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Old Oct 6, 2005, 8:20 AM   #1
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I don't have a pic at this time and nor would it be of use due to the large size. I may later display a few crops of the problem areas when I get home since I am at work right now.

Here is the thing. I have 45 4mp pictures that I shoot in two rows with about 66% overlap. I thought overlaping this much would reduce the chances of problems occuring.

The subject is the view of Cincinnati on top of it's highest building 574 feet above ground (I have a small version of the current pano in the critiques section. Link here: http://www.stevesforums.com/forums/v...mp;forum_id=90). This view contains hundreds of small houses, churches, buildings, as well as larger music halls, corporate building, and the like.

The probelms I am having is throught the entire image there are areas were the stictch line is visible. It may go right through a building or street block being misaligned just slightly. Other problems is that a church steple is detatched from it's building or that a road shifts like there has been an earthquake.

I am using Autopano Sift to find control points at full resolution. I then use the Panotools front end called Hugin to line up the images and correct for things like position, view, distortion, etc and add horizontal and vertical guidelines. Lastly I use enblend to do the stiching.

When the above problems occured I went back to hugin and placed control points over every singe problem areas and re-optimized the picture to again make sure the position, view, and distortion have been corrected. I then reran enblend to see if this would solve the problem. Unfortunetly it only fixed a few of the stich areas, most remained, and now a few new ones were added. I had over 4200 control points for these 45 photos and the resulting image was about 40mp after cropping.

So this leads me to some questions:
  1. Does overlapping by 66% create problems compared to 33%-50% overlap? If so should i remove every other picture and try it with a 33% overlap? (this would save hours on processing too) [/*]
  2. I put horizontal guidlines on all images that had the horizon and not on ones that didn't. Would this create a problem? [/*]
  3. I put vertical guidlines only three times. One on the left side, middle, and right on the pano. Should I have put more? [/*]
  4. I tried to output as mulitlayer tiff to possible use it with the stiched image to try to "blend" the problem areas out. Why won't photoshop elements 1 open it? Gimp will, why not elements 1? [/*]
  5. I converted the mulitlayer tiff in gimp to a photoshop file. I haven't tired to see if it is okay but the psd file is now 524mb, the stiched image is 279mb. I only have 640mb of ram. Will this be a problem in elements 1? [/*]
  6. Any thing you can tell me that may help please do. I am getting frustrated as each time I rerun enblend it is a 7 hour wait (mylaptop is a 1.7ghz p4m, 640ram, 30gb harddrive [with 4gb free space]).[/*]
By the way the pano was shot on a tripod with a 3 axis bogen head.

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Old Oct 6, 2005, 8:58 PM   #2
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An impressive amount of work and a good result as well.

I would cut down the number of "frames" by reducing the overlap. It isn't likely to reduce the problems by much if at all, but itmight reduce the size of the layered output to the point where you can work on it.

Whenlooked at in enough detail, pretty much every stitching job will show flaws. Many of those can be hidden byputting thestitch line where the flaw does not show, .e.g., down a tree trunk, a road, ... When that fails, the clone brush will most often do the trick.

A suggestion: try some simpler stitching jobs. If your aim is multirow panos, do several hand-held 2x2 panos of subjects with strong horizontal and vertical freatures - buildings as an example. Thoseshould have enough flaws that you will learn how to deal with them before tackling the massive job you outlined.
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Old Oct 7, 2005, 8:01 AM   #3
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Thanks for the suggestions, especially the one about reducing the multilayer tiff size to a more workable solution. Putting together a quality highly detailed pano is harder than I thought!
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Old Oct 10, 2005, 7:58 AM   #4
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Well I redueced the number of pics from 45 to 25 and it did help reduce the noticability of the errors by probably about 50% but they still remained. So at least in my case, overlaping 66% caused more problems then it help. Overlap at 33% seemed to work much better.

Well, I tried the multilayer tiff and the stiched image both loaded into elements version 1. Looking at the task manager I noticed that about 500mb ram was used and about 500 mb of virtual ram (hdd space) was used as well. I am assuming this is in addition to the scratch space that PSE uses once the memory size was beyond the limit I set (500mb since my lapto is 640mb).

I started to work on the file by deleting portions of the stiched image to allow the underlaying layers to show thru. This worked in some places but not in all. I had to use the clone brush to solve many errors. Some impossible errors I needed to use artistic license to add trees or the like to cover over problems. Well after about 2 hours I was about 20% done with the file and PSE locks up. It takes about 20 minutes to save the file so I hadn't done it in about 1.5 hours.

Needless to say there has too be an easier way. When looking at the image I would estimate that abuot 30% of the entire stitch has areas that need extensive toughing up (i.e. a diaganol sticth that runs thru sever city blocks that makes all the affected building's roofs not line up, as well as streets, stadiums, fields, and polls. Simply using the layers doesn't work as it just shifts the problem done further in the image. It is very time consuming to fix this problem.

Unfortunely, It also appears that my PS program is messed up now. Every time I load an image, even normal sized ones, When I click on "view histogram" or "unsharp mask" I either get the eye dropper icon or the square seletor that is used for the preview of the unsharp mask but no form pops up displaying the historgram or unsharp mask parameters. It then locks up. I am guessing some files have been corrupted when I had to kill the process when it locked up with the large file mentioned above.

I tried to install PS elements over the existing installation without uninstalling first because I have alot of plugins I don't want to reload if possible. This didn't fix the program. Has this happended to anyone before? Could it be that I need to delete the PS cache? IF so were is this located? I will post this part (about the ps problems) in a more applicable section of this forum too.

Thanks for you help.
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Old Oct 10, 2005, 8:40 AM   #5
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nelmr wrote:

Quote:
...
I started to work on the file by deleting portions of the stiched image to allow the underlaying layers to show thru. This worked in some places but not in all. I had to use the clone brush to solve many errors. Some impossible errors I needed to use artistic license to add trees or the like to cover over problems. Well after about 2 hours I was about 20% done with the file and PSE locks up. It takes about 20 minutes to save the file so I hadn't done it in about 1.5 hours.
...
If your software has it, usingmasked layers (reversible) instead of deleting (irreversible)is worth figuring out.

No one ever does back-up often enough, and everyone regrets that at some time.

nelmr wrote:

Quote:
...
Needless to say there has too be an easier way. When looking at the image I would estimate that abuot 30% of the entire stitch has areas that need extensive toughing up (i.e. a diaganol sticth that runs thru sever city blocks that makes all the affected building's roofs not line up, as well as streets, stadiums, fields, and polls. Simply using the layers doesn't work as it just shifts the problem done further in the image. It is very time consuming to fix this problem. ...
If you are really picky, I doubt there is an easier way. Itmight bepossible to improve your shooting to reduce the number of errors, but there will always be some.

I thinkpart of thesolution is to keep in mind what the final presentation will be. Do some test prints of thesome sections of your stitching with various degrees of problems. If you figure the largest you will print is 13 inches tall, crop an area 6/13ths talland the width to make a 4:6 aspect ratio, then get some cheap prints made. That will give you a good idea of where the corrections are Good Enough.

_________

edit: changed "adjustment layers" to "masked layers" - slip of the fingers.

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Old Oct 10, 2005, 8:46 AM   #6
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I cant say much as to the perfect way to edit panos as I only use autostitch for quick ones. maybe give autostitch a try and see what it can do. cant hurt. all you have to do is select the files and let it run. Perhaps it will turn out better.

On the other hand, I can speak to the computing power. Your laptop is not really the kind of machine to be doing extensive editing on. Especially on such large files. A 500 dollar investment here in an althon64, 1gig of ram and a 300 gb hard drive would save many hours of your life.

Another suggestion, work on the pano in peices. for example if you have 21 photos total, pano the first 7, 2nd 7, and third 7 in seperate sessions. Then in another session, stitch together the 3 panos into the final piece. Good luck.
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Old Oct 10, 2005, 8:46 PM   #7
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VAtechtigger: Hey isn't VA Tech the home of the Mac supercomputers?

Anyway, ths only problem I see with working in pieces would be the perspective problems with merging panoramas. I've never tried it, but would imagine it would be more difficult to deal with in steps rather than all at once.

There was a post once about the world's largest panorama around here I think. I don't know what software he used but it could handle your panorama if it is available.
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Old Oct 11, 2005, 7:48 AM   #8
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I've heard of a couple of 1GP+ panos or stitch jobs that used these three following programs: Autopano sift, PTA, and enblend. The only difference is that I am using Hugin (freeware) as my panotools front end instead of PTA (not freeware). No doubt PTA must be the better program.
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Old Oct 11, 2005, 8:29 AM   #9
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srvsd wrote:
Quote:
VAtechtigger: Hey isn't VA Tech the home of the Mac supercomputers?
Yep, its a pretty wired town. They also have/had the first active smartroad with all kinds of traffic sensors and computer controlled lights and signs.

I dont think the problem is with his software being able to handle his pano, its his computer being able to handle his pano. Its a little light on spec for the size files he is running.
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