Developing a batch file for mosaic stitching with the highest possible quality

[Bernd D]

Hello,

I would like to use panotools to stitch a photo-mosaic in batch mode. The information that I use is from here:

http://wiki.panotools.org/Stitching_a_photo-mosaic

http://hugin.sourceforge.net/tutorials/scans/en.shtml

http://hugin.sourceforge.net/tutorials/Mosaic-mode/en.shtml

(and so on)

First I create a batch file that automated the process for a 5x5 mosaic:

@ECHO OFF

@SET IMAGES=T??.tif

@SET PREFIX=Test

@SET HUGIN=c:\Program Files (x86)\Hugin\bin

@"%HUGIN%\pto_gen.exe" --projection=0 --fov=5 -o project.pto %IMAGES%

@"%HUGIN%\pto_lensstack.exe" -o project1.pto --new-lens i1,i2,i3,i4,i5,i6,i7,i8,i9,i10,i11,i12,i13,i14,i15,i16,i17,i18,i19,i20,i21,i22,i23,i24 project.pto

@"%HUGIN%\cpfind.exe" --multirow --fullscale -o project2.pto project1.pto

@"%HUGIN%\cpclean.exe" -o project3.pto project2.pto

@"%HUGIN%\pto_var.exe" -o setoptim.pto --opt TrX,TrY project3.pto

@"%HUGIN%\autooptimiser.exe" -n -o autoptim.pto setoptim.pto

@"%HUGIN%\pano_modify.exe" --projection=0 --fov=AUTO --canvas=AUTO --crop=AUTO -o autoptim2.pto autoptim.pto

@"%HUGIN%\hugin_executor.exe" --stitching --prefix=%Prefix% autoptim2.pto

 

Then I have written a simple tool that makes test images:

• generates a 4000x4000 image with random pixels
• draw cross marker every 20 pixel
• draw  a one pixel wide frame
• Save the resulting image
• Cut 5x5 tiles, with 1000x1000 Pixel (250 pixel overlapped) and save this to image T00.tif..T24.tif.

The random pixels cause that each pixel is a very good comparison candidate for finding Control Points. The marker and the frame facilitate the interpretation of the stitching result.

I expected that panotools can stitch these tiles together only with errors in sub pixel dimension. But the error is significantly larger. After much trial and error I found a solution for this particular case. Based on the test images, I found out that pano_modify.exe caused the error. This program calculates the p line in autoptim2.pto:

p f0 w6857 h6857 v129  E0 R0 S2928,6857,2928,6857 n"TIFF_m c:LZW r:CROP"

I can correct this manually:

• Open autoptim2.pto in hugin

• On Sticher Tab, Change Field of View, Horizontal and Vertical  from 129 to 130.

• Press the “Calculate optimal size” Button.

• Press the “Fit crop to images” Button

The result is:

p f0 w7014 h7014 v130  E0 R0 S3007,7007,3007,7007 n"TIFF_m c:LZW r:CROP"

 With these settings, hugin produces a sub pixel accurate image. Of course, that is not really a useful solution for me, because my batch file must provide a correct output image for any set of input images.

Now my questions:

1. How can I automatically calculate the correct Field of View? Or even better: Is there a way, to bypass the unnecessary Field of View parameter, so that the intermediate images are not scaled.?

2. How can I avoid that w and h are unnecessarily large? Better as

    p f0 w7014 h7014 v130  E0 R0 S3007,7007,3007,7007 n"TIFF_m c:LZW r:CROP"
   would be
   p f0 w4000 h4000 v130  E0 R0 S0,0,3999,3999 n"TIFF_m c:LZW r:CROP"
   Expressed differently: How can I shift the projection to a minimum canvas? Or is the canvas size only a virtual size which is not physically created?

3. Why does the command line parameter " --dry-run "for hugin_executor not work? See  http://wiki.panotools.org/Hugin_executor. Are the individual commands documented somewhere else?

If someone wants to try the test, here is my test image generator tool:

http://www.file-upload.net/download-11778244/I2T.zip.html

Viruscheck: https://www.virustotal.com/

SHA256: ca729b9ba382d63a831a416fed2389647433476f1424b7616591a8abc2297e1d

File name: I2T.exe

  

To create the test images: Press „Random“ Button, Press „Draw Marker“ Button, Enter the target directory in the box to the left of the "Save" button. Press the „Save“ Button.

Thanks in advance

Bernd Derer

[Abrimaal]

On Wednesday, July 20, 2016 at 10:54:22 AM UTC+2, Bernd D wrote:

Hello,

I would like to use panotools to stitch a photo-mosaic in batch mode. The information that I use is from here:

http://wiki.panotools.org/Stitching_a_photo-mosaic

(...)

 Hugin is generally for photos taken with various lenses. I was trying to stitch a map according to the tutorial above, but the image was always distorted, there are too many parameters to input.
My suggestion to the developers is: Flat document stitching in the rectilinear projection with only these checkboxes at start
[  ] exposure correction
[  ] horizontal / vertical line detection
[  ] high contrast priority (for such documents as maps, technical drawings, scanned text) to restrict searching for control points

All the other steps are skipped. Optionally to allow enblend / enfuse when the images do not match exactly.