Licensing options for this format begin with FME Desktop Professional Edition.
The JPEG 2000 Reader/Writer provides FME with access to data in the JPEG 2000 format.
Overview
JPEG 2000 is a new image coding system that uses state-of-the-art compression techniques based on wavelet technology. JPEG 2000 was designed to overcome the limitations of the original JPEG standard and provide high-quality images at low bit-rates. In addition, JPEG 2000 includes new features and functionalities for client/server imaging applications and resource-constrained wireless devices.
JPEG 2000 has many advantages over JPEG, such as better image quality at the same file size, 25-35% smaller file sizes at comparable image quality, good image quality even at very high compression ratios (over 80:1), low complexity option for devices with limited resources, scalable image files, and progressive rendering and transmission through a layered image file structure.
Coordinate system and georeferencing transformations are read and written via GeoJP21 (GeoTIFF-in-JPEG2000) and GML-in-JPEG2000.
Format Parameters
The JPEG2000 writer supports the following option through the Feature Type dialog:
Compression Level
This option sets the desired compression level of the output image. This is expressed as a percentage of the original file size. For example, setting a compression level of 75 means that the output image will be approximately 75% smaller (one-quarter of the size) than an uncompressed image.
Note that this value only represents the targeted compression level, and this may not actually be achieved. JPEG supports both lossy and lossless compression. With lossy compression, the compressed image is an approximation of the original. With lossless compression, the compressed image is identical to the original.
Note: Repeatedly reading and saving files may decrease the quality for this format. In addition, Workbench may not know which format data comes from, and whether it used lossy compression. If you know that source data comes from files with lossy compression, you should also set the compression level to 0. Although this compression still does not guarantee the exact copy of the source file, the output will be very close to the original.
Reader Overview
FME considers a single JPEG 2000 file to be a dataset. The JPEG 2000 file contains pixel data. Each pixel in the file is a point in a single FME raster feature.
Writer Overview
FME considers a dataset to be a folder name.
FME Raster Features
FME raster features represent raster data and use several concepts that are unlike those used in the handling of vector data. See About FME Rasters.
JPEG2000 files must be written with square pixel dimensions.
JPEG2000 supports rasters with an arbitrary number of bands, provided all bands are the same data type and no band has a palette.