Mathematica Import/Export Format

JPEG2000 (.jp2, .j2k)

MIME type: image/jp2
JPEG2000 raster image and compression format.
Used for photographic images.
JPEG is an acronym for Joint Photographic Experts Group.
Binary file format.
Supports a variety of color resolutions and opacity.
Uses lossy or lossless compression based on wavelet transforms.
Can store images as an array of rectangular tiles that are encoded separately.

Import and Export support the JP2 file format as well as the JPEG2000 features specified in Part 1 of the ISO 15444 standard.

IMPORT AND EXPORT

Import["file.jp2"] imports a JPEG2000 file, returning a graphics object.

Export["file.jp2", expr] exports graphics or any other expression as an image to a JPEG2000 file.

Import["file.jp2"] returns an expression of the form Graphics[Raster[data], opts], where data is an array of color values.

Export["file.jp2", expr] creates a JPEG2000 image with the same image size as the displayed form of .

Because JPEG2000 is a raster image format, all fonts are rasterized on export.

Import["file.jp2", elem] imports the specified element from a JPEG2000 file.

Import["file.jp2", {elem, sub_a, sub_b, ...}] imports a subelement.

Import["file.jp2", {{elem₁, elem₂, ...}}] imports multiple elements.

The import format can be specified with Import["file", "JPEG2000"] or Import["file", {"JPEG2000", elem, ...}].

Export["file.jp2", expr, elem] creates a JPEG2000 file by treating expr as specifying element elem.

Export["file.jp2", {expr₁, expr₂, ...}, {{elem₁, elem₂, ...}}] treats each expr_i as specifying the corresponding elem_i.

Export["file.jp2", expr, opt₁->val₁, ...] exports expr with the specified option elements taken to have the specified values.

Export["file.jp2", {elem₁->expr₁, elem₂->expr₂, ...}, "Rules"] uses rules to specify the elements to be exported.

See the reference pages for full general information on Import and Export.

ImportString and ExportString support the JPEG2000 format.

NOTEBOOK INTERFACE

In the notebook front end, Insert ► Picture and the Open menu allow import of a JPEG2000 file into a cell.

Save Selection As exports the selected part of a notebook as a JPEG2000 file.

ELEMENTS

General Import elements:

	"Elements"	list of elements and options available in this file
	"Rules"	full list of rules for each element and option
	"Options"	list of rules for options, properties, and settings

Data representation elements:

	"Data"	array of color values
	"Graphics"	raster image given as a Graphics object
	"GrayLevels"	array of normalized gray-level values
	"RGBColorArray"	array of RGBColor objects

Import and Export by default use "Graphics" for JPEG2000 files.

Import["file.jp2", "Data"] gives an array of color values taken to be encoded using the color model specified by the "ColorSpace" option.

Advanced Import elements:

	"BitDepth"	bit resolution used for each color channel in the file
	"ImageSize"	raster dimensions

OPTIONS

General option:

ImageSize

Automatic

overall image size

Import and Export option:

"ImageTopOrientation"

Top

orientation of the image as stored in the file

Export options:

"BitDepth"	8	bit resolution used for each color channel
"CompressionLevel"	Automatic	sets the compression parameter of the image-encoding algorithm
"ImageTopOrientation"	Top	orientation of the exported image

Allowed settings for "BitDepth" are integers in the range 1 to 31.

Possible values of "CompressionLevel" range from 0 to 1, with larger values corresponding to smaller file sizes.

For lossy compression methods, a higher compression level corresponds to a lower quality encoding.

Detailed properties and settings:

	"ColorSpace"	Automatic	color space of the image
	"ImageEncoding"	"JPEG2000"	compression method used in the file

Import and Export support JPEG2000 alpha channels in gray-level and RGB images.

Possible settings for "ImageEncoding":

	"JPEG2000"	standard lossy JPEG2000 encoding
	"Lossless"	lossless variant of the JPEG2000 compression method