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.
Most 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.
How 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.
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...
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:
-
Make animations of a couple Hubble
space pictures with Photo Story 3.
-
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.
-
Capture the recorded animations
from the camcorder tape using Movie Maker
-
Extract a cartoonish image of a
space ship from a still picture using Paint.net
-
-
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 
3000x1681 pixels, a picture named ssc2005-11a2.
And a larger 6000x4800 pixel
image of the Whirlpool Galaxy (almost 30 megapixels) - below.
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.
Step 4 - Extract a cartoonish
image of a space ship from a still picture, using
Paint.net. 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.
I copied the image and worked it a
bit in Paint.net...
... 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.
Step 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.
The 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...
PapaJohn
