PRF or MegaTIFF is an internal format of PHOTOMOD software for storing large images.
This format was developed to store images larger than 4 GB. As a basis for storing data used TIFF or JPEG2000 format. Raster is split into fragments (tiles) such that each fragment does not exceeded a predefined size (e.g., less than 1 GB). An overview file also added to process raster data on a small scales.
PRF files has two variations: 'prf' for imagery data and 'x-dem' for elevation data. Files can be georeferenced, but projection information can be stored only in external files (*.prj).
Image format has the following structure:
The driver support the data type among Byte, UInt16, UInt32, Float32 or Float64.