HR: 0800h
AN: P31B-0437    [Abstracts]
TI: Image Differencing for Detecting Surface Changes on Mars
AU: * Coveney, E W
EM: coveney@gmail.com
AF: Fort Hays State University, 600 Park Street, Hays, KS 67601, United States
AU: Heinrichs, J F
EM: jheinric@fhsu.edu
AF: Fort Hays State University, 600 Park Street, Hays, KS 67601, United States
AB: Visual observation methods to compare images for detecting Martian surface changes have been effective and efficient for images with different spatial resolutions and varying temporal windows. Large data streams from the Mars Reconnaissance Orbiter and future missions require automated detection techniques to detect changes that might reveal surficial processes. This study investigates the use of image differencing techniques to assist with identifying new slope streaks on the Martian surface. Two separate differencing methods were used to generate difference maps - a simple difference method, in which the initial state pixel values are subtracted from the final state pixel values, and a percentage difference method, in which a simple difference pixel value is divided by the initial state pixel value. Difference maps were normalized by subtracting the minimum pixel value and dividing by the range of pixel values across the image. The difference maps were then overlaid over the original image to emphasize new slope streaks. The simple pixel differencing results improved when 11 equal classification thresholds between -1 and +1 were defined, however the percentage differencing technique yielded a difference map that better emphasized slope streaks. The image differencing technique showed other changes in the computed difference maps, though these differences may be attributed to changes in lighting conditions, perspective, or image calibration.
DE: 5464 Remote sensing
DE: 5470 Surface materials and properties
DE: 5494 Instruments and techniques
SC: Planetary Sciences [P]
MN: 2007 Fall Meeting