Calibration

When the image has been imported, the first step is to calibrate the measurements. This action basically sets the scale that all future measurements on the image in question are based on.

Practically, this is done by measuring a known length, normally a ruler. The ruler is often used, because it is a direct and simple way of showing the scale of the image, both when calibrating our software and for visual reference for the user.

Other objects can be used, however. Any object where a dimension is known is usable.

Note: When acquiring the image, make sure that the ruler are in the same depths or level as the wound, and that the ruler does not cover parts of the wound. As an example, if the ruler is placed on the table and the wound is on the arm, the difference in depths relative between the two, will make the measurements less accurate. The closer the ruler is placed to the wound, the more accurate the result will be.

Manual calibration

After an image has been acquired, the (Calibrate) tool is automatically selected.

Before calibrating, choose the desired unit and how many units you are calibrating with. Basically, calibrating is adjusting the scale of the image. This is done by measuring a known length on an object, to use as a reference for all future measurements in the individual image. This is often a ruler. Choose the desired amount and unit, thereafter measure the object. Left-click once where you want to start the calibration, double-left-click where you want to end the calibration. When this is done, the measuring tools are available.

Fixed calibration

Fixed calibration is done the same way as described under manual calibration. The difference is that the calibration is fixed and automatically used for all future measurements within the workspace, object, course or the entire application. When choosing fixed calibration in the Settings menu, choose whether you want it to be for the course, object, workspace or whole application. This means that the current calibration on the selected image is used for future images.

Automatic calibration

This feature automatically recognizes a distinct square shape, and uses the diagonal as the calibrated length. This is used if the same ruler (or any other square with a known length) is used every time. Type in the default calibration value, and choose Automatic Calibration. When an image is acquired, the image will be calibrated and ready to be measured. This requires Automatic calibration to be applied, and a square shape to be present in the image.

The option for automatic calibration, allows for the software to automatically detect rectangle and add a user-defined length of the diagonal. On the left is shown an example of how the automatically detected ruler could look like.

Most important is an easily detected color, and that the rectangle has a known diagonal length. The diagonal length is shown with the dashed line marked with a d above.

When the option for automatic calibration is chosen, all future images will be calibrated detecting the ruler and applying the given diagonal.