The IAS Viewer is our preferred tool for looking at HiRISE images in full resolution. It provides excellent support for the JP2 file format and the interactive streaming protocol for JP2 which is called JPIP. It is written in Java and installs automatically in a secure “sandbox” on your computer when you visit a link to it. These links are in a section labeled “JP2 Quicklook (IAS Viewer)” on the HiRISE web site; every observation will have that on the right-hand side of the page.

We use the IAS Viewer ourselves in most cases. A prerequisite is having Java installed already on your computer; I’m pretty sure that both Microsoft Vista and Apple’s OS X do that by default, and most older versions of those operating systems do too. You can check by going to java.com and clicking on the “Do I Have Java?” link.

I have tested the IAS Viewer on a 2001-era computer (an iMac DV) with a low-speed wireless connection. Surprisingly, it worked about as good as on our work machines (dual or quad-core Macs with gigs of memory and ultra-fast Ethernet connections to nearby servers). With much older PC’s or via dial-up it may not be usable, I expect. But the bottom line is, you do not need to have the latest and greatest in computing technology to fill your screen with a steady source of high-res HiRISE pixels.

Early in the mission, our partners at NASA Ames put together a site using a Flash applet called Zoomify. They still maintain this site; however, it takes time and effort for them to keep up with our releases. Zoomify uses “tile pyramids”, or multiple copies of image data at each zoom resolution. So not only must the data be transferred, it must then be rendered into many tiles, occupying slightly more space than the original data. For that reason, they convert to JPEG, which eliminates some of the highest resolution information. Still, it may be faster because the lower resolutions are pre-rendered and the highest resolution has been decreased. Flash, like the IAS Viewer, is supported on Windows, Mac, and (x86 flavors of) Linux.

(more…)