Image Standard Speeds Access
Written by Kate Heightley
Geospatial Intelligence Forum
In the last year, “JPIP image dissemination” has been listed as a requirement in a number of Department of Defense and intelligence community image archive and dissemination programs. Although JPEG 2000 Interactive Protocol (JPIP) has been around for some time, the technology isn’t widely recognized across DoD and the intelligence community.
Why, then, is the JPIP requirement appearing now as part of significant government programs? The answer is timely access to geospatial information.
Geospatial imagery is a critical component of the information needed to obtain situational awareness in defense and intelligence missions. As the use and importance of imagery as information for decision-making has grown, so have the size of individual images and the volume of available image data. As a result, access to information is delayed due to image download time, and has become an obstacle to using imagery in many cases. This is driving JPIP adoption by DoD and IC.
JPIP is a protocol for moving imagery on-demand. JPIP has the unique ability to provide useful information while moving only a small amount of data and still providing access to the full image. Only the minimum amount of image data that is required to satisfy the user’s immediate request is downloaded. This is extremely useful in situations where the bandwidth available to transfer imagery is limited, but is also valuable for managing bandwidth in any visual image exploitation scenario.
JPIP image dissemination allows users to quickly receive the time-sensitive information they need to make mission critical decisions. This unique ability is the main driver for the growing JPIP requirement.
JPIP is part of the JPEG 2000 standard, and represents the language for moving JPEG 2000 image data from the server to the client. The JPEG 2000 format provides both lossy and lossless compression, and also provides layering of the encoded data so that it can be decoded according to resolution, quality and region of interest. A JPEG 2000 image can be thought of as layers of differing quality and resolution. With all of the layers, the full quality and resolution of the original image is displayed.
The JPEG 2000 encoding allows the user to reach into the image and pull out a region of interest from any of those layers and view just that portion. This makes it possible to start out viewing a region of interest at lower image quality and resolution. As the user zooms in, additional image data is downloaded to the client to provide higher quality and resolution, which translates to more visible detail in the displayed image.
Using the concept of layers in an image, the JPIP server starts by delivering the lowest layer (lowest quality and resolution) necessary to satisfy the user’s request. More data is delivered as the user requests greater quality and resolution. This filling in of more data is referred to as progressive rendering. It allows the end-user to access imagery very quickly, and also lets the user zoom to see greater quality and resolution and pan to see additional areas of interest. As image requests are made at the client, image data is interactively transferred via the JPIP protocol. This is referred to as streaming. This is the magic of JPIP. Leveraging the JPEG 2000 format, very small amounts of data provide useful imagery intelligence.
Real World Example
As an example of the application of JPIP technology, let’s look at the disaster response after a devastating earthquake struck Haiti in January 2010. Soon after the earthquake, military and emergency response personnel needed to understand the extent of the damage and find available routes to deliver emergency equipment and supplies.
Figures 1 and 2 show a GeoEye image of Haiti streaming into a Web-based JPIP client viewer from a JPIP server. This image was taken shortly after the earthquake. The two figures are screen captures taken from the initial “image open” request from client to server. Both were captured while image data was actively streaming from the JPIP server to the client viewer.
Figure 1 shows the lowest quality and resolution streaming into the viewer. You can see the general shape of the land mass and tell that it is fairly populated. Figure 2 shows more detail as the data has been progressively rendered to increase quality and resolution. You will notice that there are some tiles along the bottom of the display that haven’t been rendered at the higher resolution and quality yet.
Once the user’s request is satisfied and streaming stops, the viewer is showing a fairly large region of interest at 6.2 percent of the full image resolution, or a zoom level of 1 to 16. Only 2.7 megabytes of the original 688 megabyte JPEG 2000 compressed image have been JPIP streamed from the client to the server in order to satisfy the user’s request. If the user is trying to see if there are any open routes to the point of land in the center of the image, he’ll need to zoom in further.
As the user zooms in a couple of levels, increasing detail streams in, as shown in Figures 3 and 4. In Figure 3, the region of interest is zoomed in to 25 percent of the original resolution, and in Figure 4, the full, or 1 to 1, resolution is shown. In Figure 4, the user can see good detail of the roads in the area and can tell that they look passable. At 25 percent resolution in Figure 3, 5.9 megabytes of the 688 megabyte image have been streamed to the client. And at 100 percent resolution, 9.4 megabytes have been streamed to the client. This represents just over 1 percent of the full image size.
Even in situations like Haiti, where bandwidth was severely limited and was provided only by portable cell towers, responders could still receive the imagery quickly and plan their actions intelligently. It is this ability to provide meaningful imagery information by transferring very small amounts of the image data that has led to the increasing use of JPIP/JPEG 2000 technology.
Image Delivery Methods
For users without access to JPIP technology, traditional image delivery methods delay access to timely intelligence. In these cases, imagery is delivered to the field by shipping or dropping physical media. This means that the end-users must wait for the imagery to be processed, loaded onto the media and shipped for delivery. By the time the imagery is available, it is often too outdated to be useful. This also means that the imagery is copied multiple times and delivered to multiple servers. This requires additional server storage space, and can impact the ability for the provider to maintain control of the imagery.
Alternatively, end-users are provided with partial or low-resolution data subsets delivered over a constrained-bandwidth network. This method often leaves users without the level of detail they need, or with the requirement to figure out which image tile they need, which can waste valuable time when the user must repeatedly request additional tiles. In general, traditional methods for image delivery to the field are often too time-consuming or restrictive to effectively provide timely, mission critical information to those that need it most.
JPIP at the Tactical Edge. Another practical use for on-demand image dissemination using JPIP is for forward-deployed and tactical personnel in defense scenarios. JPIP technologies have been successfully adopted in many defense missions. Today, JPIP technology is deployed in tactical edge situations and is greatly improving the imagery intelligence available to warfighters. Before JPIP systems were available, warfighters had very limited access, if any, to current imagery.
With JPIP, imagery that is only hours old is processed and hosted on servers at or near the collection sites, and made available to deployed personnel via centralized catalogs. The user finds the needed image in the catalog and initiates a streaming request from the client to the server where the image resides. The imagery is streamed to the warfighter in the field, providing situational awareness despite limited bandwidth and austere conditions. This type of on-demand access to timely imagery has significantly improved the ability for forward- deployed personnel to make mission critical decisions.
JPIP and High Bandwidth. As the size of imagery datasets and the number of uses grows, bandwidth is becoming a precious commodity. Even users in high bandwidth situations find themselves competing for available bandwidth, and so can benefit from JPIP. In scenarios where only a simple visual inspection is required, delivering the full image is no longer necessary. For example, a user may need to know if cloud cover in an image is over his area of interest. This case can be handled easily by JPIP streaming a low resolution, low quality region of interest from a centralized server to the user’s client application.
If the user needs more detail, he or she can simply zoom in to get more data, or image information, from the server. A similar scenario occurs when a user needs to do a quick inspection to make sure an image is suitable for an automated process like pan sharpening. This is an emerging use of JPIP technology, and systems that meet this need are being deployed today.
JPIP System Architecture. Systems using JPIP technology, such as Image Access Solutions (IAS) from Exelis Visual Information Solutions, are deployed in a client-server environment. The imagery is hosted at one or more server locations and cataloged so that users can discover it. The servers can be centralized with a single common catalog.
The servers can also be distributed such that different image sets are hosted on each server with a centralized, federated catalog used to provide searchable access to all of the images in the enterprise. When a client requests an image, it is streamed from the server where it is stored.
These deployment models remove the need to make multiple copies of the image data to be distributed to multiple servers. Imagery can be stored close to where it is collected and then streamed on-demand to a variety of end-user clients. Clients can range from lightweight Web-based viewers to desktop analysis applications or handheld mobile devices.
The requirements of disadvantaged users in bandwidth-limited environments drove early adoption of JPIP technology to support image delivery for imagery-based intelligence in mission-critical situations. JPIP is also providing users in the field with the ability to request on-demand imageryderived data products such as a target detection or disturbed earth indication. Even organizations with high bandwidth now are seeing the value of conserving that bandwidth with JPIP technology. In addition, compressing imagery to JPEG 2000 format conserves storage space, and the JPIP paradigm decreases the need to send multiple copies of imagery to distributed users.
Going forward, it will be interesting to watch how the uses and needs for this technology continue to evolve as our reliance on geospatial imagery for situational awareness grows. ♦
Kate Heightley is director of enterprise product management for Exelis Visual Information Solutions. IAS software from Exelis Visual Information Solutions was used to stream and view the imagery show in Figures 1-4.
