#Key color thingy
8 messages in this thread
GreG, about a million years ago, Blaq! was having a conversation with Mike H.
about Impulse having removed the ability to specify a key color. I think 8^)
.???
What I'm trying to do, for example, is the following:
I've got your blinking dino (the cute one) and I am trying to composite a
background.
The backgound is also a 39 frame .flc, it has lightening and a mirrored
reflection of the dino head in a rippling pool (nifty <g>). Gracias el
WinImages/FX.
I'm using AAPro for composing but could also use WinImages.
Now the problem … I run in to it often:
The top of your dino's head is black (0,0,0), as are parts of his eye and
earhole. They match the black (0,0,0) background so my composite shows thru
these areas.
What do you do in these instances? Does my explanation make sense? Do you
make a mask? If so, how <g>? What the heck is this Alpha stuff anyway?
Micahel B.
Key color thingy is just that, you specify a color that will be used for
replacing it with another image/animation. If I had intended to do
compositing, I would have rendered the animation against a unique color…one
that was not part of the dino object.
I don't know how AAPro works, but with WinImages you can create a mask using
the magic wand function to isolate the black background. You may need to edit
the mask a bit, but you can add/subtract from it as you need. Not having used
WinImages extensively for compositing, I can't tell you from memory how to do
this. Give it a shot and see how it goes.
I think what Blaq! was referring to was something specific to the amiga, where
on the Amiga, color register ZERO is treated as a transparent color (doesn't
matter what the value of the color is..just the register location).
>> What the heck is this Alpha stuff anyway?
With 32bit images, an 8bit image mask is tacked onto a 24bit image to define
different levels of transparency for the 24bit image data. Thats the condensed
description of what it is. <g>
-GreG
<<I would have rendered the animation against a unique color…one that was not
part <<of the dino object.
Heck, I never thought of that. Yup, I guess a bright red background would have
worked nicely.
I'll try it in the future.
Thanks GreG
Michael B.
Michael,
> Now the problem … I run in to it often:
> The top of your dino's head is black (0,0,0), as are parts of his eye and
earhole.
> They match the black (0,0,0) background so my composite shows thru these
areas.
WinImages F/x can fix this using Alpha compositing, I suspect. You need to make
an alpha channel for the dino that passes the dinosaur and not the background.
WinImages F/x will let you edit the alpha channel separately, so if the alpha
channel is generated with holes as you describe, you can edit them and *then*
composite, which will fix the problem 100%.
> What the heck is this Alpha stuff anyway?
An alpha channel is a set of data attached to an image which provides a
transparency level for every pixel in the image. This is usually done by adding
an additional 8-bit (256 grey level) pixel for every pixel in the image, where
black means transparent (or not) and white means the opposite of black… grey
levels indicate partial transparency, which also has its uses of course.
An alpha channel can be generated by color keying, by hand, or a combination of
the two. WinImages F/x will let you do just about anything you want to an alpha
channel, so there should be no problem getting all this to work.
Good luck!
Ben Williams
for Black Belt Systems
Cool! How's the Imagine-ing coming, Bem? 🙂
I've not had much time to work with it; I want to, but it's pretty arcane. 🙂
I'll figure it out.
Ben
If I can get good results from it, anybody can 🙂
good luck.
PS… btw, I think I figured out the custom gadget button things like you had
in WinImages. 🙂
<<WinImages F/x will let you do just about anything you want to an alpha
channel, <<so there should be no problem getting all this to work.
Thanks Ben, I'll give it a bash!
Oh, and WinImages is a great program. After doing some of the tutorials, it
took me a *long* hour to get used to working with video sequences in the time
line. But now things are starting to fly! I even motion-blurred an
animation, as you suggested in a different thread. Setting up FX on video
sequences only takes a few minutes now.
Unfortunately my priorities are mixed up and I've been spending too much time
working (ugh) and not enough time learning. Had to print some of the Help
files to read on the toilet … it was my only spare time.
Michael B.