Dynamic Landmarking


This page contains some example results of automated landmark detection and change detection.

Landmark Detection

The following two images were taken two years apart on Mars. They were analyzed independently to identify landmarks (visually salient regions) without human intervention. The selected landmarks, which are outlined in red, include dark slope streaks, ridges, and steep slopes.

To obtain these results, the salience threshold was automatically (and independently) selected given the distribution of salience across each image.

Landmarks in MOC image M16-00596, June 12, 2000 Landmarks in MOC image E15-00356, April 12, 2002
MOC M16-00596, June 12, 2000 MOC E15-00356, April 12, 2002

Landmark-based Change Detection

These change detection results were obtained when comparing manually annotated landmarks (here, just the dark slope streaks) in the two images. Additional constraints are needed when working with the automatically detected landmarks. Stay tuned for those results!

All landmarks are correctly matched between the two original images, and the two new dark slope streaks are correctly identified (marked in red). Click for a larger version.

Matched landmarks between M16-00596 and E15-00356, with two new
landmarks correctly detected
MOC M16-00596, June 12, 2000 MOC E15-00356, April 12, 2002

Pixel-based Change Detection

In these results, we registered the two original source images together at the pixel level, then subtracted the new one from the old one. The result is a difference map that shows changes on a per-pixel basis. Here, blue indicates areas that got darker in the second image, while yellow indicates areas of brightening.

Home Plate: Spirit's journey. Spot the rover and its tracks!
HiRISE PSP_001513 (11/22/06) HiRISE PSP_009174 (7/11/08) Difference

El Dorado dune field: new dust devil tracks and mysterious bright->dark spots
HiRISE PSP_003900 (5/27/07) HiRISE PSP_010097 (9/21/08) Difference
Morphing video (AVI)

Nicholson Crater: new dark slope streaks
THEMIS V01853007 (5/16/02) THEMIS V17467028 (11/22/06) Difference
Morphing video (AVI)