Advanced Imaging

Advanced Imaging > ArchivePack

ArchivePack

A Comprehensive Suite of Software Tools to Build
Client/Server Image Viewing Applications

Aware’s ArchivePack provides all of the software tools necessary to richly featured digital image viewing applications that are easy to implement and use. It leverages the benefits of JPEG 2000 compression software (Why JPEG 2000 for digital archives?) while maintaining the ability to view images from a client with an ordinary browser and no plug-ins or special software.

ArchivePack includes:

• Aware JPEG 2000 Image Server Toolkit
• Aware JPEG 2000 SDK for image compression, decompression, and formatting
• Aware Batch Processor, including example programs and scripts with source code 
• Aware JPX SDK to add and remove metadata throughout the JPEG 2000 standard metadata structure
• Aware Metadata Editor, a Windows UI tool that provides a desktop JP2/JPX metadata editing capability

JPEG 2000 Image Server Toolkit

Aware’s JPEG 2000 Image Server software is a light Java Server application designed to provide efficient access to JPEG 2000 encoded image files in a client/server environment. Designed for use by software developers and systems integrators, the Aware JPEG 2000 Image Server enables the development of client/server image viewing applications that leverage the scalability and features of the JPEG 2000 standard.

The core technology of the Aware Image Server is the Aware J2K Codestream Reformatter, which enables client-selected regions and resolutions of an image to be extracted and transcoded prior to transmission. 

By working with compressed data on the server side and transmitting only the data required for display, users can efficiently view and zoom into very large images over the web. The Reformatter enables clients to view large, high-quality images and their associated metadata in standard web browsers without the need for a plug-in, Java applet, or other client side software.

Aware Batch Processor

ArchivePack provides for quick and easy conversion of files to JPEG 2000 for the
building of archives. 

Scripts are provided for automatically creating JPEG 2000 images from existing TIFF, JPEG, BMP or RAW images. Metadata can be entered at any time after the creation of the JP2 file or systematically included via scripting as part of the compression process. 

Aware JPX SDK

The .JP2 image file format provides for basic metadata storage capabilities, as defined in Part 1 of the JPEG 2000 standard. The JPX file format significantly extends the metadata storage capabilities, and is defined in Part 2. 

JPX images include an image data block and a set of meta data boxes wrapped into one standard compliant file format. The JPX standard defines the type of meta data that can be held in each box. The Aware JPX SDK and toolkit allows users to add or delete boxes from a JPX image and it allows them to retrieve or modify the values stored in those boxes.

ArchivePack provides full compliance with the JPX format, and allows developers to design applications that take full advantage of its capabilities, such as further color space flexibility, composition, animation, and extensive search features. Importantly, ArchivePack allows JPX files to be created that are compatible with the JP2 format and can be opened by JP2 readers. 

ArchivePack also provides a JPX Metadata Editor and example program to help developers and users make the most of JPX.

 

Why JPEG 2000 for Digital Archives

Preserving rare documents and photographs presents certain challenges for which JPEG 2000 is well suited. Archivists must balance the need for providing public access to special collections while preserving them for future generations. 

JPEG 2000 is a new international standard (ISO 15444) for image compression that uses a wavelet technique to overcome the image quality and functional limitations of current image formats. JPEG 2000 provides a lossless compression option for preservation of digital images. 

When combined with the Aware JPEG 2000 Image Server, these high-quality images can also be made available on the web. Navigation and display of large archive quality images on a remote client becomes very efficient using this standard based technology.

JPEG 2000 offers several benefits that make it an ideal solution for creating digital archives:

JPEG 2000 Facilitates Collaboration

Collaboration is fundamental to the mission of most archives. They may wish to transfer batches of image files and metadata to third parties in order to share responsibility for long-term custody or to build union repositories for access. Many digitization projects have been based on digitization at individual institutions for contribution to a "union" site. 

The ISO standard-compliant nature of JPEG 2000 and its embedded support for multiple types of metadata helps to ensure that, when used to create digital archives, the content outlives the systems that created it.

For digital archives, the value of JPEG 2000 is in its "openness."

The image objects are self-contained for the long term.

• Interoperability of the data can be assured as long as each system is compliant with the standard.
• Implementations and tools to support the standard will be widespread.
  
• Eliminates the need and expense of proprietary compression. 

5000 & 7000 pixel image compressed 20:1.By encoding it in tiles of 512 x 512, and five resolution
layers per tile, this very large image can be efficiently decoded and managed for viewing.

Rich Support for Metadata

The comprehensive and flexible nature of metadata support within JPEG 2000 makes it ideal for digital archives.
Part 1 baseline JPEG 2000 supports embedded metadata in the following ways:

1. Inclusion of comments directly in the codestream: The comments can be either ISO Latin 15 text or binary in format. The length of each text string can be up to 64 kbytes and the text strings can be placed in the main file header or the header for each tile if the image is tiled 

2. JP2 File Format: JP2 is an optional file format that may be used to wrap JPEG 2000 codestreams. The file format includes capabilities to specify the colorspace of the image, alpha channel information, and large amounts of metadata. Multiple JPEG 2000 codestreams can be wrapped into a single JP2 file. All information in a JP2 file is included in entities called "boxes". For example, a specific box type is used to include a JPEG 2000 codestream, a different one is used to include colorspace information.

The JP2 file format defines the following box types for the inclusion of metadata into the JP2 file:

• Intellectual Property Box - Used for carrying intellectual property
  rights information about the image(s) in the file.
  
• XML Box - Used for vendor specific information in XML format. 
  
• URL Box - Used for including an URL that can be used by an application to acquire more information about the associated image or vendor.
• UUID Box - Used for any other information not covered by above metadata boxes.

The UUID box is the most versatile metadata mechanism. It allows the user or application to associate any type of information with the image file in a specific place. Decoders that are designed to read JP2 files with this information included can extract it easily, while others can disregard it completely. 

Losslessly compressed image (Ratio of 2:1) 
Whole image encoded in 5 quality layers.  The quality layers  within each tile can be
individually decoded and represent rations of 12:1, 20:1, 30:1, and 50:1. 

 

Scalability

The JPEG 2000 standard was designed to support the efficient electronic dissemination of digital documents and images to multiple end users. A properly designed system can leverage the encoding and decoding options of JPEG 2000 to provide end users with Just Enough Quality delivered Just in Time.

Resolution Scalability
JPEG 2000 allows reduced resolution images to be quickly and efficiently extracted from a compressed file. This capability is useful for generating index or catalog pages with thumbnails of each image. With JPEG 2000, sub resolution images of various size can be extracted from the single compressed file and do not need to be stored separately.

Quality Scalability
JPEG 2000 also allows reduced quality images to be extracted from a compressed file, producing images with higher effective compression ratios optimized for specific workflows.

Lossless Compression and Lossy Decompression

This implementation of quality scalability elegantly supports remote viewing and access of large losslessly compressed image files. For archival and reference purposes, a lossless image at 2:1 compression can be stored on the server. From this master file, a medium quality image at 30:1 compression can be extracted and transmitted for browsing, and a high quality image at 10:1 compression can be extracted and viewed for most research. JPEG 2000 allows the more highly compressed images to be quickly extracted from the single master file. With the layered file format, only the additional layers must be transmitted to progress to a higher quality image.

Progressive Display

JPEG 2000's progressive transmission format displays a low resolution version of an image after only a small portion of the file has been received. As more data arrives, the display is progressively refined until the full resolution image is shown. This feature allows a user to quickly orient themselves to an image, reducing the time spent waiting for data to arrive.

User interface for the Aware large image encoder/decoder tool (source code included) -
This shows Resolution 2 of 5 for each tile. Those tiles bounded by
red overlay have yet to be fully decoded.

 

Tiling

The JPEG 2000 standard includes support for the tiling of images. This is particularly useful for both the encoding and decoding of very large images. Images can be compressed in rectangular tiles of any size. Only those tile parts of interest or those parts that can fit on the display screen need be decompressed for viewing. Additionally, each tile can be compressed and decompressed by resolution or quality. A very large image can be "encoded" in tiles and each tile can be encoded by resolution layers or quality layers. The "parsable" codestream feature of JPEG 2000 provides a very flexible method by which to efficiently decode and display large images.

Example of how each tile can be independently decompressed by resolution or quality -
decompressing each tile to it’s lowest resolution or intermediate
resolution provides for efficient display of very large images.

 

 

Region of Interest Encoding

Region of Interest (ROI) encoding allows important image features to be compressed at a higher quality than the background, trimming file size without sacrificing important details. When combined with progressive display, ROI encoding also allows the foreground to be transmitted and displayed first, followed by the image background.