Glossary
This page defines common geospatial and technical terms used throughout the Habitat-Mapper documentation.
Geospatial Terms
- Band
- A layer of data in an image representing a specific wavelength of light captured by a sensor. For example, separate bands for Red, Green, Blue, and Near-Infrared (NIR) light. Multi-band images allow analysis beyond what the human eye can see.
- Coordinate Reference System (CRS)
- The geographic framework that defines where on Earth an image is located. Also called a "coordinate system" or "projection". Common examples include WGS84 (used by GPS) and UTM zones.
- GeoTIFF
- An image file format (
.tif) that includes embedded geographic information such as coordinates, projection, and pixel size. This allows GIS software to automatically place the image in the correct location on a map. - NIR (Near-Infrared)
- Light with wavelengths just beyond what humans can see (roughly 700-1400 nanometers). Many sensors capture NIR because it's useful for detecting vegetation health and water content. Healthy plants strongly reflect NIR light.
- Nodata Value
- A special pixel value in a raster that indicates "no information here". For example, black areas outside the survey boundary in a drone orthomosaic are often marked with a nodata value of
0so software knows to skip them. - Orthomosaic
- A geometrically corrected aerial image created by stitching together many overlapping drone or aircraft photos. Distortions from camera angles and terrain are removed, making it suitable for accurate measurements.
- Pixel Resolution
- The ground distance represented by one pixel in an image, often expressed in centimeters or meters. For example, "5cm resolution" means each pixel covers a 5cm × 5cm area on the ground. Smaller values mean higher detail.
- Raster
- An image or grid where data is stored as a matrix of pixels (cells). Each pixel has a value representing something like color, elevation, or classification. Satellite images and drone photos are rasters.
- Segmentation
- The process of classifying each pixel in an image into different categories (e.g., kelp, water, rock). Habitat-Mapper performs segmentation to identify where species are present.
- Tiled GeoTIFF
- A GeoTIFF organized internally into small square chunks (tiles) rather than as continuous rows. This structure dramatically speeds up reading small portions of large images, which is essential for Habitat-Mapper's sliding window approach.
Technical Terms
- Batch Size
- The number of image tiles processed simultaneously by the model. Larger batch sizes can improve speed if you have sufficient GPU memory, but may cause crashes if set too high.
- CLI (Command Line Interface)
- A text-based way to interact with software by typing commands into a terminal, rather than clicking buttons in a graphical interface. The
habcommand is Habitat-Mapper's CLI. - Crop Size / Tile Size
- The dimensions (in pixels) of the square windows Habitat-Mapper uses to process large images. Larger crop sizes reduce stitching artifacts but require more memory. Must be an even number (e.g., 1024, 2048, 3200).
- Inference
- The process of applying a trained machine learning model to new data to make predictions. When you run
hab segment, you're performing inference on your imagery. - Model
- A trained deep learning algorithm that has learned to recognize patterns in imagery. Habitat-Mapper includes multiple models for different sensors and species (e.g.,
kelp-rgb,mussel-gooseneck-rgb). - ONNX
- Open Neural Network Exchange, a standard format for saving machine learning models. Habitat-Mapper uses ONNX models so they can run efficiently on different hardware without needing specific deep learning frameworks.
- Virtual Environment
- An isolated Python installation that keeps Habitat-Mapper's dependencies separate from other software on your computer. This prevents version conflicts and makes installation cleaner.
- uint8 / uint16
- Data types for storing pixel values as unsigned integers.
uint8uses values 0-255 (8 bits), whileuint16uses 0-65535 (16 bits). Habitat-Mapper expects input images in one of these formats.
Related Resources
- Input Requirements - Technical specifications for imagery
- Terminal Crash Course - Introduction to command line basics
- FAQs - Answers to common questions