Skip to content

Image display

Capture and analyze images, or perform analysis of previously captured images.

Analysis options

Upon creating a new image display, the following options are visible:

  • Open Image File: Select and open an image saved on your computer.
  • Open and analyze image file: Use analysis tools on an image saved on your computer.
  • Capture Image: Capture a new image using a connected camera.
  • Capture and analyze image: Capture an image using a connected camera, then use the analysis tools on the image.
  • Image Sequence: Display and analyze a sequence of discrete images.

Tools overview

Image capture tools

  1. Analysis Mode

    Click to show or hide the analysis toolbar.

  2. Recording tools

    • Click to begin previewing the selected camera.
    • Click to capture a still image from the camera.
    • Click to exit the image capture mode.

  3. Display tools

    • Click to pin the toolbar to the display.
    • Click to access the display properties.
    • Click to show or hide specific tools from the toolbar.

  4. Displayed image

Analysis tools

  1. Visibility tools

    Use to control the visibility of the image and analysis tools.

    • Click to show or hide the analysis toolbar.
    • Click to create or remove a circle which magnifies the area of the image around the mouse cursor.
    • Click to enable or disable editing of the axes and the measurement and calibration tools.

  2. Markup tools

    • Click to add axes to the image.
    • Click to add a calibration tool the graph.
    • Click to add a distance, angle, or radius measurement tool to the graph.
    • Click to add an editable text box to the graph.

  3. Coordinate tracking tools

    • Click to create a new tracked object.
    • Click to delete the current tracked object.
    • Click the name of the currently selected object to open a dropdown list, where you can select a different object.
    • Click to delete all points in the currently selected object.
    • Click to delete the first point in the currently selected object.

  4. Display tools

    • Click to pin the toolbar to the display.
    • Click to access the display properties.
    • Click to show or hide specific tools from the toolbar.

  5. Calibration tool

    Place over an object of known length in the image and set the length value to calibrate the measurement tool.

  6. Distance measurement tool

    Use to measure the length of an object within the displayed image.

  7. Angle measurement tool

    Use to measure the angle between two lines within the displayed image.

  8. Radius measurement tool

    Use to measure the radius of a circular region of the displayed image.

  9. Axes

    Use with the calibration tool to establish a coordinate system, allowing the coordinates of plotted points to be automatically determined.

Capture images

  1. From the new image display, select Capture Image or Capture and analyze image.
  2. From the Choose Video Camera window, select the desired option from the list of cameras connected to your computer, then click OK.
  3. Ensure your camera is correctly positioned and your desired target is in frame, then click Capture image from the toolbar to capture a still image of the camera view.

If Capture and analyze image was selected, analysis tools will automatically be displayed over the image upon capture. If it was not, you can make the analysis tools visible by clicking Analysis Mode from the toolbar.

Measure objects within images

To measure a length within a captured image:

  1. Set up your camera in the position where it will be for your experiment, then connect it to Capstone.
  2. Create a new image display, then select Capture and analyze image .
  3. Place an object of known length, such as a lined ruler, into the camera's view at approximately the same distance as the object you will be measuring.
  4. Click Capture image from the toolbar to capture an image of the current camera view. The analysis tools will automatically be displayed.
  5. Click the Calibration Tool icon to make the calibration tool appear on the image.
  6. Click and drag the ends of the calibration tool to opposite ends of the object of known length, then click the length measurement on the calibration tool and enter the length of the object in meters.
  7. Click the Analyze Mode button to return to the image capture mode.
  8. Without moving the camera, place the object you wish to measure into view of the camera, then click Capture image again.
  9. Capture an image of the object. The analysis toolbar should automatically reappear on the display.
  10. Click Measurement Tool and select Distance Tool to add a distance measuring tool to the graph.
  11. Click and drag the tips of the distance measuring tool to the edges of the length you want to measure. The length of the tool, and by extension the length it corresponds to within the image, will automatically be displayed next to the tool at all times.

The other two options in the Measurement Tool menu, Angle Tool and Radius Tool, can be added in the same way.

Find coordinates of points in an image

The image display features a system for creating a set of coordinate axes and plotting points on an image. The coordinates and other values associated with these points can then be displayed and analyzed in a separate display. To track the coordinates of points in an image:

  1. Capture an image of the points you wish to track, then enter Analysis Mode for the image. Ensure there is an object or marking of known length visible within the image.
  2. From the analysis toolbar, select Create Tracked Object . Upon doing so, your mouse cursor should turn into a symbol resembling a plus sign.

  3. Click on each of the points you wish to track. A plus-shaped marker should appear at each clicked point.

    Note

    If you wish to restart the point collection process, you may select Delete all points to remove all points from the selected object.

  4. Click the Calibration Tool icon to make the calibration tool appear on the image.

  5. Click and drag the ends of the calibration tool to opposite ends of the object or marking of known length in the image. Click the length measurement on the calibration tool and enter the length of the object in meters.
  6. Click the Axes icon to add a pair of coordinate axes to the graph. The origin of these axes on the image will correspond to the zero value of the x-coordinates and y-coordinates, and the orientation of the axes will determine the positive x and y directions. Click and drag the axes to an appropriate position and orientation.

When the axes, the calibration tool, and a tracked object are all added to the image, five new sets of user-entered data will automatically be created. These sets correspond to the position of each data point in the tracked object and can be plotted in another display, such as a graph display or table display. The data sets created are:

  • x-Position: Each value measures the horizontal coordinate of the corresponding point, relative to the specified origin.
  • y-Position: Each value measures the vertical coordinate of the corresponding point, relative to the specified origin.
  • Radius: Each value measures the radius of a circle centered at the origin and passing through the corresponding point.
  • Angle: Each value measures the angle between the x-axis and a line from the origin to the corresponding point.
  • Arc Length: Each value measures the arc length, on a circle centered at the origin and passing through the corresponding point, between the x-axis and the point.