Glossary#

A collection of common terms used in torchgeo that may be unfamiliar to either:

Deep learning researchers who don’t know remote sensing
Remote sensing researchers who don’t know deep learning

area of interest (AOI)#: Synonym for region of interest (ROI). A particular spatial area to focus on.
chip#: Synonym for patch. A smaller image sampled from a larger tile.
classification#: A computer vision task that involves predicting the image class for an entire image or a specific bounding box.
coordinate reference system (CRS)#: Synonym for spatial reference system (SRS). A system that defines how to locate geographic entities on a projected surface.
index#: The lookup table of a geospatial dataset (GeoDataset.index): a mapping from each file’s spatiotemporal footprint to its path, used to find which files a query overlaps. It is metadata, not pixel data. Unrelated to a spectral index; and note that the index argument of __getitem__ is, despite its name, a query.
instance segmentation#: A computer vision task that involves predicting labels for each pixel in an image such that each object has a unique label.
object detection#: A computer vision task that involves predicting bounding boxes around each object in an image.
patch#: Synonym for chip. A smaller image sampled from a larger tile.
projection#: A geometric transformation for portraying the surface of a 3D Earth onto a 2D planar image.
query#: The spatiotemporal bounding box passed to a geospatial dataset’s __getitem__ (a GeoSlice), describing where and when to sample. Distinct from the dataset’s index, which is how files are found. When a query is read in a file’s native coordinate reference system (CRS), its box may align to a different grid than the index.
region of interest (ROI)#: Synonym for area of interest (AOI). A particular spatial region to focus on.
regression#: A computer vision task that involves predicting a real valued number based on an image.
semantic segmentation#: A computer vision task that involves predicting labels for each pixel in an image such that each class has a unique label.
spatial reference system (SRS)#: Synonym for coordinate reference system (CRS). A system that defines how to locate geographic entities on a projected surface.
spectral index#: A per-pixel combination of spectral bands that highlights a phenomenon, such as NDVI (vegetation) or NDBI (built-up area). Unrelated to a dataset’s index.
stitching#: Combining a collection of patches into a single image. This is the reverse operation of tiling.
swath#: A set of tiles along a satellite trajectory.
tile#: A single image file taken by a remote sensor like a satellite.
tiling#: Splitting a tile into patches. This is the reverse operation of stitching.