There are many ways that images can be acquired in the field and scaled. For instance, if images are taken along a moving conveyer belt, the scaling of the images is straightforward and can be as simple as measuring the width of the belt.

When acquiring images of muck piles, the angle of the slope relative to the axis of the camera needs to be considered. In this case the scale varies continuously from the bottom of the slope to the top of the slope. There are many ways to ensure that muck pile images are scaled correctly.

The most traditional way is to place two objects of known size in the image, one near the bottom of the slope and one near the top of the slope, as shown in Figure 1. Another method is use a rangefinder to determine the distance from the camera to both the bottom and the top of the slope.

The Split-Desktop program has been designed to allow scaling for all of the different image acquisition methods described above. For images where one or two objects are put in the image an interactive scaling tool in the program is used to scale the images as seen in Figure 2. For images where the rangefinder distances are used, the distance to the top and bottom of the slope can be input and the camera needs to be tested for a calibration factor. Contact Split Engineering for information on this method.