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Howdo all, yep that time has come for another blog entry, something that's a bit of fun.. Green Screening.
For those of you that are wondering what Green Screening (also known as Chroma keying) is, it's a simple technique for making you appear somewhere your not on video.
Anyone who has seen a weather forecast or a new's show on TV will have seen green screening in action... Or not as you can't see the green screen once the editing has been done..
Anyway, here's what a green screen looks like.. Or part of it as it is rather big being 3m x 1.6m.
Ideally your screen should hang nice and flat with no creases showing... My screen was quickly hung in a way too small room just so I could have a quick play.. I've not told my wife yet that I want to turn the spare bedroom into a recording studio yet
So having filmed your bit of footage, you now need to do some editing.. I use Sony Vegas Pro 11 for all my video edit (more about Vegas in a later blog entry), as you can do so much in it.
If we zoom in a bit you can see me and the bit of backing footage I'm going to use in the time lines.
You need to make sure your backing footage is below the green screen footage or this won't work.
Now to add the "effect" which will make the green screen vanish.
In Sony Vegas I click on the "Video FX" tab which brings up a whole host of video effects options.. Chroma Keyer is the one we want.
As you can see you do get a choice of different types of Chroma Keying, you can do it using a red or blue screen, but green works the best which is where "green screening" got it's name I guess.
The last 3 GS options are my own custom pre-sets.
For this demo I dragged and dropped the "GS option" onto my GS bit of footage in the timeline.
Which gives you this. The GS has vanished and been replaced by your bit of backing footage.. It's not looking that good however, the backing is a bit dark and you can see the folds in my GS (which is why you need them as smooth as possible).
When you drag the GS option from the Video FX tab onto your GS footage this window also appears so you can tweak the GS effect.
You need to tweak the Low threshold and High threshold a bit, I also add a very small amount of blur..
Until you end up with something like this.
A close up..
So there you go, my short guide to Green Screening..
If your wondering why this blog entry is called "A stupid guide to Green Screening", this short video will give you an idea of what's possible..
The only limit is your imagination
After leaving the hospital, the endless doctors appointments began. Primary concern was the facial fractures which needed to be surgically repaired before the bones fused incorrectly. Second is the damage to the nerves controlling my left eye. My eye was able to look right, but there was no signal to move my eye left which resulted in double vision. It was also the same side where my face was paralyzed so not only could it not move properly, the eyelid wouldn't close either.
After a 3 1/2 hour surgery, metal plates and screws placed in my face aligned the bones back to where they're supposed to be. The skull fractures were fusing perfectly, or close to it anyway. I still had considerable numbness on the right side where the surgery was, as well as swelling.
During the first month of recovery, I didn't notice much improvement. Still had double vision and even though the surgery was successful, the swelling and bruising made me look very poor. My facial paralysis was not improving and in fact, there is now a noticeable drooping on the left side due to the lack of muscle movement. Electrical stimulus tests showed that the nerve wasn't severed, but was damaged and recovery would be long. There was talk of decompression surgery, but the neurosurgeon didn't think that it would be as beneficial as they could have hoped.
The second month, I began to notice that my double vision was lessening. If I looked to the right, I could see a single image. This was terrific news because it meant that the nerve was healing and there's a strong likelihood that my vision will return to normal. Not much on the facial movement, but the swelling had gone down and I was beginning to look somewhat normal once again.
During the subsequent months, my vision was finally returned (month 4) swelling was gone (month 6) and my face was showing the beginning signs of moving once again. While still mostly paralyzed, there is not quite a bit of movement and best of all I can close my left eye. I wouldn't say that I can blink, but it is a significant improvement from before. While I am still not a good looking guy, if you didn't know that I was run over by a truck, you really couldn't tell by looking at me. There are some indications that I'm not quite right (visually ) but for the most part, I have regained muscle tone in my face.
I have a long way to go, measured in months to years, but I am alive and functioning. Every day I am feeling a little more like my old self and I am thrilled at the outlook.
That's all for now...