- crisp
- binary yes/no pixel assignment,
- fuzzy - probability-per-class pixel assignment,
- hybrid
- combination using ancillary data,
- cart - classification and
regression tree
analysis.
Object Based Classification -
We segment the
imagery into homologous vector polygon "objects" by using: scale,
color, texture parameters and apply hierarchical rules for per pixel
classification.
Pixel Based Classification - We use spectral clustering / ISODATA (Iterative Self Organizing Data Analysis Technique)
to implement various statistically based classifiers that consider each
pixel's multi-layer value without consideration of its neighbors.
Innovative classifier supervision is possible.
Classification Accuracy Assessment - Accuracy specifications cited in our
proposals are meant to endure rigorous comparisons to independent
accuracy assessment surveys reporting omission
and commission error on a per-theme and overall basis.
Raster to Vector Feature Extraction
- We
offer geometrically smooth lightweight accurate thematic data in topologically clean "line" and "polygon" formats from the following
data sources.
-
Multi-spectral and Panchromatic Imagery
-
Lidar Data
-
Paper Maps
Land Cover / Land Use (LC/LU)
Change Analysis
Imagery based
thematic change detection
analysis provides methodological versatility when updating LC/LU layers.
A good change analysis product is augmented with a
thematic "from-to" category layer and various statistics. We
are experienced with these general methods ...
-
multi-temporal
compositing - offers quick and potentially effective results. It requires
cloud-free imagery collected on near-anniversary dates by similar sensor models.
-
cross correlation - offers
more flexibility with source data requirements by allowing the initial ("from")
image data to be thematically classified.
-
post classification - offers the most flexibility
by accepting thematically classified ("from") and ("to")
input imagery. It can be
effectively used to mitigate extreme variation between ("from") and ("to")
environmental conditions.
