Nonred key transition problem

[Martini]

Hello,

I am confused beyond limits... I try to make a key
transition of one video over another to work. I have
created a custom transition:

----------------
<TransitionsAndEffects Version="1.0">
<Transitions>
<TransitionDLL guid="{C5B19592-145E-11D3-9F04-
006008039E37}">
<Transition name="Key_Nonred_100" iconid="91">
<Param name="KeyType" value="1"/>
<Param name="Similarity" value="100"/>
</Transition>
</TransitionDLL>
</Transitions>
</TransitionsAndEffects>
----------------


I am trying to achieve an effect of overlaying the video
shot against a blue(ish) backdrop over another video. It
basically works fine, but during the transition the key
seems to "fade out", making the blue backdrop of video B
more visible to the end of the transition.

Strange thing is that if the second clip is a still
picture with backdrop color of 0000FF the transition
works OK for whole duration.

The example can be seen in (quite horrible test movie)
http://www.gate.ee/stuff/keymovie.wmv (473kb). Both
transitions are done with abovementioned custom
transition, but only still image works the way I want it
to.

What's up? What am I doing wrong?

 

[PapaJohn \(MVP\)]

I think it has to do with how pure the blue color is... as the transition
works with a single color value, not with a range of them.

PapaJohn

 

[Martini]

I would accept that explanation if I would use the
KeyType 0 (chroma) instead of KeyType 1 (nonred) I am
using in my transition. Nonred should replace all green
or blue backgrounds. Funny thing is that it does exactly
that at the start of the clip but not at the end. The
whole clip I am trying to overlay is shot without moving
the camera or changing the lighting so the blue
background stays pretty much the same during the clip.

 

[PapaJohn]

I agree with you.
--
PapaJohn
www.papajohn.org

I would accept that explanation if I would use the
KeyType 0 (chroma) instead of KeyType 1 (nonred) I am
using in my transition. Nonred should replace all green
or blue backgrounds. Funny thing is that it does exactly
that at the start of the clip but not at the end. The
whole clip I am trying to overlay is shot without moving
the camera or changing the lighting so the blue
background stays pretty much the same during the clip.