Help Page for JPEG 2000 Image Format Files
What is JPEG 2000?
How do I look at JPEG 2000 files?
(Note: The NAIP08 county files are the
first data that MnGeo has distributed in JPEG 2000 format. We will add
information to this page as we use the format more extensively. If you
have suggestions for additional information to provide, please let us
know: clearing.house@state.mn.us
)
What is JPEG 2000?
JPEG 2000 is a wavelet-based data format that allows image files to be substantially compressed with little to no
loss of image quality. This format, created by the
Joint
Photographic Experts Group committee, allows
you to view any portion of a JPEG 2000 image at any resolution very
quickly. It is similar to MrSID and
ER Mapper
formats; however, it is based on an open standard so it can be used by
anyone.
For more information:
How do I look at JPEG 2000 files?
You may look at JPEG 2000 files with some web browsers or with some
geographic information systems (GIS) software packages.
Note: USDA reports that ER Mapper and some earlier ESRI software
releases have had trouble converting NAIP JPEG 2000 formatted files. They
are working to resolve those problems.
- Plug-in for web browsers (free)
If you want to see JPEG 2000 images using either Internet Explorer or
Mozilla Firefox web browsers (Windows versions), you can use LizardTech's
ExpressView Browser Plug-in
(formerly called the MrSID Browser Plug-in). It is free for individual use; download it and follow the
installation wizard instructions.
LizardTech maintains a
Frequently-Asked Questions page specifically for the plug-in.
- Free data viewers
The Farm Service Agency's Aerial Photography Field Office provides an
information sheet about several software packages that can view
JPEG 2000 (note that some do not recognize the 4th band in a 4-band
image).
- ESRI's ArcGIS software
MnGeo has tested ArcGIS 9.1, 9.2, and
9.3 and the software comes enabled to view
JPEG 2000 files. For more details, search for the keyword "JPEG 2000" in ArcGIS
Help. Other questions may be answered at
ESRI's Support Center website.
ArcGIS Tips: If your JPEG 2000 image is composed of more than one
band, you can display either a composite image or any individual bands.
- NAIP 2008 example:
NAIP08 color
imagery is composed of four bands. To see a composite view, choose "Add Theme" and make sure you have
selected the image name (not the individual band names that appear as
"subdirectories"). This will add three bands and will display them with
the red/green/blue color assignments that are set under the
Tools/Options/Raster menu. In ArcMap, if you double-click on the image
name when you add a theme, you will open a listing of the bands and can
choose an
individual band to add instead of the composite.
-
To
change the band color assignments: Right-click on the layer name
and choose "Properties". On the "Symbology" tab, left-click on a band
name to see a dropdown menu of band names. Choose the band you want to
display as the color. Click "OK". (Click on graphic to right to see more
detail.)
- To view the NAIP08 composite as natural color, set:
Band 1 = red
Band 2 = green
Band 3 = blue
- To view the NAIP08 composite as color-infrared, set:
Band 4 = red
Band 1 = green
Band 2 = blue
- "Washed out" image problem
in ArcGIS 9.3
If the NAIP 2008 photos (or any other 4-band imagery) look washed
out or transparent when viewed in ArcGIS 9.3, the "Alpha" channel needs
to be unchecked.
Problem: In ArcMap 9.2 only three channels (or bands: blue,
green, red) could be displayed in a raster image. Starting in ArcMap 9.3
four channels are now displayed by default. Since the fourth channel
(the "Alpha" channel) for NAIP 2008 imagery contains the infrared data
this tends to interfere with or wash out the red, green and blue
channels.
How to Fix: Right-click the image layer in ArcMap's table
of contents. Then select Properties followed by the Symbology tab of the
Layer Properties dialog (click on image shown at right to see more
detail). Make sure RGB Composi
te is selected in the box under Show and
then uncheck the box to the left of the Alpha channel as shown. This
will turn off the Alpha channel so that it will not interfere with the
other image channels. Finally, click the Apply and OK buttons on the
dialog and the image should redraw clearly without the wash out effect.
Note: If you reopen the Layer Properties dialog for the NAIP
2008 image layer, the Alpha channel box is rechecked despite your previous effort to turn it off. This is a bug in ArcMap 9.3 that will hopefully be fixed in the next
service pack. Fortunately, however, ArcMap's automatic rechecking of the
box has no effect and the image will continue to be displayed without
the wash out. If you wish to view the Alpha channel, uncheck it
and then recheck it again and it will become visible.
- ESRI's ArcView 3.x software
Download the
GeoJP2 (TM) ArcView Plug-in from LizardTech's website. The download
package includes a README file with installation instructions. Note that
it does not state that it will recognize the 4th band in a 4-band image.