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Upgrading.

If you did not order V6.70 of TNTview in advance and wish to do so now, please contact MicroImages by FAX, phone, or email to arrange to purchase this version. When you have completed your purchase, you will be provided an authorization code.  Entering this authorization code while running the installation process allows you to complete the installation of TNTview 6.7.

The prices for upgrades from earlier versions of TNTview are outlined below.  Please remember that new features have been added to TNTview with each new release.  Thus, the older your version of TNTview relative to V6.70, the higher your upgrade cost will be.

Within the NAFTA point-of-use area (Canada, U.S., and Mexico) and with shipping by UPS ground.  (+50/each means US$50 for each additional upgrade increment.)

For a point-of-use in all other nations with shipping by air express.  (+50/each means US$50 for each additional upgrade increment.)

Installed Sizes.

Loading TNTview 6.7 processes onto your hard drive (exclusive of any other products, data sets, illustrations, documentation files, …) requires the following storage space in megabytes.

TNTedit™ 6.7

Convert Map Layouts to Scalable Vector Graphics (SVG).

You can now convert map layouts prepared in TNTedit to the W3C’s Scalable Vector Graphics (SVG) layout file in an XML structure.  The Editorial and TNTmips sections and several color plates in this MEMO discuss this new layout structure in considerable detail.

You can also print your map layouts to an SVG file(s) even if you do not have the P15 large format printing option for your TNTedit 6.7. Just as in other “print to” formats previously available in TNTedit (for example, PDF, Illustrator, EPS, and so on), this SVG file will have reduced coordinate values that have been rescaled to preserve only that accuracy needed to print to 11" by 17" size at 300 dpi.  The rasters in the TNT layout will also be rescaled to fit into their position in the layout at the 300 dpi resolution. 

Large Format Printing Option.

The P15 Printing option can now be purchased as an option, the only option, for TNTedit.  It provides for direct printing to any size greater than the basic maximum 11" by 17" printing included as standard in every TNTedit.  It also permits unrestricted conversion of TNT layouts via the “print to” capabilities into TIFF, EPS, Illustrator, PDF, and the new SVG layout files.

Advanced Label Placement.

Automatic Polygon Labeling.

Automatic label generation now attempts to fit the polygon label inside the polygon at the horizontal position wide enough to contain the label with preference given to the span that contains the centroid.  If the label will not fit in the widest horizontal span, it selects one of the adjacent (common boundary) polygons for the label and adds a leader line.  As a last resort, it will place the label over the center of the polygon regardless of its width (a common result for very small polygons).  The polygon label placement dialog now also provides a Clip Under option.  This will clip open a hole for the label text in the polygon fill and every other element in that layer.

Automatic Line Labeling.

Short individual lines can automatically be assembled into a single, longer virtual line by matching their attributes.  A single label is then placed at the center of the virtual line.  The way labels conform to an irregular line shape at the automatically located position can now be selected to follow the irregular line exactly, follow a spline, or an angled straight line.  The vertical placement of the line’s label can now be selected as Top, Bottom, or Centered on the line.  When the label is centered on the line, it can be bisected by the line or the Clip Under option can be used to open a gap for the label in the line and any other lines in that object.

Advanced Label Editing.

Screen Labels.

You can now automatically pan to every label in a layer while zoomed in to locate labels that need to be repositioned.

Slide Line Labels.

A line label attached to a line can now be interactively slid along it in either direction to a new position.  Its curved or straight alignment and above, in, or below baseline property will be maintained.

Drag and Drop Polygon Labels.

Individual polygon labels can now be interactively selected and dragged to a new position. If the label is dragged out of the associated polygon, a straight leader line will automatically appear leading back to its original position.  You can select a position on this leader line and pull it out, rubber band fashion, so that it will have a dogleg.  The free end of the leader line can also be grabbed and moved to some other position within the polygon.

Change a Label’s Appearance.

A new interactive polygon text label size and orientation tool is available.  It permits the position, orientation, and size of a label to be interactively adjusted.  If a label is moved outside its polygon a leader line is automatically added.  A single label can be restyled including its font and colors, by adding bold, italics, outline, or underline, which can also be controlled by the new italics angle, boldness, and other settings.  Multiple line labels can also be created with the various alignment options (including justification) and word wrap.

Inherited New Features.

The following general improvements in all TNT product operations are automatically available in TNTedit 6.7.  These improvements are detailed below in the major section on New Features for TNTmips and include:

• use the new Windows desktop or the familiar X desktop,

• directly display georeferenced JP2 (JPEG2000 compressed lossy or lossless) rasters, …,

• import JP2 (JPEG2000 compressed lossy or lossless) rasters, …,

• convert a map layout to a Scalable Vector Graphics (SVG) XML layout,

• use transparency for 16-bit rasters (IKONOS, QuickBird, …)

• include legend samples for elements rendered via CartoScripts or other scripts in Legend Views and map layouts,

• use word wrap and justification in text blocks in map layouts,

• control advanced text features (italics angle, outline thickness, boldness, …),

• control labels by scale and pan to each label, and

• embed fonts into PDF files to improve their portability, scalability, and the rendering of tiny characters.

Upgrading.

If you did not order V6.70 of TNTedit in advance, and wish to do so now, please contact MicroImages by FAX, phone, or email to arrange to purchase this version. When you have completed your purchase, you will be provided an authorization code.  Entering this authorization code while running the installation process allows you to complete the installation of TNTedit 6.7.

The prices for upgrades from earlier versions of TNTedit are outlined below.   Please remember that new features have been added to TNTedit with each new release.  Thus, the older your version of TNTedit relative to V6.70, the higher your upgrade cost will be.

Within the NAFTA point-of-use area (Canada, U.S., and Mexico) and with shipping by UPS ground. (+$50/each means US$50 for each additional upgrade increment.)

For a point-of-use in all other nations with shipping by air express. (+$50/each means US$50 for each additional upgrade increment.)

Installed Sizes.

Loading TNTedit 6.7 processes onto your hard drive (exclusive of any other products, data sets, illustrations, Word files, and so on) requires the following storage space in megabytes.

QuickGuides

9 new 1-page QuickGuides listed below are enclosed with V6.70, bringing to 42 the number provided in printed form with each new TNTmips product.  If you have suggestions for QuickGuides that might help you or others as quick references to special features, please let us know.

All 42 QuickGuides can be downloaded in Adobe Acrobat Reader PDF from http://www.microimages.com/didyouknow/.

Tutorial and Reference Booklets

There are now 70 TNT Tutorial and Reference booklets (formerly called Getting Started Booklets).  These booklets provide 1700 pages and over 3800 color illustrations.  Many are up-to-date with the features in V6.70 of the TNT products, some are not. Each new professional TNTmips ships with 3 thick notebooks containing a color printed copy of every booklet.  Those of you receiving your V6.70 upgrade on CD can view and refer to any booklet using Adobe Acrobat Reader.  If you install all these booklets as part of any TNTmips product, you can directly access these booklets via Help / Tutorial Overview.

An online, searchable, cross index covering all the booklets and online documentation is now available from the help menu.

New Booklets Available.

Five new GSBs are being released for the first time with TNT V6.70 and are shown in the attached color plate entitled New Tutorial and Application Booklets.  They are:

• Advanced Vector Editing,

• Using TNTsim3D for Windows (latest version matching TNTsim3D 6.7 is not on V6.70 CD, please download),

•  Building 3D Landscapes,

• Making Geologic Maps, and

• Making Topographic Maps

Expanded Booklets.

Seven TNT booklets have had significant upgrades for use with V6.70 of the TNT products.  They are:

• Displaying Geospatial Data

• Navigating,

• Making Map Layouts,

• Feature Mapping,

• Building 3D Landscapes, and

• Pin Mapping.

Translated Booklets.

Additional translated tutorial booklets continue to be added to the list.  A good portion of the booklets, some of the QuickGuides, and other materials are now available in Spanish.  The first booklets are available in Russian and Bulgarian. You can determine which booklets are available in your language at any time and obtain them from the “Download” listings at microimages.com/getstart/.  A color plate is attached entitled Translated Documentation to emphasize the availability of these materials.

New TNTmips Features

Main or subsections preceded by the asterisk “*” symbol introduce significant new processes or features in existing processes released for the first time in TNTmips 6.7.

System Level Changes.

* Windows or X Desktop.

When you start up TNTmips 6.7 within Microsoft Windows, you are now presented with a small Interface Type dialog to select the familiar TNT X desktop or the new TNT Windows desktop. The attached color plate entitled Windows Desktop or the X Desktop illustrates both of these desktops.

X Desktop.

If you choose the familiar X desktop option, you will be using the same full screen X window approach as in previous versions of the TNT products.  One large X window appears providing your TNT desktop or work area and all other TNT visual interface components appear inside this large window.  As you know, this X desktop can be set to any size you wish if your TNTmips is authorized to level M50 (the only version of TNTmips sold for the last 2.5 years—since V6.30). 

There are sizing options for you to use to set up your X desktop.

1) The X desktop can be deliberately set smaller than your display screen to expose some of your normal Windows area outside the main X window.  This will permit you to see other programs’ windows and click on them to make them move to the front and become the active window for your input.  Since you can also move any running program to the foreground using its task bar representation, this smaller X window is seldom used. 

2) The main X window size can be set to equal your screen(s) display area.  This full screen X window will open to hide the windows of any other active programs.  They can immediately be moved in front of this X window by selecting them from the task bar. 

3) The third option, unique to the TNT products, is to set up a virtual X window, which is much larger than all the area of your display screen(s).  This creates a virtual X desktop for large map size displays and instant access to any part of it and the many control windows used in TNTmips.

Windows Desktop.

The new TNT Windows desktop option makes the TNTmips interface components appear and function just like any other active windows.  In this mode, MicroImages’ X server projects each TNTmips window into the Microsoft Windows desktop using the same functions as native Windows.  Thus, your TNT windows appear on your Windows desktop as separate windows and move, resize, close, and operate like any other open windows.  All these TNT windows also appear on the task bar. 

While you are not able to functionally distinguish these separate TNT windows from those of other native windows programs, you are still running MicroImages’ X server in the background.  You are not running a native Windows version of TNTmips, TNTedit, or TNTview, it just looks as if you are!  Thus, even though you now have a native Windows desktop, it does not provide ActiveX components or permit communication with other Windows processes via OLE, COM, Visual Basic, and so on.

Making a Choice.

New users of TNTmips will find comfort in finding and using all the TNT windows and dialogs on the familiar Windows’ desktop.  Before the Windows desktop was available, the comment often heard from someone looking over your shoulder was “But, its not Windows!”  Now, if you do not tell them, they may never realize that it is not.  Those who become experienced in the operation of TNTmips will gradually discover and accept the differences (some good some not).  Eventually, they will become sufficiently experienced to realize that TNTmips is not a single program, but a complex analysis system a bit like a simple, but specialized operating system.  It has a common geodata file system and file management tools and performs many different but interrelated analysis operations on these files.  Each of these operations may present several interrelated windows and dialogs.  Thus, as you become an experienced user, you may choose the full or virtual screen X desktop mode that focuses all your attention on the integrated nature of geospatial analysis as you engage in progressively more complex activities.

The new Mac OS X versions of the TNT products function just like the new optional Windows desktop.  Each TNT window appears and operates in a native Mac Aqua window, but is still formed from an X window. Switching between the X and Windows desktop on a Microsoft based platform is a matter of preference and is no different now than switching from a Windows desktop to a Mac desktop. There is no equivalent to the full screen X desktop option for Mac OS X.  Linux and UNIX platforms can operate more or less like either of the Windows’ desktop modes depending on the window manager selected.  However, for all these different desktops and their windows’ cosmetic differences, your TNT products will present the same windows, dialogs, options, and operations. 

Changing Your Mind.

Unless you toggle it off, the Interface Type dialog will continue to provide you the opportunity to start either the Windows desktop or X desktop each time you start the X server.  Leave it on for a few days until you have experimented thoroughly with each approach.  If you have selected the Windows desktop mode and exit TNTmips, the X server is not closed and is treated as a suspended utility.  Take careful note that there is a small X icon in your system tray (which means, at the right end of the task bar).  This costs nothing and saves time when you restart a TNT product.  However, if you restart TNTmips, it will not present the Interface Type dialog as you have not restarted the X server, so it appears that you can not switch modes.  Simply use your right button on the small X icon on the toolbar to expose and use its Exit menu option.  Now, if you restart TNTmips you will again get the Interface Type dialog box (unless you toggled it off previously).

Once you have toggled off the Interface Type dialog, use the following procedure to change between the desktop modes while running TNTmips.  Use your left mouse button on the X icon in your system tray (which means, at the right end of the task bar) to expose the MicroImages X Server Preferences dialog. On this dialog select the Options tabbed panel, and scroll through the Extensions and Server Options.  The check box for the option to Run in Rootless Mode switches the X server between desktop modes  [Rootless Mode - see how programmer’s jargon manages to creep in no matter how hard you try to stamp it out].   Remember that you then have to Exit the X server to get this change to take effect when TNTmips restarts it.

Customizing Menus and Running Your Programs.

There have been several recent inquiries that indicate it is not well understood how to customize your TNT menus.  This is done by simply editing the file tntmips.mnu with WordPad or any other text editor.  In this fashion, you can modify your TNTmips menus to move or delete TNT processes and to access SML scripts, processes you develop with TNTsdk, or programs developed with other tools such as Visual Basic.  The procedures for modifying all TNT product menus (including TNTatlas) are outlined in the attached color plate entitled Customizing TNT Menus.  Note that it illustrates how a Visual Basic program can be started from the menu.  When it is run from the menu, it runs as a separate task with its own active window(s).  If you are using the new TNT Windows desktop, you could now also see and access this program’s windows.  You are still running TNTmips, so when you quit this program, you can continue on with subsequent TNT processes.

Your Visual Basic program could incorporate the TNTsdk C++ functions to read and/or write objects to or from a Project File.  Thus, this Visual Basic program could operate on TNT objects and modify them for use in subsequent TNT processes.  Manipulating TNT database objects, such as collecting user input with a form, would be one example of this kind of operation.  Of course, there are many other functions you could call in the TNTsdk.  Alas, the powerful TNT Graphic Rendering Engine is not a function. 

Miscellaneous.

In all object selection dialogs, the “Add All” button now adds objects in the order they are selected and shown rather than the order they are in the file.  This allows control of the order by appropriate naming in cases where the order is significant such as the harmonic analysis process.

The message text formatting system was redesigned to permit changing the order of substitution parameters when translating messages.  Previously these had to be retained in the original order.  Translators may now arrange the values in their desired order to provide better readability in their language.  For example the text

• 3D vector from raster ‘$1$ and vector $2’ “ can now be rearranged as

• 3D vector from vector ‘$2’ and raster ‘$’ 1”.

Geospatial Display.

* Vector Element Selection.

When a query, script, or other control operation is used to select a subset of elements from a vector object for display, only the labels attached to those elements are drawn into the view.

The Table Editor dialog used for the selection by attributes of the element to render has been revised.  This dialog now permits the selection of any attribute rather than being limited as in V6.60 to a “primary key” attribute.  The new dialog design is simpler to use with intuitive checkboxes for selecting/unselecting attribute records.

* Label Scale Control.

Add “scale range” option for label elements to suppress labels when they would be drawn too small or dense to be readable.  Use this option to improve the appearance of vector objects with many dense labels. 

Miscellaneous.

You can now manually add “representative elements” to legends (both in LegendView and a multi-object legend layer in a layout) for vector objects styled by script.  This is done using the right mouse button after selecting an element in the GeoToolbox.  These legend entries are stored in a database table associated with the elements, which can easily be edited later to change labels and text, remove legend items, and so on.  This feature is discussed in more detail in the Legends section of this MEMO.

Transparency is now supported for any 16-bit rasters (for example, IKONOS and QuickBird)

The appearance of the relief shading of signed rasters was improved.

A user-specified color palette is stored with the group or layout if not saved as a palette object with a raster layer.  This reduces the need to save the palette especially for cases where a layout-specific palette is desired or where the raster object is not writable such as on a CD or linked and set as read-only.

* JPEG2000 Compression Using Discrete Wavelet Transformation (DWT).

Background.

What is the Situation  in Commercial Offerings?

Previous MicroImages’ MEMOs have reported on the progress and legal entanglements of 2 other wavelet based still image compression methods:  LizardTech’s MrSID and Earth Resource Mapping’s ECW.  These earlier methods emerged to take advantage of wavelet concepts in the absence of an ISO approved JPEG2000 standard.  They provide specific proprietary approaches to the application of wavelet compression concepts to grayscale and color picture compression (MrSID) and remote sensing applications (ECW).  V6.60 of the TNT products provides you with the ability to link to, or import images that you obtain in these proprietary compressed formats on the specific platforms their manufacturers support (generally limited to Windows).  V6.60 also provides the ability to produce ECW images up to the 500 Mb limit, which they permit other software vendors to provide without additional charges. Creating ECW files greater than 500 Mb is provided by the compressor included in the ER Mapper product. Creating MrSID files of any size requires the purchase of their “stand-alone compressor” product.

A careful search of the WWW in late June provided no information with regard to the implementation of JPEG2000 compression in PCI Geomatics, ENVI, or ERDAS products.  A similar review of their web sites could not identify any capability of this type.  In May Earth Resource Mapping released a marketing document part of which is devoted to comparing still image wavelet compression products and results.

Accelerating WebGIS (ArcIMS® et al) with Image Web Server.  Technical Overview and Performance Analysis.  17 May 2002.  prepared by Earth Resource Mapping.  22 pages.

This is an important reference, which can be downloaded from 

www.ermapper.com/marktng/articles/pdf/accelerating%
20webgis%20with%20image%20web%20server.pdf

While the map server portion of this document may be of interest, pages 15 to 21 present tables entitled Image Format Features Comparison, Compressed Image Technology Capabilities, and Compressed Image Technology SDK’s.  These comprehensive tables compare in considerable detail the ECW, MrSID, JPEG2000, JPEG, and compressed GeoTIFF formats.  The tables also compare prices, limitations, efficiencies, and other aspects of using these formats. 

In general, the entries in these tables for these competitive compression schemes appear correct.  However, as noted in the footnotes to many entries, the JPEG2000 limitations reported represent limitations of LuraTech’s JPEG2000 proprietary library implementation, not the JPEG2000 ISO standard.  In comparison with these entries for the LuraTech approach, MicroImages’ implementation of JPEG2000 compression uses a different library that overcomes these LuraTech imposed limitations.  For example the TNT JP2 file size is unlimited (not the 2 Gb in this table), 16,384 spectral bands (not 255), data value precision is 38 bits (not 23 bits), and georeference information is provided.  When these adjustments are made to the Image Format Features Comparison table, JPEG2000, an open standard ISO format equals or surpasses ECW, MrSID, and LuraTech’s JPEG2000 in each category where each of our marketing and implementation strategies vary with regard to creating, buying, and using wavelet compression methods. 

Finally, controlling compression and the efficiency of the end use of the file achieved also varies widely between these and the TNT products.  For example, can the level of compression be controlled and how is it specified (for example, lossless, 18 to 1, …),  how fast is the decompression in some other end user product (for example, a free geoviewer), does their display permit streaming only to the pixel resolution of the display (for example, stopping at the resolution of the display device), and so on.  These Earth Resource Mapping tables do not cover these kinds of practical end user considerations as they are difficult to compare when you are providing files for use in a variety of other vendors’ products.

What does the ISO Standard Encompass?

Please keep in mind that JPEG2000 has been designed for a wide variety of image applications such as streaming high resolution TV (for example, HDTV) to produce manageable band width requirements.  To provide you with a better grasp of what objectives can be achieved by the JPEG2000 standard for use with still images, the following paragraphs in italics have been reproduced directly from the introductory portion of the article:

The JPEG 2000 Still Image Compression Standard. IEEE Signal Processing Magazine.  by Athanassios Skodras, Charilaos Christopoulis, and Touradj Ebrahimi.  Sept 2001, V18, N5.  pp. 36-58.

“Why Another Still Images Compression Standard?

“The JPEG standard has been in use for almost a decade now.  It has proved a valuable tool during all these years, but it cannot fulfill the advanced requirements of today.  Today’s digital imagery is extremely demanding, not only from the quality point of view, but also from the image size aspect.  Current image size covers orders of magnitude, ranging from web logos of size less than 100 Kbits to high quality scanned images of approximate size of 40 Gbits.  The JPEG 2000 international standard represents advances in image compression technology where the image coding system is optimized not only for efficiency, but also for scalability and interoperability in network and mobile environments.  Digital imaging has become an integral part of the Internet, and JPEG 2000 is a powerful new tool that provides power capabilities for designers and users of network image applications.

“The JPEG 2000 [ISO] standard provides a set of features that are of importance to many high-end and emerging applications by taking advantage of new technologies.  It addresses areas where current standards fail to produce the best quality or performance and provides capabilities to markets that currently do not use compression.  The markets and applications better served by the JPEG 2000 standard are Internet, color facsimile, printing, scanning (consumer and prepress), digital photography, remote sensing, mobile, medical imagery, digital libraries/archives, and E-commerce.  Each application area imposes some requirements that the standard, up to a certain degree, should fulfill.  Some of the most important features that this standard should possess are the following:

“Superior low bit-rate performance:  This standard should offer performance superior to the current standards at low bit rates (e.g., below 0.25 bpp [bits per pixel] for highly detailed gray scale images).  This significantly improved low bit-rate performance should be achieved without sacrificing performance on the rest of the rate-distortion spectrum.  Network image transmission and remote sensing are some of the applications that need this feature.

“Continuous-tone and bilevel compression:  It is desired to have a coding standard that is capable of compressing both continuous-tone and bilevel images.  If feasible, this standard should strive to achieve this with similar system resources.  The system should compress and decompress images with various dynamic ranges (e.g., 1 to 16 bits) for each color component.  Examples of applications that can use this feature included compound documents with images and text, medical images with annotation overlays, and graphic and computer generated images with binary and near to binary regions, alpha and transparency planes, and facsimile.

“Lossless and lossy compression:  It is desired to provide lossless compression naturally in the course of progressive decoding.  Examples of applications that can use this feature include medical images, where loss is not always tolerated; image archival applications, where the highest quality is vital for preservation but not necessary for display; network applications that supply devices with different capabilities and resources; and prepress imagery.  It is also desired that the standard should have the property of creating embedded bit stream and allow progressive lossy to lossless buildup.

“Progressive transmission by pixel accuracy and resolution:  Progressive transmission that allows images to be reconstructed with increasing pixel accuracy or spatial resolution is essential for many applications such as web browsing, image archival and printing.

“Region-of-interest (ROI) coding:  Often there are parts of an image that are of greater importance than others.  This feature allows users to define certain ROIs in the image to be coded and transmitted in better quality and less distortion than the rest of the image.”  [Note, this is not the same use of the term ROI as used in the TNT products.]

“Open architecture:  It is desirable to allow open architecture to optimize the system for different image types and applications.  With this feature, a decoder is only required to implement the core tool set and the parser understands the code stream.

“Robustness to bit errors:  It is desirable to consider robustness to bit errors while designing the code stream.  One application, where this is important, is transmission over wireless communication channels.  Portions of the code stream may be more important than others in determining decoded image quality.  Proper design of the code stream can aid subsequent error correction systems in alleviating catastrophic decoding failures.

“Protective image security:  Protection of a digital image can be achieved by means of different approaches such as watermarking, labeling, stamping, or encryption.  JPEG 2000 image files should have provisions for such possibilities.”

What is MicroImages’ Approach?

As part of the JPEG2000 international design and ISO adoption process, all those companies participating in and contributing patented or copyrighted concepts into JPEG2000 agreed to abrogate or granted free licenses for use in this standard.  This has permitted members of the standardization committee to develop libraries for the implementation of JPEG2000 support in other products that are free of legal entanglements at this time.  After an examination of the available libraries, MicroImages purchased the unlimited and source code rights to use the Kakadu libraries (Kakadu is Australia’s largest national park, see www.kakadusoftware.com).  These libraries were developed by Dr. David Taubman, Senior Lecturer in Telecommunications, School of Electrical Engineering and Telecommunications at the University of New South Wales (www.ee.unsw.edu.au/staff/taubman). 

Dr. Taubman is a central figure in the JPEG2000 standards movement and author of a new definitive 773 page book containing all the technical and mathematical details of JPEG2000.

JPEG2000: Image Compression Fundamentals, Standards and Practice.  eds. David S. Taubman and Michael W. Mercellin.  2002.  Kluwer Academic Publishers, The Netherlands.  773 pages.  (ISBN 0-7923-7519-X)

For a synoptic technical introduction to JPEG2000 you can also see:

A Tutorial on Modern Lossy Wavelet Image Compression:  Foundations of JPEG2000.  IEEE Signal Processing Magazine.  by Bryan E. Usevitch.  Sept 2001, V18, N5.  pp 22-35.

V6.70 of the TNT products uses the Kakadu library to implement almost all the meaningful JPEG2000 still image features in ISO Part 1 for all the TNT supported operating systems.  Since JP2 files are in a standard format, they can also be moved between operating systems without alteration.  ISO Part 2 is still under consideration at this time and will standardize some additional characteristics such as how to include image georeferencing (the TNT V6.70 procedure is discussed below).  However, most of what will be standardized in Part 2 concerns other kinds of images and will not be pertinent to still images and your use of them.  MicroImages awaits the official publication of Part 2 and will extend JPEG2000 support to encompass its new features as soon as they are available.

Using JPEG2000.

JP2 files can be used in TNT products except in TNTsim3D.  TNTatlases can be drastically reduced in size, if appropriate, by using linked, compressed JP2 raster files. A plug-in is available for Adobe Photoshop to support its use of JP2 files.  LuraTech provides a plug-in for Internet Explorer to upgrade it to use JP2 files locally or via a web source.  LuraTech also sells low cost JP2 plug-ins for Photoshop, Paint Shop, and browsers as well as extensions for other packages such as QuarkXPress.  Please search the web or consult the manufacturer of your other software products to determine their support or plans to support JP2 files.

All of the different integer types that can be used in raster objects can be exported to the JP2 format (for example, binary, signed 16-bit or 32-bit integers). The conversion to JPEG automatically transforms color composite images of various types (RGB, HIS, …) into 3 RGB components.  It is important to remember that TNTmips supports many integer raster data types, all of which can be exported to JP2 files.  However, this does not insure that a particular data type in a JP2 file is supported or even useable by other commercial software products (for example, signed 16-bit integers).  You may have to restrict or convert the data types in your TNT raster objects before exporting to JP2 for use in other software products.

Type of Compression.

Lossless Compression. 

As you know, JPEG does not support lossless compression and the lossy level (compression ratio) of JPEG is hard to control.  TNT’s JPEG2000 implementation provides lossless and better control over the level of lossy compression.  However, lossless JPEG2000 is about the same as that used in GeoTIFF or other lossless compression schemes.

As pointed out in the table Image Format Features Compression (see source above), there are differences between proprietary wavelet compression and JPEG2000 implementations.  Lossless compression ratios may increase significantly when images are provided in 16-bit integer files as often these images do not actually need that data type or they do not locally (in most subareas) range widely over the 16-bit data values—unless the image is highly noisy.  Neither MrSID nor ECW provide 16-bit lossless support.  TNT products now support lossless JPEG2000 compression for up to 32-bit integers.

Lossy Compression. 

One of the main objectives of JPEG2000 is to provide vastly improved lossy compression.  At first glance, its 50 to 1 or even 100 to 1 compression seems almost like magic.  This very significant capability is illustrated in the color plate entitled JPEG2000: Compression Results.  However, always keep in mind that if you apply any level and type of lossy compression to an image, you are creating a new image from it. You are not simply changing the format and size of your original image.   The attached color plate entitled JPEG2000: Lossy or Lossless? lists some of the situations in which you can apply lossy compression to raster materials at your discretion.  Lossy compression can be a powerful tool, but you must think about what it does to your image before you use it.

In concept, the wavelet compression used in JPEG2000 stratifies the content of an image by its frequency.  As you increase the amount of lossy compression (increasing the compression ratio), image components with high frequencies are omitted from the new image and JP2 file.  Eventually, as JPEG2000 compression increases, you can begin to visually detect that these kinds of components (high frequency features) are missing from your new image.  This gradual loss of detail contrasts sharply with the visual 8 by 8 pixel artifacts that appear in highly compressed JPEG images.  This is illustrated in the attached color plate entitled JPEG2000 versus JPEG “Classic”.

At low lossy JPEG2000 compression ratios, it may be that image noise is discarded.  However, as compression ratios are increased, the new image, when carefully examined, will show losses in detail.  An example of the “fading detail” is illustrated in the attached color plate entitled JPEG2000: A Closer Look at Compression Artifacts.  You must determine whether or not these losses are significant to your application.  In the attached color plate entitled JPEG2000: Compression Results you do not detect these losses as the printer and scale of the reproductions do not maintain them.  If the printer, display screen, the web application, and so on can not reproduce the detail lost at the desired resolution and scale, then the loss is meaningless.  For these kind of applications, large compression can be very useful. 

The level of compression and the amount of loss you wish to introduce into your JPEG2000 images is up to you.  Lossy compression should never be used with multi-spectral or hyperspectral images that are going to have any subsequent analysis applied.  DEM rasters (as discussed below) can have some losses introduced depending on how they were derived and what they are intended for.  Images that are to be used for backgrounds in image maps can be very compressed when the details in the image will be lost in the printing process.  Lossy JPEG2000 support, when included within the standard browsers, will find extensive application on the web where bandwidth and end user wait-time (which means, patience) is critical, and streaming of resolution detail is expected.

Almost Lossless Compression.

A “Lossy (best quality)” option is available as part of the TNT export to automatically achieve almost lossless compression for many kinds of source materials.  Limiting your lossy compression to this level can provide significant compression in a new raster that is nearly indistinguishable in quality from the original.  Choosing this option or specifying an even greater targeted lossy compression is a decision you are going to have to make.

The DWT process may itself can be lossless or lossy.  In either case the source raster is converted to a Discrete Wavelet Transformation (DWT), which is encoded into a JP2 file.  The difference between the lossless DWT and the lossy DWT is that the lossless DWT is performed using integer computation and uses 7 sequential cells at a time, while the lossy DWT uses floating-point computation and uses 9 sequential cells. 

If the lossless integer DWT is performed, no additional information will be discarded later in the compression process resulting in completely lossless and reversible compression.  The floating point DWT produces the “Lossy (best quality)” and all losses are those automatically minimized by the floating point DWT process.  If you specify a target compression ratio greater than that produced by this initial DWT result, additional information will be selectively discarded from the floating point DWT to achieve your compression ratio.

Compressing only to the “Lossy (best quality)” level takes advantage of the DWT concept and usually causes only very small changes in numeric cell values.  For relatively “smooth” data, such as elevation models, this setting can result in compression rations of 50:1 or greater with acceptable minor loss of precision.  Compressing to a higher targeted ratio produces a JP2 file of known size whose additional losses in quality may be unimportant in your application.

Choosing A Compression Ratio.

Start from Lossy (best quality).

How should you proceed to select the lossy level.  You could arbitrarily let the storage space on your media decide the level of compression to select without regard to what happens to the raster contents.  If this is your choice, simply determine and enter the appropriate compression ratios.  If you want to retain good quality in your images, choose “Lossy (best quality)” and plan to supply the required storage space.  This is also the best choice for exploring new materials or for beginners with limited experience in using JPEG2000 compression on a wide variety of rasters.  Closely compare the “Lossy (best quality)” JP2 raster with the original.  If the results are satisfactory for your application, then rerun that comparison using incrementally higher “Targeted Compression” settings (for example, … 20:1, 25:1, 30:1 …) until you find the maximum lossy compression that retains the quality required for your application with this type of raster.

Sample Application to DEMs.

Compressing Nebraska.

Digital Elevation Models can be highly compressed to lossy JP2 files and the amount of compression can vary widely.  The attached color plate entitled JPEG2000: Almost Lossless illustrates how “Lossy (best quality)” compression changes a 16-bit Digital Elevation Model (DEM) with a 1-meter vertical cell increment. This elevation map of Nebraska at this 90-meter cell size changes little from cell to cell.  It was prepared by USGS from contour maps and the vertical accuracy has Root Mean Square Error (RMSE) of 15 meters.  This makes it an excellent candidate for a small JP2 file for use in many applications. 

As illustrated, almost 88% of the cells are changed only 0, 1, or 2 meters in elevation from neighboring cells while the RMSE of the cell elevation is 15 meters.  On the other extreme, 1 cell in the whole area (46 million cells) was changed by 18 meters, 6 by 17 meters, 16 by 12 meters, and so on.  Overall, 99.99% of all cells were changed by 10 meters or less.

Computing the Discrete Wavelet Transformation (DWT) during JPEG2000 compression is effectively fitting a mathematical surface to the whole state’s DEM that exactly preserves every cell’s elevation.  This description (DWT) is then altered just a little (thus becoming irreversible) to encode it into a much smaller JP2 file. The new surface in the JP2 file has a new elevation value for each cell that varies not at all, or only slightly, from each cell’s original elevation.  The new surface deviates the most in areas of rapid change in relief (2^nd derivative of the elevation / 1^st derivative of the slope).  However, this new approximation of the Nebraska elevation model can be stored in 1/116 of the space and even a larger “targeted” JPEG2000 compression ratio could be applied. 

A careful examination of this sample application illustrates a basic result in JPEG2000 still image compression.  Very small changes, even 1 increment in data value, can result in large compression in the new raster with no visual degradation at any scale.  A corollary to this is that the new image has to have some room to vary just a small amount in value.  For example, a shift of 1 or 2 data values in a 16-bit raster is much less significant than a similar shift of 1 or 2 data values in the 8-bit version of the same raster.  Converting a 16-bit DEM raster to an 8-bit raster gives a 2:1 compression but can have a serious impact on the DEM if the cell values are rescaled to fit in 8-bits. Further compression of this new 8-bit raster to a “Lossy (best quality)” JP2 raster will further degrade this DEM.  However, going directly from a 16-bit DEM to a “Lossy (best quality)” may produce a much smaller file with little distortion.

USA DEM on a DVD.

The following is the latest announcement regarding the availability of the Shuttle SRTM derived DEMs: RADAR DATA RELEASE Aviation Week and Space Technology, 22 July 2002, page 51.

“NASA and the National Imagery and Mapping Agency (NIMA) are releasing 30-meter (98-ft.) radar topographic map data for the entire U.S. collected during the Shuttle Radar Topography Mission (SRTM) flown in 2000.  The agencies also agreed to provide 90-meter (295-ft.) resolution SRTM terrain elevation data from non-U.S. sites to qualified researchers.  Still in discussion is whether to provide the best 30-meter data of non-U.S. areas to the general public internationally.  Those data, which are potentially militarily significant, are saddled with more restrictions.  Data are being processed at the NASA Jet Propulsion Laboratory and NIMA.  High-priority areas, like those in Afghanistan and Iraq, have been processed on an accelerated basis to provide critical terrain data to the Defense Dept.”

These SRTM derived DEMs are generally similar in complexity to the Nebraska DEM used in this illustration.  Their “Lossy (best quality)” compression of 100:1 would yield about a 1 Gb JP2 file for the 90-meter cell size for the United States (about 10 times greater for 30-meter cells).  This size may be larger (2 or 3 Gb) since rugged terrain areas are not represented in Nebraska.  However, it is still going to fit on a single DVD as a single JP2 file.

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