Practice Matching Tracks In order to practice with the method we strongly recommend that you install the image processing program ImageJ on your computer. Go to the ImageJ home page, and select Download for the latest version. Once you have successfully installed ImageJ, you can use it to examine the practice images
On each of the introductory practice images you will find a small black square that can be used as an alignment reference between the two images. Move the two images by dragging with the mouse until the squares appear at precisely the same spot on your monitor. Switching between the images will now create the appearance of motion indicating a match. The idea of seeing motion in the two images can be confusing. Try this: Once you have the practice images aligned, pick a single dot somewhere near the alignment mark in the image that happens to be on the screen. Keep looking at the same point on the computer screen as you switch images and use your peripheral vision to note the movement. If this seems difficult at first, be assured this ability can be developed with practice. Eventually one learns to use the motion sensing ability of the peripheral image very efficiently, allowing quick examination of virtually the entire screen image. Easiest - Begin with the pair of images (#1, #2) generated by applying ink to museum specimens. In contrast to a live animal, the lack of pliability of the specimens ensures that virtually all of the dots correspond on these images, making them the easiest to match. A Bit More Challenging - The second set of images (#3, #4), made by applying ink to the feet of a live fisher, are a little more realistic than the museum specimen tracks. Realistic, Wild Fisher Prints - Move on to the marked pair of prints (#5, #6) made on a track plate by a live, free-ranging fisher. Note the print quality is lower than with previous samples and the area of apparent matching is also smaller, although still clearly visible. You're On Your Own - Finally, try to match the remaining pair of images (#7, #8). These were also collected with a track plate that was visited by a free-ranging fisher, but this time there are no alignment marks to guide you. Use the overall outline of the main portion of the metacarpal pad to initially align the two images. This might be easier at a lower level of zoom, perhaps 50%. Align the images and then switch to 100% or more. If no obviously matching areas are noticed with the initial alignment, shift one image a small amount and compare them again. Look for distinctive features that seem to correspond between the images – two or three dots arranged in a particular pattern, unusually large dots, atypical shapes, etc. Consider the possibility that adding some rotation to one image might help with the alignment. The Advanced Matching Practice pages include access to many more images. Advanced Matching Practice
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