I usually reserve these kinds of things for a quick tweet or Facebook post but I figured it was time I actually explained the creation of these particular videos. Shown below for your viewing pleasure is yet another Curiosity descent video that makes for some incredible watching:
For starters the first thing I’ll let you in on is that all the sound you hear in this video is 100% fake as Curiosity does not have a microphone on board. That may seem strange, I mean what camera that can take video doesn’t have one, but they’ve launched craft to Mars with microphones before (the Mars Polar Lander was one, although it was tragically lost, with the Phoenix Lander being one that actually made it) and the recordings made back then weren’t particularly interesting. Most of the noise that they recorded was akin to static and really didn’t have much use scientifically so future Mars craft like Curiosity don’t carry them so they can use the payload space for more experiments. Additionally the actual sound would probably be a lot more harsh (ever heard a microphone in high wind?) as at this stage Curiosity was rocketing towards Mars at a pretty decent rate.
The original video, shown here, is based off the images from the MARDI camera that’s on the bottom of the rover specifically for this purpose. Now I’ve heard differing reports as to what the actual frame rate was as the original video says it’s somewhere on the order of 2 FPS (297 images over 150 seconds) but most are quote as saying its 4FPS. The imager itself is capable of doing up to 10FPS but I don’t believe it was for this particular video. How then, you might be wondering, do they manage to get something like 20 FPS like the video does above? Well the original video is probably the best candidate for something called Video Interpolation (or inbetweening as its usually referred to).
In essence the additional frames are generated from the frames either side of it and the algorithms are essentially guessing what’s going to come next. For the MARDI images this works quite well as the amount of change between frames is quite low and thus the interpolation between frames looks quite good. Most of the better ones of these also have a lot of hand work with them as well to smooth out some things (like the heat shield falling motion). If there’s a lot of action between frames you tend to get smudging which you can actually see hints of in the video (look at the landscape shifting about as it gets closer). It works on any kind of video too and a lot of enterprising YouTubers use it in order to get that slow motion effect without having to spend the untold thousands on high speed video cameras.
I find the videos interesting both because of what they are (technical achievements in both their creation and interpolation) and what they represent to us as species. The response to the Curiosity videos has been nothing short of amazing and it makes me so happy to see so many being inspired by it. It’s things like this that spur on the next generation to become the kinds of people capable of making things like this and it never fails to impress me time and time again.