Suggestion for Next Release - Electronic Keystone Correction

  • Thread starter Thread starter Greg Glynn
  • Start date Start date
G

Greg Glynn

I don't know if the developer will read this, but I think
it's an idea worth mentioning.

Some older style data projectors (and some newer, less-
expensive onces) don't have keystone correction.

Why not have the ability to do SOFTWARE keystone
correction in a Powerpoint program.

The PGUP and PGDN keys could be used during a presentation
to do correction.

I think it would be a worthwhile addition and probably
reasonably easy to code.

Greg Glynn
 
Interesting idea Greg, a projector set-up function. Wasn't there something
like that in PowerPoint 95?

There are some issues with software keystone correction in general that
would need to be addressed.
Resolution and anti-aliasing will become considerable problems. For
instance, a picture that has 1024 pixels across, will loose a lot of its
sharpness if compressed into 1012 pixels. (In most cases it would look
clearer if cropped by 12 pixels than if compressed by 12.) I know that some
projectors already use software keystone correction, and I do not know how
they have addressed this issue. I suspect they haven't.
Also, lines or letters that span across a resolution change (each line where
one less pixel is used) would appear jagged or offset by a little.

The solution to this jaggedness is to use a higher screen resolution to make
each of the changes less noticeable. But it has been my experience that
projectors with higher resolutions tend to include screen adjustments like
keystone correction.

So it becomes a catch-22 type of situation. The high-end projectors that
don't need it could use it; and those that do need it , won't have good
results.


Perhaps, if the hall and set-up are known, you could set-up your master with
the 'keystone correction' built in. Have black triangles on either side
with the base in the upper outside corners. Then as you build the show
allow for print at the top to be enlarged (as titles usually are) by
projector distortion.

I know this is not a good solution, but it's a little less expensive that
upgrading the projector.

B
 
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