Pixelink Capture now supports basic measurement functionality. This allows you to make simple measurements of the camera's image from within the application. The application currently supports the following measurement tools (Point, Line, Circle, Rectangle, PolyLine, Polygon and Angle). Measurements that are made can then be exported to an Excel spreadsheet.
Measurement Workflow:
In order to use the Pixelink Capture Metrology functionality, the following workflow should be followed:
1) Create a spatial calibration that associates camera pixels with real life measurements
2) Making measurements
3) Reviewing and adjusting measurements
4) Exporting Measurements to an Excel Spreadsheet
Spatial Calibration:
Before any measurements can be made the Measurement tool must be calibrated. Measurements are made based on the relative location of camera pixels. Calibrating the tool allows measurements to be displayed in real world units (i.e. millimetres, microns, inches, mils, etc). To create a new calibration click the "new" button. A calibration line will appear in the preview window (see image below). Drag and reposition the calibration line to cover the span of a known distance in the preview window. To resize the calibration click and drag the ends of the line. To move the line, click and drag on the middle. In this example the ticks on a ruler are used as the known distance (from 1 cm to 2 cm). Commonly used objects of a known distance are rulers (as in this example), components of a known and standard size (such as a 1.5 mm wide resistor) or a custom printed pattern of a known size.
Once the calibration line is in position, enter a name, select the desired unit for this calibration, and specify the number of units that the calibration line represents. In this example we will name the calibration "Cal One", the units are in millimeters, and there are 10 units in the calibration line. Once the number of units in the calibration line are entered the application will automatically calculate the relationship between camera pixels and the selected unit. In this example every millimeter is equivalent to 42.142 pixels.
Click "Save" to finish the calibration. Calibrations are saved between sessions of Pixelink Capture. They can also be edited or deleted at any time by clicking on the "Edit" or "Delete" buttons. Saved calibrations are selectable in the dropdown menu. Calibrations can be saved to and imported from an XML files by using the "Export" and "Import" buttons respectively.
Making Measurements:
To make a measurement click on the desired measurement tool. The available measurement tools are point, line, circle, rectangle, polyline and polygon. Once the measurement is made the tool can be deselected by clicking on the active tool's button again. Measurements that have been made can be adjusted (for example, repositioning a point or changing the radius of a circle). Measurments can only be adjusted while all of the measurement tools are not active.
Point - The point tool creates a crosshair over a single pixel and will display the pixel's X and Y coordinates. To create a point click on the preview window where you would like to create the point. To reposition a point move the cursor over the crosshair, click down the mouse, drag the point to a new location, then release the mouse.
Line - The line tool draws a line between two pixels and displays the distance between them. To create a line, click down at a position on the preview window to start the line, drag the mouse to the desired end position, and release the mouse. To move the line, click down on it and move it to the desired position. To resize the line, click and drag the line's start or end points.
Circle Radius - The circle tool creates a circle measurement by creating a line representing the circle's radius. The start point of the line is the final circle's origin. The circle can be adjusted by clicking down and dragging the radius line's start and end points.
Circle (Diameter) - The circle tool creates a circle measurement by creating a line representing the circle's diameter. The circle can be adjusted by clicking down and dragging the diameter line's start and end points.
Circle (Perimeter) - The circle tool creates a circle measurement by creating a triangle with each vertex of the triangle laying in the desired circle's perimeter. The circle can be adjusted by clicking down and dragging vertices of the triangle.
Rectangle - The rectangle tool creates a rectangle and displays the rectangle's area. To create a rectangle, click down and drag the mouse. The start and stop positions of the drag will be opposite corners of the rectangle. To adjust the size of the rectangle click and drag any of the rectangle's corners.
Polyline - The polyline tool allows you to create a series of line segments and will display the total length of all of the segments. To create a polyline click a series of points in the preview window. Lines will be drawn between each point. To finish making the polyline, click the right mouse button. Polylines can be adjusted by clicking and dragging the vertices.
Polygon - The polygon tool allows you to create a polygon of any number of sides and will display the total enclosed area of the measurement. To create a polygon click a series of points in the preview window. Lines will be drawn between each point. To finish making the polygon click the right mouse button. Polygons can be adjusted by clicking and dragging the vertices.
Angle - To create a angle measurement click a series of three points in the preview window. Lines will be drawn between the first and second point as well as the second and third point. The tool will then measure the angle between the two lines. The angle measurement can be adjusted by clicking and dragging the three points.
Auto Angle - To create a angle measurement open the Auto Find Angle drop down, click the "Auto Find Edges" button, select the two lines that you would like to measure the angle between (selected angles will be highlighted orange), then click "Calculate Angle". Adjust the maximum edge tolerance slider to a high value to show a larger number of potential edges. Adjust the maximum edge tolerance slider to a low value to show a smaller number of potential edges.
Auto Circle - To create a auto circle measurement open the Auto Find Circles drop down, click the "Auto Find Circles" button, select the circles that you would like to measure (selected circles will be highlighted orange), then click "Measure Circles". Adjust the maximum circle tolerance slider to a high value to show a larger number of potential circles. Adjust the maximum edge tolerance slider to a low value to show a smaller number of potential circles.
Options:
Pixelink Capture gives you the ability to customise the look of the measurements you make. You are able to customise the draw, highlight and text colour of your measurements. You can also choose to show or hide the measurements' value text by clicking the "Show Values in Preview" check box.
Measurement Review:
The active measurements box allows you to review, rename and delete measurements. To rename a measurement right click it and then click "Rename". To delete a measurement right click it and click "Delete". To delete all measurements click the "Delete All" button.
Export:
Once you are satisfied with your measurements you can export them to an Excel spreadsheet by clicking the "Export to Excel" button. The exported spread sheet will display all measurements, as well as their relevant measurement values and a screen shot of the preview window.
