Photo stitching has weird skew when doing planar panoramas with Copterus

[Weston Ney]

I'm new to mapping but not new to gigapixel photography. I am trying to create high resolution top down photography of cityscapes and have been doing testing in my neighborhood to try to get my settings and techniques figured out.

I took the attached photo using Copterus with my Air 2S. It took 200 photos from 200 feet up and 70% overlap. (The attached photo is low res for posting purposes, the original photo is 371 megapixels.)

I stitch the photos using Microsoft ICE, using the planar mode. It does a great job, except for the houses. The perspectives on the houses look strange. They look tilted and not top down, and some houses you can see walls from both the east and west side at the same time! Any tips on how to prevent this? I thought having so much overlap would help, but I guess not.

Thank you!
-Weston

 

[Meta4]

I'm new to mapping ....
I stitch the photos using Microsoft ICE, using the planar mode. It does a great job, except for the houses. The perspectives on the houses look strange. They look tilted and not top down, and some houses you can see walls from both the east and west side at the same time! Any tips on how to prevent this? I thought having so much overlap would help, but I guess not.

Microsoft ICE is a simple photo stitching program.
Creating orthophoto mosaics requires a much more complex program like Agisoft Metashape.

 

[RodPad]

@Weston Ney
Hey man!, Haven't seen anything from you for awhile
Remember you on the PP.

Rod ..
.

 

[doncooke]

If you take all the pictures from the same place, then the camera is going to see walls on houses that are off to the side. Perhaps you want an orthophoto, which is an artificially-generated image with everything displayed from above. I use Dronelink to plan a mapping mission and control the drone, then WEBODM to compute the orthoimage. This is Dronelink's flight path to make an ortho of my RV park: 400' elevation with 80% overlap. About 375 photos; I had to drive the drone (Mini-II) home to change batteries mid-mission.
The result is about 77 megs (thumbnail):
Click on the thumbnail of the attached image of one of the 283 RV Sites at full resolution.

 

[Nifty]

Microsoft ICE is a simple photo stitching program.
Creating orthophoto mosaics requires a much more complex program like Agisoft Metashape.

I agree. Used Agisoft Metashape to stitch thousands of UAV images of irrigation channels for a research project. No mis-shapen objects just clean sharp ortho-photo-mosaic images. Perfect for your task , if flown in a grid pattern as above.
Neville
Australia

 

[JeffreyS]

Weston, it doesn't look like you were shooting straight down, but I may be wrong. DonCooke has the right idea in that you need to look straight down and move the drone to numerous positions that overlap the view of each. I don't know why you need to make so many exposures and create such a big file. You can probably get the results you need with less.

 

[Meta4]

Weston, it doesn't look like you were shooting straight down, but I may be wrong. DonCooke has the right idea in that you need to look straight down and move the drone to numerous positions that overlap the view of each.

Looking straight down from several positions will show the walls of buildings that are located away from the centre of the images.
As the drone moves around the site, it will capture walls on two sides or more for many buildings.

I don't know why you need to make so many exposures and create such a big file. You can probably get the results you need with less.

Because photogrammetry isn't a simple photographic stitch.
It relies on having lots of images and large overlaps to make the corrections needed.
70% is a common default but this can be increased when the scene needs more.

 

[Kilrah]

Proper photogrammetry software will also use GPS coordinates of each photo to figure out which one is most relevant to use for a particular area,

 

[PanoVolo]

ICE assumes your photos are projected on a sphere, not on a plane. So the distortions will be more visible towards the edges of panorama.

You need mapping as was said above.

 

[brett8883]

I'm new to mapping but not new to gigapixel photography. I am trying to create high resolution top down photography of cityscapes and have been doing testing in my neighborhood to try to get my settings and techniques figured out.

I took the attached photo using Copterus with my Air 2S. It took 200 photos from 200 feet up and 70% overlap. (The attached photo is low res for posting purposes, the original photo is 371 megapixels.)

I stitch the photos using Microsoft ICE, using the planar mode. It does a great job, except for the houses. The perspectives on the houses look strange. They look tilted and not top down, and some houses you can see walls from both the east and west side at the same time! Any tips on how to prevent this? I thought having so much overlap would help, but I guess not.

Thank you!
-WestonView attachment 172017

It looks better like that in all honesty though. If it’s straight down it just looks like a satellite image

 

[Weston Ney]

If you take all the pictures from the same place, then the camera is going to see walls on houses that are off to the side. Perhaps you want an orthophoto, which is an artificially-generated image with everything displayed from above. I use Dronelink to plan a mapping mission and control the drone, then WEBODM to compute the orthoimage. This is Dronelink's flight path to make an ortho of my RV park: 400' elevation with 80% overlap. About 375 photos; I had to drive the drone (Mini-II) home to change batteries mid-mission.View attachment 172035
The result is about 77 megs (thumbnail): View attachment 172037
Click on the thumbnail of the attached image of one of the 283 RV Sites at full resolution.

I tried WebODM on both my Mac and PC, on Mac it doesn’t launch, not even on my M1 Mac. On my high end PC it crashes and goes black screen and I have to power cycle my pc. I’ve only gotten it to work using their lightning service which is annoying.

 

[Weston Ney]

Weston, it doesn't look like you were shooting straight down, but I may be wrong. DonCooke has the right idea in that you need to look straight down and move the drone to numerous positions that overlap the view of each. I don't know why you need to make so many exposures and create such a big file. You can probably get the results you need with less.

I was shooting straight down using Copterus to get consistent overlap. I’m still getting the hang of this but my capture method was sufficient, my problem is the post processing. I also took a lot of photos for fun because it’s cool to make gigapixel images.

 

[Kilrah]

ICE assumes your photos are projected on a sphere, not on a plane.

You can tell it it was a plane, even tell it the grid layout you used. E.g. this does not work with auto settings because it assumes the 2 identical rows on the chip are a duplicate, but when you tell it it does it right.

Might need to align the rotations first though, haven't tried with varying ones in a while.

 

[brett8883]

You can tell it it was a plane, even tell it the grid layout you used. E.g. this does not work with auto settings because it assumes the 2 identical rows on the chip are a duplicate, but when you tell it it does it right.

Might need to align the rotations first though, haven't tried with varying ones in a while.

View attachment 172137

View attachment 172139

View attachment 172140
View attachment 172141

That’s a dope way to photograph a chip. I bet it takes a super cool rig to take those

 

[Kilrah]

I just tried to see if I could repurpose my desktop CNC and 3D print some mounts and it worked

 

[brett8883]

I just tried to see if I could repurpose my desktop CNC and 3D print some mounts and it worked

View attachment 172163

View attachment 172164

That’s awesome. I would have never that!