Eric Hartwell's InfoDabble

Dust Devil Dance

Fri, 12 Aug 2005 15:16:56 GMT

I don't know how they do it, but the JPL Mars Rover team just keeps getting better at capturing images of dust devils from Spirit's perch high up on Husband Hill. I've created an animation from the original images (Spirit Sol 568 - August 8, 2005). This image is half-sized; Click here for the full-sized animated GIF (800K).

Update: The original photos were taken at roughly 30 second intervals. The animation uses the raw, unprocessed images without any contrast enhancement.

Opportunity Rover Begins Escape From Sand Trap

Sun, 15 May 2005 01:29:34 GMT

[JPL Mars Rovers sol 464, 5/14/2005] Careful Rollout: The Mars Rover Opportunity rotated its wheels on sol 463 for the first time since it dug itself into a sand dune. The wheels made about two and a half rotations. In the loose footing, the rover advanced 1.1 inch forward, 0.19 inch sideways and 0.18 inch downward. The results were a good match for what was expected from tests under simulated Mars conditions on Earth, and the rover team will decide whether to repeat the same careful movement again in two days. Two weeks ago, Opportunity had completed nearly 131 feet of a planned 295-foot drive, when it started slip on a one foot tall by 8 feet wide sand dune. Its wheels kept rotating, but the rover barely inched forward. The rover team spent more than two weeks designing and conducting tests before choosing the best way for Opportunity to drive out of the dune. [Thumbnail links to 1,436K animated GIF]

How to make screen capture work with Windows video

Wed, 04 May 2005 13:49:27 GMT

Most people know that when you press the Windows Print Screen (PrtSc) key, nothing (apparently) happens. Some people know that Windows actually takes a snapshot of your computer's screen and copies it into the clipboard, so you can paste it into your favorite graphics processing program, or Paint. A few people even know that pressing Alt+PrtSc copies the currently selected window instead of the full screen. Of course, there are all kinds of screen capture programs to give you more control over the process.

In theory, it should be easy to capture stills from video files, whether paused or streaming, by pressing Atl+PrtSc and pasting the result into your graphics program. However, quite often all you get is a beautiful image of the media player's border and controls, with a blank where the picture of the video is supposed to be.

I always thought this was some sort of DRM control "feature", but I was wrong. It's actually caused by your video acceleration setting.

D'Oh!

In Fixing a blank display, the screen capture experts at PixelMetrics explain how to turn off the media player's acceleration while recording. They give instructions for Media Player (7,8,9,10), QuickTime Player, RealPlayer, and WinAmp.

If that doesn't work, they also explain how to disable hardware acceleration system-wide.

An end to those annoying support phone calls ...

Sun, 01 May 2005 19:18:22 GMT

"Tired of Supporting Friends' Computers? Migrate Them to GNU/Linux". [NewsForge 4/30/2005 via Linux Today 5/1/2005] This article actually makes a certain amount of sense, at least from the viewpoint of the unpaid support person. As long as you understand it's really talking about locked-down systems, not Linux.

"The result, after six months, is an end to the annoying phone calls ... Yes, they're all still using GNU/Linux. It's what they imagined computing would be in the first place -- no hassles, no threats, no worries. It's like a dream come true, not just for them, but for me too -- no more troubleshooting nightmares and monthly service calls."

Of course, while a static system may be "a dream come true" for support, it may be a different kind of dream for a user who wants to use a new game, camera, or file format ....

"GNU/Linux does not pose the kinds of problems that Windows does. There is no registry to easily corrupt, and the operating system does not fail in generic, catch-all ways. The user has no power to alter the system software, so important files are not accidentally deleted, and potential viruses and spyware programs have no ability to wreck the system."

It's true that Linux currently has fewer installations and fewer attackers, but both of those statistics are changing. As a direct result of Linux's increasing popularity, more and more malware writers are targeting Linux systems -- after all, you're guaranteed that each target system has at least minimal compile/link/load support and scripting, not to mention rootkit support. Security through obscurity is a fool's game.

The point about protecting the system software from the user is an excellent one, though. I wonder if the author has ever heard of Windows XP?

"It takes a knowledgeable, skilled user to keep a Windows system properly maintained. In short, they need an operating system that, for all their trying, they cannot screw up. Windows isn't it."

Mind you, as long as the users are unable to change the operating system, add or remove software, or add or remove hardware, you have an appliance computer. The underlying operating system is almost irrelevant, but in practice it makes much more sense to run a locked down Windows XP installation running in User mode. Windows XP's autoupdate and autorepair mean that with a properly configured antivirus program the system will maintain itself with NO user effort.

Of course, it's not even that simple. I configured a fully locked-down XP system so my mother could use email and browse the web. This worked extremely well for her, but it drove my father nuts. He couldn't change any of the desktop settings, let alone "clean up" the system by moving all the DLLs to the same directory, installing the "right" applications, and deleting "problem" files like kernel32.dll. He finally lost patience, wiped the system, and installed his own highly "optimized" version of Windows 98. He'd probably have done the same thing to Linux. He's happy, she's thrilled any time her email works, and I stopped taking support calls -- so, I guess, that approach works, too.