Hi Gene

Hi Gene,
    I could not find your original post on perspective so I am posting my 
comments in a new thread.
a).  There is nothing wrong with the perspective of your image.  However, it 
can be changed so that it appears that it was taken from a  more pleasing 
position.
b).   The perspective changes I made are for the simple case of looking 
directly at a flat building from a "reasonable" distance away.
c).  This is what I did

1.  Upsample until your computer can barely handle the file size. 
Perspective manipulations are very destructive to quality.
2.  Get rid of distracting elements.  This led to the figure on the left. 
It's already a big improvement over the original.
3.   Create a layer from the original so that you do not destroy the 
original.  Also some graphics editors only allow you to distort a layer.
4.  Rotate the image so that some portion at or near the center of the image 
is vertical.  This is where your camera would be pointing.
5.   Use whatever tool is available which can individually move a corner of 
the layer.  PSP XI calls this a perspective correction mode.  Photopaint 
calls it the distort mode.
6.    Move a top corner so that the side of the building has a slight tilt 
towards the center.  The greater the tilt, the greater the illusion of 
looking upwards.
7.   Repeat for the other side.  The tilts of the sides should be such that 
they would meet at a "vanishing" point directly above the vertical
center 
line if they were extended.
8.  Move the same corners so that horizontal elements in the picture are 
shown horizontally.
9.   Repeat everything to get the vertical center to be vertical, horizontal 
elements to be horizontal,  and the sides to be tilted and converge directly 
above the center line.

    At this point, the perspective for a flat, head on view is
"correct". 
However, a final trim is usually necessary to get the aspect ratio where you 
want it.  Use the basic transform mode to pull the sides in or out.

   After this, life gets complicated in a hurry.  If the sides of the 
building are showing, horizontal lines must converge to either side to new 
vanishing points on the horizon.  How do you handle, objects above and below 
the horizon.  What if the camera is  pointing upwards.  For that matter, 
what is the horizon.  Read all about it in the first chapter or two in a 
book on perspective.
Phil 

"Philip K" <PhilipK@aol/com> wrote in message
news:4806d7ad_3@cnews...
> Hi Gene,
>    I could not find your original post on perspective so I am posting my
> comments in a new thread.
> a).  There is nothing wrong with the perspective of your image.  However, 
> it
> can be changed so that it appears that it was taken from a  more pleasing
> position.
> b).   The perspective changes I made are for the simple case of looking
> directly at a flat building from a "reasonable" distance away.
> c).  This is what I did
>
> 1.  Upsample until your computer can barely handle the file size.
> Perspective manipulations are very destructive to quality.
> 2.  Get rid of distracting elements.  This led to the figure on the left.
> It's already a big improvement over the original.
> 3.   Create a layer from the original so that you do not destroy the
> original.  Also some graphics editors only allow you to distort a layer.
> 4.  Rotate the image so that some portion at or near the center of the 
> image
> is vertical.  This is where your camera would be pointing.
> 5.   Use whatever tool is available which can individually move a corner 
> of
> the layer.  PSP XI calls this a perspective correction mode.  Photopaint
> calls it the distort mode.
> 6.    Move a top corner so that the side of the building has a slight tilt
> towards the center.  The greater the tilt, the greater the illusion of
> looking upwards.
> 7.   Repeat for the other side.  The tilts of the sides should be such 
> that
> they would meet at a "vanishing" point directly above the
vertical center
> line if they were extended.
> 8.  Move the same corners so that horizontal elements in the picture are
> shown horizontally.
> 9.   Repeat everything to get the vertical center to be vertical, 
> horizontal
> elements to be horizontal,  and the sides to be tilted and converge 
> directly
> above the center line.
>
>    At this point, the perspective for a flat, head on view is
"correct".
> However, a final trim is usually necessary to get the aspect ratio where 
> you
> want it.  Use the basic transform mode to pull the sides in or out.
>
>   After this, life gets complicated in a hurry.  If the sides of the
> building are showing, horizontal lines must converge to either side to new
> vanishing points on the horizon.  How do you handle, objects above and 
> below
> the horizon.  What if the camera is  pointing upwards.  For that matter,
> what is the horizon.  Read all about it in the first chapter or two in a
> book on perspective.
> Phil
>

That's interesting, Phil.
And effective.
-- 
Tadjio