# Presentation: 438702

## JPEG 2000:A PDS Perspective

- Elizabeth Rye
- May 23, 2005

## Archive Format Considerations

- Data Providers
- Cost
- Current Users
- Ease of use
- Data Integrity
- Future Users
- Data Integrity
- Data Accessibility

**Notes:**
Data providers 
	- cost 
		- data production
		- data storage volume
		- data validation
Current users
	- ease of use
		- display software
		- internet transfer times
	- data integrity
		- data loss due to compression
		- color accuracy
		- data errors during transfer

Future Users
	data integrity
		- data loss due to media decay
	- data accessibility
		- data extraction if  format obsolete

## Not just an improved version of JPEG...

- Compression scheme
- JP2 image format

**Notes:**
Compression scheme 
	- raw codestream

Jp2 file format 
	- metadata not explicitly required for decoding the codestream

## The Compression Scheme

- Based heavily on EBCOT (Embedded Block Coding with Optimized Truncation)
- Higher compression ratio than JPEG
- Lossless compression available
- Improved error resilience
- Region of Interest (ROI)

**Notes:**
The basic idea in EBCOT is to divide each subband into blocks of samples which are coded independently. For each block, a separate bitstream is generated without using any information from the other  blocks. The bit stream has the property that it can be truncated to a variety of discrete lengths. 

Once the entire image has been compressed, a postprocessing  operation passes over all the compressed blocks and determines  the extent to which each block's embedded bit stream should be  truncated in order to achieve a particular target bit rate,  distortion bound or other quality metric. More generally, the final  bit stream is composed from a collection of so-called "layers",  where each layer has an interpretation in terms of overall image  quality. 

## The Compression Scheme

- Browsing
- Subsetting
- Zooming
- Panning

- Enables:

**Notes:**
Browsing
	- can be decoded with different output resolution or precision
Subsetting
	- stored as tiles; can be retrieved as such

## JP2 - the format

- binary container
- image properties
- intellectual property rights information
- metadata (including vendor-specific information)

- From the specification:

**Notes:**
From the specification:
	- binary container for both image and metadata
	- mechanism to indicate image properties, such as the tonescale or colourspace of the image
	- mechanism by which readers may recognize the existence of intellectual property rights information
	- mechanism by which metadata (including vendor-specific information) can be included

## Metadata storage

- XML-based
- Could collaboratively incorporate work of other organizations in the field: ASU, MIPL, USGS

## Documentation

- Formal specification only available through ISO/IEC
- Final draft available online
- Evolving standard?

**Notes:**
Formal specification only available through ISO/IEC
	- Part 1 costs 234,00 CHF (~US$190) for single user license
Final draft available online
	- missing several parts present in formal spec
Evolving standard?
	 “This second edition cancels and replaces the first edition (ISO/IEC 15444-1:2000), of which it constitutes a minor revision.  It also incorporates the Amendment ISO/IEC 15444-1:2000/Amd.1:2002 and the Technical Corrigenda ISO/IEC 15444-1:2000/Cor.1:2002 and ISO/IEC 15444-1:2000/Cor.2:2002.”

Last “official” version of Java reference software  (v4.1) is not consistent with current standard; v5.1 is not official, nor is it clear if it is supported (see part V of spec.)
(will backwards compatibility be maintained?)

## Part I: Core coding system (royalty and license free; NOT patent free)
Part II:  optional extensions for performance improvement
Part III: Motion JPEG 2000 
Part IV: Conformance (validation tests)
Part V: Reference software (Java and C)
Part VI: Compound image file format (fax, electronic publishing, etc.)
Part VII: abandoned. 
Part VIII: JPSEC (security aspects)   
Part IX: JPIP (interactive protocols and API)    
Part X: JP3D (volumetric imaging)
Part XI: JPWL (wireless applications)
Part XII: ISO Base Media File Format (common with MPEG-4)

- Part II:  optional extensions for performance improvement
- Part III: Motion JPEG 2000
- Part IV: Conformance (validation tests)
- Part V: Reference software (Java and C)
- Part VI: Compound image file format (fax, electronic publishing, etc.)
- Part VII: abandoned.
- Part VIII: JPSEC (security aspects)
- Part IX: JPIP (interactive protocols and API)
- Part X: JP3D (volumetric imaging)
- Part XI: JPWL (wireless applications)
- Part XII: ISO Base Media File Format (common with MPEG-4)

- The Specification

## Software

- Open-source, software-based, free implementations of the codec:
- JasPer (C) version 1.700.2 or later
- _[http://www.ece.uvic.ca/~mdadams/jasper/](http://www.ece.uvic.ca/~mdadams/jasper/)_
- JJ2000 (Java) version 5.1 or later
- _[http://JPEG 2000.epfl.ch/](http://jpeg2000.epfl.ch/)_

## Patent & Copyright Issues

- “The ISO and the IEC draw attention to the fact that it is claimed that compliance with this Recommendation may involve the use of patents...”
- “ISO and IEC take no position concerning the evidence, validity and scope of these patent rights.
- The holders of these patent rights have assured the ISO and IEC that they are willing to negotiate licences under reasonable and non-discriminatory terms and conditions with applicants throughout the world...
- Attention is drawn to the possibility that some of the elements of this Recommendation may be the subject of patent rights other than those identified above.  ISO and IEC shall not be held responsible for identifying any or all such patent rights.”

## Patent & Copyright Issues, Cont.

**Question: Where are the JPEG 2000 test images? The paper "JPEG 2000 still image coding versus other standards" refers to an official JPEG 2000 test set, is it generally available? **
- Answer:  The images consisted of quite a large set, some of which were donated just for the purposes of the evaluation. Unfortunately, many of these have associated copyright that prevent us making them widely available.  We do plan to review this shortly, and we plan to make some images available, once we have the necessary agreements A few images were from standard test charts, and could be purchased with the test chart.  If there is sufficient interest, we can start a section on test images

- From official JPEG web site - “http://www.jpeg.org/faq.phtml?action=show_answer&question_id=q401cd0c215e50”

## Implementation

- Compression only:
- PDS attached label contains all metadata
- .IMQ extension

- Full JP2 format:
- PDS detached label
- Metadata also contained in JP2 label
- .JP2 extension

- Assuming compression algorithm to be applied to tiled raster image:

## Requirements

- Compression only:
- Images validated for compliance
- Decoding algorithm included in archive
- Current version of specification must be maintained

- Full JP2 format:
- Same as for compression scheme
- Include documentation on vendor-specific metadata in archive

## Impact (Archive Considerations Only)

- Compression only:
- Implement decoding algorithm in NASAView

- Full JP2 format:
- Implement decoding algorithm in NASAView
- Metadata repeated in two places, possibly with differing keywords

## Summary - Archive Format Considerations, Revisited

- Data Providers
- Cost
- Current Users
- Ease of use
- Data Integrity
- Future Users
- Data Integrity
- Data Accessibility

**Notes:**
Data providers 
	- cost 
		- data production
		- data storage volume
		- data validation
Current users
	- ease of use
		- display software
		- internet transfer times
	- data integrity
		- data loss due to compression
		- color accuracy
		- data errors during transfer

Future Users
	data integrity
		- data loss due to media decay
	- data accessibility
		- data extraction if  format obsolete