Image Matching Game

Scaling Up Marsh Science

Useful Tips




Artificial Objects

Plant Roots

Foot Prints

1. The photographs were taken using a camera mounted between two bicycles. You will see the bicycle tire or the shadow of the mounting apparatus in some photographs. Because these move with the camera, they are not useful landmarks for matching.

2. The images overlap vertically by about 20 percent. Useful landmarks for matching will typically be found near the top of one image and near the bottom of the paired image. In some cases, however, we were moving more slowly, and the images overlap considerably.

3. The best landmarks to use in matching the images are snails, mussels, crab burrows, or unique features of the vegetation that are close to the ground (for example, a plant stem where it comes out of the ground, or a leaf lying on the ground). Leaves up high in the vegetation are the worst features, because they move with the wind and their location is affected by the camera angle. But in photographs with dense vegetation, these may be the only options.

4. In some cases, you'll find images that don’t match. For example, we may have been turning the camera around to take another row of photographs. In these cases, click on the button "Images don't overlap".

5. In other cases, the images are so full of detail that it is hard to identify good landmarks for matching them up. If a particular pair of images is too hard to match, click on the button "Show next pair" and you'll get another pair of images to try. Don't be afraid to skip pairs of images repeatedly. It is better to skip them than to give us inaccurate data. As you gain in experience, you'll be able to handle more and more challenging pairs of images.