Flat Stitching Workflow


(Robert Bieber) #1

I’ve done some big panoramas with hugin before, and it’s been great so far for correcting distortion. I just got my hands on a view camera though, and now I’m looking to do some stitching by physically shifting a digital back around on the film plane, which should mean that the images will stitch together perfectly without any correction needed.

So with that in mind, is there any simpler (and faster) software I can use to do this kind of less complicated stitching? Bonus points if it can somehow combine multiple RAW files into a single, stitched DNG, although I know that’s probably not super feasible.


(Mica) #2

The stitched dng isn’t feasable because to stitch the image, you have to at least demoasic the data, then it isn’t really raw anymore.

Hugin will stitch your files as well, similar to the way uoud use hugin to stack images.


#3

Have you seen this tutorial: http://hugin.sourceforge.net/tutorials/scans/en.shtml?
Is it a linear panorama?
Can you show some pictures to try stiching?


(Robert Bieber) #4

Interesting, I’ll have to give it a try. I haven’t actually gotten anything together to test with yet, I just got the whole thing finally up and running today. Hopefully I’ll have some examples soon, but what I’m going to be doing is literally shifting the sensor up and down, left and right along the plane of the image. It should be effectively flat (at least to the extent that the lens’ projection is flat), because the lens is staying put and I’m just sampling different sections of the image circle


(Robert Bieber) #5

Alright, so here’s an example: https://drive.google.com/open?id=1lbAk4-LqpSyd0fqUxvnCjGBKcKkqdbn4

That’s a Google drive folder that should have both a final stitched file and a ZIP file with all the constituent JPEGs in it soon (I’m leaving it uploading while I go to sleep). I cheated a little on this one with a diagonal object across a white background, so I didn’t have to shoot the entire rectangular area. Don’t mind my questionable use of camera movements, I’m still trying to get the hang of this whole view camera thing :stuck_out_tongue:

As far as stitching goes, though, hugin seemed like huge overkill, to the point that I had to correct the things it was trying to “correct” in Gimp after the fact (and it turns out a 120MP stitched image It introduced a noticeable color cast towards the bottom right of the image, and the process took forever. Is there any way I can tell it to just not even try to correct exposure and simply align and overlay the images? It seems like I have to select exposure either fused from stacks or fused from all images, right? Maybe fusing just from stacks would be less destructive, I’ll try running a version like that overnight.


#6

What Hugin version you are using?
Can you post corresponding pto-file ?

Discuss seem to block .pto-files, so rename it .txt


#7

first, run Hugin’s cpfind with --ransacmode hom -o %o %s, then optimize for R (roll), X (horizontal translation) and Y (vertical translation). adjust the preview to your liking and stitch with exposure corrected, low dynamic range ticked. to hasten the stitch, untick superfluous images from the preview. your example file set can be stitched with 4 images.


(Mica) #8

The settings in our hugin tutorial should work: https://pixls.us/articles/aligning-images-with-hugin/


#9

I did following:

  1. I chose pictures 2, 5, 9, 12

  2. In Camera and Lens data, write to HFOV (v) number 10
    kuva

  3. Controlpoints: Hugins CPFind
    Options: Postions (incremental …)
    kuva

  4. Click Fast Preview panorama
    kuva

  5. Select Projection, click Fit, change to Rectilinear
    kuva

  6. Crop
    kuva

  7. Go to Sticher:
    Click Calculate Optimal Size
    Choos Exposure correkted low dynamic range
    Change blender to buil-in
    kuva

8 . Stitch!
9. Picture img_002-img_0012.tif is over 200 MB. Here is smaller .jpg


(Robert Bieber) #10

Y’all are great, thanks for all the advice. I don’t know why it never occurred to me to look for a minimal set of images, but that should help a lot


(srowed) #11

I use Hugin for flat (mosaic) stitching to increase resolution on large-format film negatives using a digital camera. I made a video tutorial for this using a recent version of Hugin, as some of the tutorials on the web are for out-of-date versions and no longer work well.

This type of stitching is for stitching photos where the camera position shifts laterally, keeping the sensor in the same plane as the subject, or in my case shifting the film laterally while the camera is stationary. This differs from the more normal panorama where the camera (or rather the nodal point of the lens) rotates.

My tutorial is a screen capture video that’s about 15 mb. Can I upload it here?


(Mica) #12

I think you can drag and drop it in the editor window here.

If not, I’d recommend a PeerTube instance such as https://peertube.xyz/videos/trending or you can embed a YouTube link in the post.


(srowed) #13

Drag and drop didn’t work as it won’t accept .mp4 files. I’ll try some your other suggestions.


(srowed) #14

I’ve put it on peertube but it’s not loading well, at least on my computer. Maybe try it? https://peertube.xyz/videos/watch/fa20dd76-da08-4b02-92a4-a87e7f7174b7


(Mica) #15

Loads well for me!


(Robert Bieber) #16

That was perfect, thanks!


#17

@troodon I tried your guide to @Bieber’s pictures, but I did not get a good result. Can the problem be missing exifdata of @bieber’s pictures?


(Morgan Hardwood) #18

@patdavid could we commit @yteaot’s guide to the Pixls.us Hall of Guides?


#19

missing exif data shouldn’t matter, since hugin asks for the focal length when you load the images onto hugin. just set the field of view to something reasonable, i.e. less than 45 degrees or so - for flat stitching it’s not important.


(http://4232.cf) #20

This takes a lot or is my computer?