Digital image comparison by subtracting contextual transformations—percentile rank order differentiation

Photogrammetric Engineering and Remote Sensing


  • The Publications Warehouse does not have links to digital versions of this publication at this time
  • Download citation as: RIS | Dublin Core


The common method of digital image comparison by subtraction imposes various constraints on the image contents. Precise registration of images is required to assure proper evaluation of surface locations. The attribute being measured and the calibration and scaling of the sensor are also important to the validity and interpretability of the subtraction result. Influences of sensor gains and offsets complicate the subtraction process. The presence of any uniform systematic transformation component in one of two images to be compared distorts the subtraction results and requires analyst intervention to interpret or remove it. A new technique has been developed to overcome these constraints. Images to be compared are first transformed using the cumulative relative frequency as a transfer function. The transformed images represent the contextual relationship of each surface location with respect to all others within the image. The process of differentiating between the transformed images results in a percentile rank ordered difference. This process produces consistent terrain-change information even when the above requirements necessary for subtraction are relaxed. This technique may be valuable to an appropriately designed hierarchical terrain-monitoring methodology because it does not require human participation in the process.

Publication type Article
Publication Subtype Journal Article
Title Digital image comparison by subtracting contextual transformations—percentile rank order differentiation
Series title Photogrammetric Engineering and Remote Sensing
Volume 61
Issue 10
Year Published 1995
Language English
Publisher American Society for Photogrammetry and Remote Sensing
Contributing office(s) Earth Resources Observation and Science (EROS) Center
Description 6 p.
First page 1273
Last page 1278
Google Analytic Metrics Metrics page
Additional publication details