polishing up panoramic (panotools/ptgui) pictures?

Hi, I have been playing around with panotools and ptgui trying to make
some good panoramic pictures and have run into a few problems that may
or may not be fixable. I have a picture (well a few but the following
is the best example) where the different pictures used to put it
together are of slightly different light and/or focus, I posted it
(having used enblend and w/o) so you can see what I mean:
http://www.geocities.com/gaikokujin_kyofusho/pictures/vangvieng.jpg

and another picture is (to me) almost perfect except for one part where
some ripples in the water are really obvious (this isn't the whole
panoramic but I didn't see the need to post the whole thing):
http://www.geocities.com/gaikokujin_kyofusho/pictures/mekong.jpg

I am using photoshop CS (and have gimp too) and was hoping some people
out there might have some suggestions on how I could salvage/repair
these pictures. Any help would be greatly appreciated.

Cheers

-Gaiko

 

Sorry I can't offer a specific remedy, but I can give a tip: when doing
multiple panoramic exposures, lock the exposure and focus. Auto-anything can
really mess up the outcome.

 

You may be able to open each picture separately and apply auto Levels,
Contrast and Color (Image > Adjustments) and then reassemble them.
Currently, the differences are quite pronounced. Or you may be able to do
the same thing to the panorama, but with lightly feathered selections.
Adjusting them first, prior to assembly would be a good idea. But Like JJ
said, you should've shot everything with the exact same settings in the
first place.


Peadge

 

Clone tool for the water?

The first one, I hope is still in separate layers. You can use the dodge
& burn tools with low opacity & a big soft brush. The smudge tool is
good for blending simple skys sometimes.

 

I have had some success with processing each picture to get an average
brightness/contrast, and then putting them back into the panorama. As
for the problem with the ripples, I see no workable solution. You might
try a slight blur over the conflicting area to minimize the effect.

 

Oh, for the ripple problem, which I forgot to address earlier, you may be
able to make a heavily feathered selection of some other ripples and copy
and paste it into a new layer on top. Then use your eraser tool with a large
soft brush and the opacity turned down to about 40% or so to erase the edges
to get it to blend even more. Or you may add your own ripples to it using
the Distort Filter.

Peadge

 

Thanks for everyones comments. I will try some of the suggestions. As
for locking the exposure and focus i am not sure my camera can do that
(I have a dinky DiMAGE Xt), but if i am wrong (and i could be, I could
have been missing the obvious) please let me know.

Cheers (and thanks)

-Gaiko

 

jjs wrote

Agreed. Start with what will be the brightest part of the mosaic. Focus
manually, and set the exposure manually to the maximum possible which
doesn't lose important highlights. Use these settings for every panel.
If a darker panel contains important highlights you may need to reduce
the overall exposure.

 

Or use a layer mask, selecting only the overlapping part of the image.

 

Ripples not too difficult at all if you have enough overlap to blend
them in. See Peadge's reply above.

 

Be sure to turn OFF automatic white balance.
Canon Photostich can deal with exposure differences
but not color differences.

As for ripples in the water ... just make time stand still.

Chuck Forsberg www.omen.com 503-614-0430
Developer of Industrial ZMODEM(Tm) for Embedded Applications
Omen Technology Inc "The High Reliability Software"
10255 NW Old Cornelius Pass Portland OR 97231 FAX 629-0665

 

first off use exposure lock when taking the photos

secondly when blending photo edges use a layer mask with the gradient
tool and choose foreground to transparent

 

If your camera doesn't have it, hold the shutter down halfway at the
'main' frame and rotate out from there to snap down.

 

Looking at your photo's the biggest problem that I can see is that the
center of the panorama is shooting directly into the sun. A bad idea.
You should try to shoot your photo's with the sun behind you. Pictures
taken directly into the sun present numerous exposure difficulties,
optical lense ghost's (glare spots) etc. The only thing you could have
done would be to set your shutter speed and or f/stop to the highest
setting for the central shots and tried to tweak your shots to the sides
of the center to adjust for the exposure differnce.

Richard

 

It is very hard to take panos of any width without getting the sun in
the picture or at least in that direction. That's why averaging out your
exposure before you set your manual setting on the camera is important.

You need to find the brightest and darkest places in your pano and get
the average. Of course, you need to know if your capture device will
handle such a wide dynamic range. Even with the nice dynamic range of
digital cameras, they won't usually cover enough to include bright sun
and dark shadows.

The trick then is to shoot two or three panos and blend the highlights
and shadows from the different exposures in Photoshop. That will give
you full dynamic range. However, you can't have moving objects in the pano.

BTW, setting your camera at the highest speed or F/stop will do nothing
for pano exposure control. Setting for manual control is what you need
to do.

Do you mean to tell us that you never shoot into the sun? You are
missing a huge chunk of photographic possibilities by keeping the sun at
your back. Learn to work with it.

Clyde

 

: BTW, setting your camera at the highest speed or F/stop will do nothing
: for pano exposure control. Setting for manual control is what you need
: to do.

: Do you mean to tell us that you never shoot into the sun? You are
: missing a huge chunk of photographic possibilities by keeping the sun at
: your back. Learn to work with it.

... and stop down as much as possible to minimize vignetting. I got screwed
on that on some panos I recently put together.

-Cory

--

*************************************************************************
* Cory Papenfuss *
* Electrical Engineering candidate Ph.D. graduate student *
* Virginia Polytechnic Institute and State University *
*************************************************************************

 

Time of day. Greater detail. A pano doesn't need to cover half the
horizon to be eye popping. Most of mine cover < 90Ëš, and when done
right, are fine.

I'd suggest also setting WB before setting a series for a pano, either
manually or at least in one of the presets. Sun behind makes a big diff.

That is not to say shooting into the sun doesn't have all kinds of uses
for other shots.

 

For moving objects in stitched panos, there are only two things you can
really do.

One is to cut out objects before you stitch, or at least before you
blend. If you have half an object on a frame, delete it before you
stitch. This works well for cars, people, etc. It doesn't work too well
for waves.

For waves and other less predicable objects, I find a variety of tools
to help. If it's small, the Healing Brush or Patch Tool can make it less
noticeable. If it's a more noticeable part of the picture, I will often
use a soft edge selection and copy key parts to another layer. Then move
the layer around to match as best I can. After merging the layers, the
Healing Brush and/or Rubberstamp is needed to touch up.

This method also works pretty well for horizons that didn't quite line
up. Sometimes I have Hugin line up the key horizontal lines in the
picture. This will put horizontal lines in the background or foreground
a tad out of whack. This happens mostly when I have shot handheld
because I wasn't lugging around my tripod and pano head. I select part
of the line area on either side, copy to a layer, move, rotate so the
ends line up on each side, merge, and then touch up. This can make a
line slightly slant a bit, but it's way less noticeable than a step.
This doesn't always work if the line in question is a large or key part
of the picture.

One tool that will sometimes come in very handy with objects like waves
is Liquefy. You can push parts of waves around to line up with other
waves. It works much better than you think it would many times.

Clyde

 

You might want to have a look at the following tools:

1. autopano-sift (Takes a selection of files and works out their
intersect points)
2. hugin (Calculates how to stitch these files together, and what sort
of perspective distorts to apply to each image.)
3. enblend (Takes the hugin output and removes the colour difference. I
think this is what you want, wasn't it?)

I'm not so sure I can help you with the moving parts, other than one
suggestion. When I played around with vertical panoramas (before I found
hugin), I noticed that the sky was severely distorted.

1. So I started taking pictures of the sky without the foreground in the
picture, at largest widescreen setting
2. Drop this behind my panorama-d images of the setting, scaling up if
need be.
3. Make sure each panorama image has an alpha channel and remove the sky
from them.
4. Apply a Gaussian blur or unsharp mask across the background sky to
remove any scaling up artefacts.

Maybe if you took a wide-angle picture of your moving elements, you
could do something similar, but with the moving elements at the front?

Joal