Go Back   Steve's Digicams Forums > Software > Panorama / Stitching

Reply
 
Thread Tools Search this Thread
Old Sep 14, 2003, 10:35 PM   #1
Senior Member
 
Alan T's Avatar
 
Join Date: Jun 2003
Location: Chester, UK
Posts: 2,980
Default Add blank canvas size space before stitching??

I have a Casio QV-5700 with an excellent panorama facility that shows the right-hand edge of the previous frame at the left-hand viewfinder edge of the next shot. In good lighting conditions and with an LCD monitor viewing aid, this makes it easy to produce a series of horizontal panorama shots that align quite well. I've experimented with a spirit level on a tripod, but I'm beginning to realise that I do just as well with a high shutter speed and alignment by eye using this panorama-shooting facility.

I've done a few well-received panoramas in the past from filmscanned 35mm negs, but they took me about a week each to produce using a straightforward image editor (PSP7).

When I come to stitching my recent digicam results together, I've used Casio's 'Panorama Editor' and 'Pixmaker Lite' from http://www.pixaround.com/. Panorama Editor is basic and primitive; Pixmaker Lite is slow & painful & fairly sophisticated on my 400MHz PII machine with 320MB RAM, but produces excellent automated results in the end.

HOWEVER, I find with both programs that it's a serious annoyance to lose bits of the image at the top and the bottom. I've therefore developed the technique of doubling the height of each frame with blank space (of a suitably tasteful background colour) at top & bottom before any attempts at stitching, using 'increase canvas size' in my image editor (PSP7.04 in my case). Sometimes, I've been able to fill in the blank space later with cloned image bits from nearby, after getting the main detail in the middle well matched & overlapped.

Is this an acknowledged and well-known technique, or have I made an invention? If the file sizes weren't so huge, even when compressed for the web, I could post results.

What are the pros & cons of padding one's images at top & bottom before stitching? Bill, I'm sure you'll have something to say, please?
Alan T is offline   Reply With Quote
Sponsored Links
Old Oct 21, 2003, 9:24 AM   #2
Senior Member
 
Join Date: Oct 2003
Location: Indian Rocks Beach, FL
Posts: 4,036
Default

Different stitching software requires more or less overlap. The Camedia software that comes with Oly cameras will stitch with just the overlap resulting from exactly lining up the edges of the shots in an optical finder and counting on the 85% coverage of the optical finders to provide the overlap. Panorama Factory wants more overlap so I donít use it. If you just line the shots up in the optical finder you will find you can take accurate panos without having to fill in much. Using the LCD requires a higher shutter speed and it is much harder to keep everything level IMO.

If you have some gaps to fill the clone tool would do a fine job as long as the missing parts were grass, sky etc that is easy to clone. I would do it after the raw stitch so the cloned areas donít confuse the stitching software. If you set linear for the output you will find there isnít that much to fill in if you learn to take your panos with the optical finder.

If you are holding the camera horizontally try taking the shots holding the camera vertically. You get a lot more image in the pano and donít have to nit-pick a few lost pixels. Iíve even done Pixaround 360s with the camera held vertically Ė it would take a while to stitch that on a 400Mnz computer.
slipe is offline   Reply With Quote
Old Oct 21, 2003, 5:10 PM   #3
Senior Member
 
BillDrew's Avatar
 
Join Date: Jun 2002
Location: Hay River Township, WI
Posts: 2,512
Default

Slipe is right - from the comments I've seen, every stitching program has its own quirks, foibles, ...

I haven't seen any comments about folks using the technique Alan T mentioned to deal with the auto cropping some programs do. Sounds like it would work so long as the stitching program doesn't demand that it have some contrasty points near the edges. I have found that I also like the looks of uncropped panos. Though it really has to be done after stitching, using a drop shadow to emphasize the edges, like this:


Though I often shoot panos hand held, the results are better with a tripod - of course using a tripod always improves a shot that isn't time critical, pano or not.
BillDrew is offline   Reply With Quote
Old Oct 22, 2003, 2:03 AM   #4
Senior Member
 
Alan T's Avatar
 
Join Date: Jun 2003
Location: Chester, UK
Posts: 2,980
Default

Quote:
Originally Posted by BillDrew
using a drop shadow to emphasize the edges
That's a nice effect - thanks for the tip - and most useful when artistic cloning to fill in the white space proves too difficult or tedious.
Alan T is offline   Reply With Quote
Old Oct 24, 2003, 12:43 PM   #5
Senior Member
 
Join Date: Oct 2003
Location: Indian Rocks Beach, FL
Posts: 4,036
Default

Quote:
Originally Posted by BillDrew
I have found that I also like the looks of uncropped panos. Though it really has to be done after stitching, using a drop shadow to emphasize the edges
I really like that shot. Rather than eliminate a problem just emphasize it and use it as an enhancement Ė neat!


Quote:
Though I often shoot panos hand held, the results are better with a tripod - of course using a tripod always improves a shot that isn't time critical, pano or not.
A tripod will give a sharper image and perhaps a better thought out one. But it has been my experience that you can do better panos if you just practice hand holding them. A tripod increases rather than decreases the difficulty IMO. Maybe when you start stacking both horizontally and vertically a tripod would improve the accuracy. But I do better hand holding in a single plane.
slipe is offline   Reply With Quote
Old Oct 24, 2003, 7:23 PM   #6
Senior Member
 
BillDrew's Avatar
 
Join Date: Jun 2002
Location: Hay River Township, WI
Posts: 2,512
Default

Thanks for the kind words about the bailing pano. Just about any photo can be improved by using a tripod, unless
there isn't time to use one. That pano was hand-held (pretty obvious when it isn't cropped) because I didn't
happen to have my tripod with me. I would have had a much harder time shooting this one without a tripod:

Since it was shoot with each frame a few minutes apart - the time it took for the tractor to get arround the field -
it would have been difficult to hold the possition and horizontal from shot-to-shot.

It is also an example of an image any of the automagical stiitching programs would have a hard time
with because there is a critical path the stitching line has to take to avoid cutting the tractor.
BillDrew is offline   Reply With Quote
 
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -5. The time now is 2:30 AM.