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Author Topic: Fisheye support OMG!!!  (Read 58903 times)

bigben

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Fisheye support OMG!!!
« on: September 25, 2014, 02:03:37 AM »
Late last week I started work on developing a strategy for shooting buildings and environments from ground level based on what I've learnt so far. The first test run (https://sketchfab.com/models/736c32f7ca1a47aaa00f3ece03d6e8b6 was quite fruitful, as I managed to anticipate most of the problems I'd have and most of my strategies worked. There were however a number difficult challenges for which there didn't seem to be many easy answers except for take a whole lot images that weren't necessarily going to contribute to the model.

And along came the pre release and fisheye support. Nearly all of the difficulties I'd had related to space restrictions making it difficult to create tie points around corners. A fisheye lens is going to be useful for this because I can get both the building and the ground in the frame at close range, with the ground providing tie points around the corner.  Ran a quick test on the corner of a building at work and it was very promising. (Canon 1Ds III, 15mm f2.8 ) 

Went back yesterday and shot the whole building, including one wall where there was only 2m of space. As I was shooting it though, I kept thinking of  what I'd seen in the previous test and what else might work. I went a little overboard and 500 photos later I'd captured the building, surrounding gardens and a table setting. Did a quick alignment of 20 images to see what it was going to look like and was excited to see peripheral areas that I wasn't even thinking of showing up. The main chunk of 300 photos is processing now, but my mind has been in overdrive thinking of the possibilities for the various researchers I work with.
I'm going to predict that fisheye support in PS is going to en up a whole new range of possibilities and applications.

Bring on the revolution!  :D
« Last Edit: September 25, 2014, 07:50:14 AM by bigben »

igor73

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Re: Fisheye support OMG!!!
« Reply #1 on: September 25, 2014, 02:27:01 PM »
Also very interesting to me as i work underwater. Have used 16mm fisheye an tha past and it seemed to work quite well.  Now using 16mm rectilinear though. 
Is there a new pre realese that is supposed to work better with fisheye?  Where is the download link?

igor73

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Re: Fisheye support OMG!!!
« Reply #2 on: September 25, 2014, 02:28:52 PM »
Another question.  I see you use TIFF images.  Are you finding a great improvement over JPG? 

bigben

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Re: Fisheye support OMG!!!
« Reply #3 on: September 25, 2014, 03:09:55 PM »
See the sticky announcement http://www.agisoft.ru/forum/index.php?topic=2883.0

As for using TIFF, I shoot camera raw and then fine tune exposure and contrast. The resulting image is substantially different from the camera JPEG.  I also have a Photoshop action to create a quick mask of the sky and I find it easier to have this as an alpha channel in the image... and finally, there are no compression artefacts to add noise.

igor73

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Re: Fisheye support OMG!!!
« Reply #4 on: September 25, 2014, 05:36:06 PM »
Do you have to do a camera calibration when using the fisheye or is PS taking care of that automatically from exif data? 

bigben

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Re: Fisheye support OMG!!!
« Reply #5 on: September 25, 2014, 06:28:46 PM »
PS takes care of the calibration but you have to specify that it's a fisheye lens.

ThomasVD

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Re: Fisheye support OMG!!!
« Reply #6 on: September 25, 2014, 06:54:28 PM »
Nice results with the fisheye support, and thanks for the tip on having to select "fisheye" under camera type in the camera calibration menu (I thought it was just going to be automatic)!

I'm using fisheye GoPro imagery to recreate several underwater archaeological sites in 3D and so far the results are pretty good :)

igor73

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Re: Fisheye support OMG!!!
« Reply #7 on: September 26, 2014, 12:17:30 AM »
Thomas,

Did you film with the Go Pro and used frame grabbs ?  Have been thinking of trying this with a 5k camera like the red epic.

 


bigben

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Re: Fisheye support OMG!!!
« Reply #8 on: September 26, 2014, 12:26:01 AM »
I'm using fisheye GoPro imagery to recreate several underwater archaeological sites in 3D and so far the results are pretty good :)

Can we see one? even a screenrgab?
[edit] NVM, checking your other threads ;)
« Last Edit: September 26, 2014, 12:28:15 AM by bigben »

mrb

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Re: Fisheye support OMG!!!
« Reply #9 on: September 30, 2014, 12:07:28 AM »
I've made numerous photoscan models using a gopro as well as a DSLR+10mm lens:

https://skfb.ly/AYpt

https://skfb.ly/ATY6


bcoyle

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Re: Fisheye support OMG!!!
« Reply #10 on: January 18, 2015, 01:55:11 AM »
This is sweet! Are they any specific steps that need to be taken to get a fish-eye lens to process correctly? My initial test with a few fish-eye pictures showed a facade with an overall bend to it...

bigben

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Re: Fisheye support OMG!!!
« Reply #11 on: January 18, 2015, 07:21:36 AM »
I'm back into a testing phase again, so I'll be loitering around for a while again ;)
This is sweet! Are they any specific steps that need to be taken to get a fish-eye lens to process correctly? My initial test with a few fish-eye pictures showed a facade with an overall bend to it...

Assuming you've set the lens to fisheye in the lens calibration options before processing, I'm going to guess that this is a relatively short, single row of images.  I'm processing some images for another team using a GoPro4 on a UAV and the first small test showed this problem.  The second test had 5 rows of images, 4 different heights and 2 from above (they were just after a single side of the building and the roof)  The result was very promising and the best result I've produced with GoPro images yet. (attached)

Over the next weeks I'll be looking at different camera orientations/configurations of multiple cameras on a pole with the aim of coming up with a setup to rapidly scan an environment.  After seeing this result I could accept the use of GoPros on the understanding that the end resolution will be limited, but if the concept is successful it will then be a case of exploring different resolution cameras.


bigben

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Re: Fisheye support OMG!!!
« Reply #12 on: January 18, 2015, 07:50:07 AM »
I've made numerous photoscan models using a gopro as well as a DSLR+10mm lens:

https://skfb.ly/AYpt

https://skfb.ly/ATY6

Do you mix in groud-based images with your UAV work?

ThomasVD

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Re: Fisheye support OMG!!!
« Reply #13 on: January 18, 2015, 06:56:41 PM »
Hey Igor,

Sorry for the late reply, clearly I don't check the forums frequently enough.

That is indeed what I did: video recording, then frame grab using "free video to JPG converter". Makes it a lot easier to provide sufficient overlap between images! The wide angle lens also allows for more data to be recorded in less images. It's also the same procedure other researchers recently used on the Gnalic archaeological site http://nauticalarch.org/blogs/gnalic-project/.

HOWEVER - I noticed that results with PhotoScan set to 'fisheye' actually aligned LESS well than aligning with normal settings. My guess is that this is because the fisheye camera actually compensates for some of the light refraction that normally causes perspective distortion underwater (this is why many traditional underwater camera housings have a 'dome' in front of the camera lens). As such pictures caught using a fisheye camera underwater are actually less distorted than pictures caught with a fisheye lens on land, and as such the 'fisheye' setting in PhotoScan appears to work less well on underwater images.

Tom

ThomasVD

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Re: Fisheye support OMG!!!
« Reply #14 on: January 18, 2015, 07:04:17 PM »
And demos (in case you still want them BigBen :)
Demo 2 is of a tile wreck with good visibility, so just 44 frames were needed.
Demo 1 is of a deeper wreck with bad visibility, and as such we had to get very close to the remains while recording. Consequently 7000+ video frames were aligned in 11 different chunks and then individual chunks aligned and merged using marker-based alignment.