Video Keystone Correction - Help
This is a discussion on Video Keystone Correction - Help ; First off apologies for being a newb, I've not really used Linux for
long but this problem is really bugging me and despite loads of
searches I've not managed to find any info on what I'm trying to do
(guess ...
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Video Keystone Correction
First off apologies for being a newb, I've not really used Linux for
long but this problem is really bugging me and despite loads of
searches I've not managed to find any info on what I'm trying to do
(guess I've been looking in the wrong places).
I have a comp with Fedora Core 2 installed, it sits in the living room
and acts as a video recorder / media player / internet server for the
rest of the house. Recently I've plugged a video projector into the
second head of the Matrox G400 card (in a true home cinema style),
however due to the angle it projects at there is a lot of keystone \=/
on the image. I can partially correct this from the projector by
playing with the lenses, however beyond a certain point it is
impossible to keep the entire projected image in focus. Unfortunately
the LCD panel in the projector has no way of correcting this further
(i.e. the driver board doesn't support keystone correction)
What I'm looking for is a way through software on the computer to
shrink the top of the image whilst leaving the bottom untouched (into
a trapezium shape) to completely correct the keystone. I realise that
I'll be losing pixels on the LCD by doing this, however that's an
acceptable loss for a rectangular image!
The Gfx card drivers for Linux don't seem to have anything to do this
(while a lot of windows drivers seem to have this as standard), and as
of yet I've not found any alternative way of doing it - any
suggestions?
Thanks in advance,
Steve
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Re: Video Keystone Correction
Steve wrote:
> First off apologies for being a newb, I've not really used Linux for
> long but this problem is really bugging me and despite loads of
> searches I've not managed to find any info on what I'm trying to do
> (guess I've been looking in the wrong places).
>
> I have a comp with Fedora Core 2 installed, it sits in the living room
> and acts as a video recorder / media player / internet server for the
> rest of the house. Recently I've plugged a video projector into the
> second head of the Matrox G400 card (in a true home cinema style),
> however due to the angle it projects at there is a lot of keystone \=/
> on the image. I can partially correct this from the projector by
> playing with the lenses, however beyond a certain point it is
> impossible to keep the entire projected image in focus. Unfortunately
> the LCD panel in the projector has no way of correcting this further
> (i.e. the driver board doesn't support keystone correction)
>
> What I'm looking for is a way through software on the computer to
> shrink the top of the image whilst leaving the bottom untouched (into
> a trapezium shape) to completely correct the keystone. I realise that
> I'll be losing pixels on the LCD by doing this, however that's an
> acceptable loss for a rectangular image!
>
> The Gfx card drivers for Linux don't seem to have anything to do this
> (while a lot of windows drivers seem to have this as standard), and as
> of yet I've not found any alternative way of doing it - any
> suggestions?
>
> Thanks in advance,
>
> Steve
I don't remember keystone corrections for *any* graphics
card as standard. Damn difficult to synthesize
video waveforms to do that!!!
You need to mount the project further high up and
project it properly, or tilt the screen to match
the projection angle.