|
Because equirectangular images are quite distorted at the
top and bottom of the image, it is unwise to attempt to edit the image in
these regions. I try to keep all of my editing to the central 1/3 of
the image. To edit the zenith and nadir sections then, it is necessary
to change the orientation of the panorama. I do this in two steps.
-
Extract a view with a pitch of 90°. This places the zenith
at the centre of the image and the nadir at the lateral edges.
-
Offset the image horizontally by 25%. This moves the nadir
away from the edge making it easy to edit both the zenith and nadir at the
same time.
Extract a view with a pitch of 90° (Filter >
Panorama Tools > Adjust)
Set the Options
-
Both Image and Panorama have the same HFOV, Width,
Height and Format.
-
Set the Pitch to 90°
-
All other options are irrelevant here
Select OK and then check the Prefs
Since both the Image and Panorama are the same size we don't need to save
the result to another file so only (a) is needed.
Set More Preferences
Set the interpolation options to the highest quality.
Do this for each of the layers and then offset each layer by
25%. (e.g. in this case 250 pixels) This produces two layers
that look something like this.
To apply the patch...
-
From the patch layer, select a region to of image to use
as a patch and copy it to a new layer. Repeat for the nadir.
-
Hide the full patch layer and make the new patch section
semi transparent so that you can see how well they overlap the main
panorama below.
-
Distort each section to fit. N.B. you will probably not be
able to get a perfect fit. Look for a "band" of close fit around the area
that requires patching. This can take a lot of practice and
patience.
-
Manually edit the layer with a seam around this "band" of
close fit.
-
Remove the transparency
-
Check the colour balance between the patch sections and
the main panorama and edit if necessary... particularly the nadir section
which often has a higher contrast due to a lesser degree of lens flare.
-
Flatten the image.
-
Offset the image -25%
-
Insert a view of the panorama with a pitch of 90°.
Since all of the settings are the same as used above, all you have to do
is select "Insert" instead of "Extract"
And so we have the completed panorama.
Now that you've finally read this far... if you want the
source files used in this section of the tutorial you can
download them here (6Mb). This file includes
the source images, the final script and a Photoshop document of the panorama
prior to applying the zenith/nadir patches. |