PapaJohn Productions

Newsletter #117 - Aug 19, 2006
'Blue-Screen' Your Own Outer Space Clips

Videos and stories about space travel and other worlds might be a passion or a passing interest. With the high resolution images and video clips available for download today, and the now easy-to-use 'blue-screening' feature of Movie Maker, it's fun and easy to make some neat space clips and to include in your home movies.
For telescopic views of outer space, go to Pictures from Hubble
And for views of earth from space, use Pictures and Animations of Earth from NASA
The Blue MarbleMost of these images and animations are free for open use.
Some Movie Maker users are busy trying to make custom XML effects which simulate space... maybe such effects are easier and better done by starting with real images. I downloaded a high definition 1280x720 pixel animation of earth, described on NASA's website as:
This spectacular “blue marble” image is the most detailed true-color image of the entire Earth to date. Using a collection of satellite-based observations, scientists and visualizers stitched together months of observations of the land surface, oceans, sea ice, and clouds into a seamless, true-color mosaic of every square kilometer (.386 square mile) of our planet. These images are freely available to educators, scientists, museums, and the public. This record includes preview images and links to full resolution versions up to 21,600 pixels across. 
Click the image of the blue marble to view it with a blue-screened overlying animation... it's a pretty crude spaceship, but it'll work for the tutorial. We'll use the same overlay in another clip as we walk through the steps it takes to make it.

SpaceHow can you use these pictures and animations? It's easy with Photo Story and Movie Maker. Here's another sample that takes two Hubble snapshots and overlays the spaceship, a small image from the clipart collection of Microsoft Office Publisher.
Outer Space - Sample
I'll take you through the steps to make this sample. Use similar steps with any of your own images as background, and any foreground overlay image.
... before getting into it further, a short note...


Vacation Corner...  this is it... we're in the bag-packing stage and turning full attention to our longest-ever vacation. I'm rounding up all the important stuff like cameras, tripods, monopod, tapes, batteries.... and a few other essentials. At this time next week we'll be in the Swiss Alps.
.... back to the main topic...

Making the sample blue-screened overlay clip
The approach is:
  1. Make animations of a couple Hubble space pictures with Photo Story 3.
  2. As the animations play in WMP on my laptop's LCD screen, test a camcorder special effect option named 'trail', which makes the moving stars more like shooting stars.
  3. Capture the recorded animations from the camcorder tape using Movie Maker
  4. Extract a cartoonish image of a space ship from a still picture using
  5. Animate the space ship using Rendersoft VRLM
  6. Use a custom xml file in Movie Maker to overlay the animated spaceship on the stories.
The route through the camcorder wasn't needed, and added complexity to making the sample... but I wanted to see how the camcorder special effect worked. It wasn't' great, but I consider it almost working OK!! The first part of the clip used it and the 2nd part didn't.
Let's go through the steps in detail.

Step 1 - Make animations of Hubble space pictures with Photo Story 3.
Here's the two images I used. The one at the right is Galaxy3000x1681 pixels, a picture named ssc2005-11a2.
And a larger 6000x4800 pixel image of the Whirlpool Galaxy (almost 30 megapixels) - below.
Whirlpool Galaxy
Two pictures for two Photo Stories to get two animated clips. I animated each by zooming into the bright centers.
They each use 45 seconds to zoom in. I tend to make the stories play slowly, as I can use the Speed Up - Double effect in Movie Maker if needed to speed them up. 
My personal preference about quality is to speed up a slow clip rather than slow down a fast one. But I don't have any authoritative references to support the point. 

Step 2 - Shoot the animations playing in WMP on the laptop LCD screen to test the camcorder special effect named 'trail', which makes the moving stars a tad like shooting stars.
The camcorder manual for my Sony TRV80 says the Trail effect "... can record a picture so that an incidental image like a trail is left...". We'll see what it does.
I put the camcorder on a tripod, played the two stories in WMP, and took videos... once without the special effect and once with it. It did a better job on the ssc2005 image than the whirlpool galaxy, so I included just that one in the final video. Check the stars in the first half of the sample video, especially those in the upper area of the frames. The effect does leave a bit of a trail, but it also adds a pulsation which I didn't like in the whirlpool galaxy. 

Step 3 - Capture the recorded animations from the camcorder tape using Movie Maker. This is a standard firewire connection capture from a mini-DV camcorder to a DV-AVI file. No further info is needed.

PublisherStep 4 - Extract a cartoonish image of a space ship from a still picture, using Make the background blue for the blue-screening in Movie Maker.
I searched for a space ship in Windows Publisher... a clip art one might be quicker and easier to extract from its background than from a real space ship picture.
Space Ship URL
I copied the image and worked it a bit in
... extracted the background by using the magic wand and the delete key
... made the background pure blue
... personalized it by adding my URL on the right wing
The edges ended up a bit ragged, but overall it was marginally good enough for a newsletter sample.
I saved the file as a BMP to bring into Rendersoft VRLM for animation.

Animate Space ShipStep 5 - Animate the space ship in Rendersoft VRLM, making the background blue for the 'bluescreening' video overlay.
This project was an easy one in Rendersoft. I didn't try to gauge the size of the working window as I knew Movie Maker would take the saved AVI file and stretch it as needed to fill the screen. I just eyeballed the working window to be sure it was wider than it was high.
I inserted a plain round disc shape, and colored it pure blue. The Red and Green sliders are at zero, and the Blue is at the full 255 position.
I colored the background pure blue - Blue=255. The picture shows the difference in blueness as the slider is being moved up to the full position, at which the color of the background matches the blueness of the disc perfectly for the 'blue screen' effect.
The animation starts the space ship off screen at the lower left, brings it in and moves it around, and then at some point (arbitrary) moves it quickly off into the far distance, toward the center of the window.
I made it to play for 1800 frames. The view here shows its position at frame #600. 1800 frames at 30 per second would be 60 seconds, enough to align with the combined photo stories.
I exported the project to an AVI file, using the Cinepak codec for compression. It's one of those that works well in Movie Maker.

Step 6 - Use a custom xml file in Movie Maker to overlay the animated spaceship on the animated background stories. This is a 'blue-screen' approach.
Finished VideoThe code for blue-screening that's been on this website page since we first issued it didn't work, so I updated the page to align with newer improved xml bluescreen code from the forums. The web page and this sample video now use these parameters.
<Param name="KeyType" value="1" />
<Param name="Similarity" value="100" />
<Param name="Progress" value="0.0" />
Don't use just these 3 lines, as the xml file won't work without the needed headers and footers from the other lines... get the full code from the website page.
The edges of the space ship are pretty jagged, and it's body pixilated. That's what happens when you start with a low resolution 168x262 pixel clipart image, and crop about a quarter of it to get the space ship. A higher quality image would do much better.
If you didn't look at the sample video on the way in, the image is also a link to it.

Conclusions and Closing
The subject matter of space isn't the important thing... it's being able to make animations from still images and combine them using a blue-screen approach.
Things moving in space tend to be in a linear path, so Photo Story and Rendersoft are well suited to making clips that look good. Other animation subjects that move in curves, like many things here on earth, would need other software such as Adobe Premiere to do them well. 
The reason the older code for blue-screening didn't work has to do with the exact color of blue being used. The new code is much more tolerant of differences, and works well.  

This is it for a while, as we leave for Europe on Thursday. I'll publish the next newsletter toward the end of September.

Have a great week...