on mouse movement). 
     At a block  1116 , when the user places a first point at the first desired location (e.g., by the user making a click with a mouse button, while the cursor is at the first desired location), the video tool parameters associated with the first point are determined. In addition, one or more adjusted or added parameter indicators of the video tool GUI, corresponding to the entry of the first point, are displayed. One or more of the parameter indicators may be anchored. 
     At a block  1118 , after the user places the first point, one or more parameter indicators may be automatically linked to be dynamically adjusted based on the cursor position (e.g., as the cursor moves away from the first point.) In various embodiments, one or more of the automatically linked parameter indicators may be dynamically adjusted based on the cursor position without requiring the user to depress and/or hold down a mouse button after placing the first point. At a block  1120 , the cursor is positioned to match a user input as the user positions the cursor on the image at a second desired location (e.g., based on mouse movement). 
     At a block  1122 , when the user places a second point at the second desired location (e.g., by the user making a click with a mouse button, while the cursor is at the second desired location), the video tool parameters associated with the second point are determined. In addition, one or more adjusted or added parameter indicators of the video tool GUI, corresponding to the entry of the second point, are displayed. One or more of the of the parameter indicators may be anchored. 
     As shown in  FIG. 10B , from a point A the routine continues to a block  1150 . At block  1150 , after the user places the preceding point (e.g., the second point or a new point), one or more of the adjusted or added parameter indicators may be automatically linked to be dynamically adjusted based on the cursor position (e.g., as the cursor moves away from the second or new point.) In various embodiments, one or more of the automatically linked parameter indicators may be dynamically adjusted based on the cursor position without requiring the user to depress and/or hold down a mouse button after placing the second point. For example, when the multi-click-plus video tool is an edge-finding box tool, the first time that step  1150  is reached, after a second point is placed, a plurality of parameter indicators are may be automatically linked to be dynamically adjusted based on the cursor position. The plurality may include an edge “selector” location indicator, and an ROI dimension (or coordinate) indicator. A scan direction indicator may also be linked to be dynamically adjusted based on the cursor position. 
     At a block  1152 , the cursor is positioned to match a user input as the user positions the cursor on the image at a new desired location (e.g., a third or fourth desired location.) At a block  1154 , when the user places a new point at the new desired location (e.g., by the user making a click with a mouse button, while the cursor is at the new desired location), the video tool parameters associated with the new point are determined. In addition, one or more adjusted or added parameter indicators of the video tool GUI, corresponding to the entry of the new point, may be displayed. One or more of the of the parameter indicators may be anchored. If the new placed point is the final placed point required for determining the video tool parameters, an anchored and/or finalized set of video tool parameter indicators may be displayed. 
     At a decision block  1156 , a determination is made as to whether all of the user-determined video tool parameters have been identified. If all of the user-determined tool parameters have not yet been identified, then the routine returns to block  1150 , to perform operations for identifying additional tool parameters. For example, when the multi-click-plus video tool is an edge-finding arc or circle tool, the second time that step  1150  is reached, after a third point has been placed, a plurality of parameter indicators are may be automatically linked to be dynamically adjusted based on the cursor position. The plurality may include an edge “selector” location indicator, and an ROI dimension (or coordinate) indicator. A scan direction indicator may also be linked to be dynamically adjusted based on the cursor position. Otherwise, if all of the user-determined tool parameters have been identified, then the routine continues to a block  1158 . At a block  1158 , any remaining video tool parameters are automatically determined, and/or the video tool may be trained and/or run based on all the determined parameters. At a block  1160 , the results of running the trained video tool are recorded, displayed or output (e.g., during manual or learn mode operations) and/or if the results are acceptable, the determined and trained video tool parameters may be recorded or stored in a part program (e.g., during learn mode operations, if accepted by a user.) 
       FIG. 11  is a diagram illustrating a video toolbar  1200  from which various video tools and modes may be selected. As shown in  FIG. 11 , the toolbar  1200  includes selections for numerous video tools, including those described above with respect to  FIGS. 3-10 . The toolbar  1200  also includes selectors for various modes, including a selector  1212  for a known single click mode, a selector  1214  for a multi-click mode, a selector  1216  for a multi-click-plus mode. In operation, in one embodiment, after the user selects a selector it determines the active tool mode, and may stay highlighted to indicate the active tool mode, as exemplified by the multi-click-plus selector  1216  shown in  FIG. 11 . Thereafter, when one of the individual video tools is selected, it will operate according to the selected active mode. The selector  1218  is for a known “auto run” mode, that may be activated in conjunction with other modes. In auto run mode, when the final user-determined video tool data is entered, the video tool automatically runs and trains itself without waiting for a further action or instruction from the user. 
       FIGS. 12A and 12B  are diagrams of a chart  1400  that illustrates one set of exemplary embodiments of how the determination of various video tool parameters may correspond to a sequence of point placements, which may be designated “clicks” (e.g., of a button of a mouse, trackball, or other user data entry device). In the chart  1400 , “MC+” stands for multi-click-plus tool operations (e.g., in a multi-click-plus tool mode) and “MC” stands for multi-click tool operations (e.g., in a multi-click tool mode) described further below. Exemplary MC+ operations for a number of video tools have been described above with respect to  FIGS. 3-10 , therefore the rows  1410 ,  1420 ,  1430 ,  1460 , and  1470  are not described in detail, but will be understood based on previous descriptions and general teachings. For purposes of clarification, the entries of row  1410  will be explained. 
     As shown in  FIG. 12A , in row  1410 , the first column indicates that the operations of a multi-click-plus Box tool and/or a multi-click-plus Autotrace tool are summarized in row  1410 . Continuing across row  1410 , column A indicates that when operating the respective video tool GUI&#39;s of the subject tools, the first click establishes the ROI height end point # 1 . Column B indicates that a second click establishes the other end point of the ROI height, end point # 2 , and column C indicates that the second click establishes the ROI angular orientation, as well. Column D indicates that a third click establishes the ROI width (symmetric about the midline), and columns E and F, respectively, indicate that the third click establishes the selector location, and the scan direction, as well. Column G indicates that sampling direction is determined to follow a direction from the location of point # 1 , established by the first click, toward the location of point # 2 , established by the second click 
     The remainder of the rows in  FIGS. 12A and 12B  may be understood based on the preceding explanation. A comparison of each respective row describing “MC tools” with the corresponding “MC+ tool” row above it (corresponding to similar video tools, operated in different modes), shows that the MC tools operate similar to the MC+ tools, with the exception that each of the parameters associated with the operations of columns D, E, F, and G, are set “by default”, that is, the user is only required to perform the clicks indicated in columns A, B and C, in order to completely define the parameters of the MC tools. Accordingly, the MC tool mode has the advantage of offering simpler and more convenient tool operation than the MC+ mode, but it has the disadvantage that the default tool parameters are not customized to a particular feature. Therefore, the MC tool mode may not be suitable for performing inspection operations for some features, for example, some features similar to those shown in  FIGS. 4 and 6 . Nevertheless, in some embodiments, an MC tool may include operating advantages similar to those provided in some embodiments of the MC+ tools. For example, in some embodiments it is advantageous that after a user places a point, one or more parameter indicators may be automatically linked to be dynamically adjusted based on the cursor position (e.g., as the cursor moves away from the point), and that they may be dynamically adjusted based on the cursor position without requiring the user to depress and/or hold down a mouse button after placing the point. 
     While exemplary sequences of operations have been outlined when describing various exemplary embodiments of multi-click-plus video tools with reference to  FIGS. 3-11 , it will be appreciated that in other exemplary embodiments certain operations may be performed in other sequences and/or one or more of the described operating features or GUI features may be omitted, and the other inventive aspects of the methods and GUI&#39;s disclosed herein may still provide substantial benefits. Thus, while the preferred embodiment of the invention has been illustrated and described, it will be appreciated that various changes can be made therein without departing from the spirit and scope of the invention.