Space Image Processing Classes are Go!
Posted by Emily Lakdawalla
2009/11/06 04:14 CST
I got a huge response from readers interested in me conducting some online classes on space image data -- how to access and process it. Some of you are interested just in being armchair explorers, but I also received a surprising number of responses from college and graduate students who are looking for some introductory material on image processing to help them in their fields of study. So I am going to go forward with conducting these classes and do my best to help you all out!
Many people expressed interest in being able to download and view the classes as videos rather than tuning in live. After some experimentation, I've decided that the best way for me to do this is to conduct the classes using WebEx. People who want to tune in live may do so; after the live class, I'll make a video version available within a couple of hours. The video version may be viewed as a stream or downloaded. This has numerous advantages over Ustream, but in order to view a downloaded video it does require viewers to download and install some free software to enable them to watch the WebEx recording. (I believe you don't need to install the software if you just watch it as a stream, but I'm not sure.)
Many people also urged me to teach the use of free software for the image processing. So I'm going to go with GIMP, which should work across all platforms, and is similar enough to Photoshop that I am not having too much trouble finding my way around. Having said that, if anyone out there can coach me through working with 16-bit PNG images, I'd really appreciate it; I thought GIMP was supposed to be able to support higher than 8-bit depth now but although I've found it can open a 16-bit PNG it converts it down to 8-bit as it does so, which isn't helpful.
The first two classes will be:I. Images Are Data, tentatively scheduled for Friday, November 13, 2009 at 10:30 Pacific (18:30 UTC). In this session you'll learn to look at images differently -- not as snapshots of objects, but as scientific data. We'll cover some very basic image processing techniques (brightness and contrast adjustment and other ways to monkey with an image's histogram), which I'll explain in terms of how they manipulate the underlying data. Even if you're quite comfortable with such basic image adjustments, I encourage you to follow along with this class or at least download and read the slide set, as it'll be important to shift your way of thinking about images to a more quantitative, scientific viewpoint.II. Getting Started with Space Image Data: Rover and Cassini Raw Images, tentatively scheduled for Thursday, November 19, 2009 at 10:30 Pacific (18:30 UTC). We'll dip into the two most accessible catalogs of images, the "raw images" from the Mars Exploration Rovers and the Cassini orbiter. I'll show you how to locate interesting images and do some basic processing, including but perhaps not limited to: level adjustment; making RGB color images; making 3D anaglyphs; and making animations. Then I'll explain the drawbacks of working with these raw images and why you should want to dig deeper!
I will follow these with classes giving some more detailed background on how space cameras work and introducing the Planetary Data System, and (if people are excited about the idea) I may get in to some special cases of how to access and process data from specific missions, but these won't happen until after the Thanksgiving holiday, which is November 26.
If you want to watch the first class live, you must send me an email (to blog at planetary dot org) so that I can put you on the invitation list for the WebEx session. Our WebEx account limits us to 25 live attendees. I don't think this will be a problem, but I ask you only to request the login information if you are reasonably certain that you will be able to attend live. If I am overwhelmed with requests, I can schedule a second session of the same class. Once the class is over, I'll post information in the blog about how to download and view the archived version; there's no limit to how many people can do that.
Also, if you do not currently use GIMP, you should install it on your computer and play with it a little bit to achieve basic comfort with file operations (new, open, save, save as) and to fiddle with the tools so they're not utterly foreign to you when I start the class.
Finally, a plea. I am doing these classes because I am passionate about the exploration of our solar system by robotic spacecraft, and I want to help more people gain access to the fruits of these robots' labors. But it is a lot of effort for me to put this together. I'm not going to charge anyone anything to view the classes, but I will ask you to consider making a donation to The Planetary Society for whatever you think they are worth to you, up to what you can afford. (Note: the form that link gets you to has generic language on it, but you can see that "blog" is mentioned in the URL; I can assure you that the bean-counters here at the Society will know that it's my work you're supporting if you donate through that link. :)
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