Many of the CoastWatch products are availabe in GeoTIFF format. TIFF (Tag Image File Format) images are a commonly used graphics
format compatible with many different types of software. TIFF images are composed of a grid of pixels, which are each defined by a
number representing a color or shade of gray. The actual color that each value represents is defined by a colormap associated with the
image. GeoTIFF images are an extended form of TIFF image that contain georeferencing information that allow programs like
ArcView to correctly scale and place them on a map.
GeoTIFF images are small and can be displayed directly in many Geographic Information System (GIS) applications.
They are widely compatible with common graphics software since the image data follows the widely supported TIFF specifications.
GeoTIFFs combine image and georeferencing information into a single file, unlike some other georeferenced formats that require a separate
header file.
The GeoTIFF images available from CoastWatch are 8-bit images, meaning that the number associated with each pixel is represented by a
binary code of eight characters, for example, 01100101. Because there are only 256 combinations of zeros and ones that can be represented
in eight bits, the pixel values of an 8-bit TIFF image are limited to integer numbers from 0 to 255. For this reason, data that contain
decimals, negative numbers, or values greater than 255 can not be represented directly in the GeoTIFF format.
CoastWatch GeoTIFFs are single image plane, palette-color, 8-bit images that use PackBit compression.
