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[Paul <939370@xxxxxxxxxxxxxxxxxx>]

Control points in PTGuiPro where automatically detected, and led to no
stitching errors. Hence, the images are "good enough" for automatic
control point detection and automatic stitching.

Hugin failed to replicate this behaviour. Only *AFTER* I *manually*
placed control points AND *manually* directed the optimization by
selectively optimising placement photo by photo, I was able to arrive at
an acceptable panorama.

Don't tell me to fix up the control points, because that is what I did
already to arrive at an acceptable result, AND it missed the point of
the bug report. The point I made, is that in Hugin's automatic
calculations, it will not converge to a good solution, while PTGUIPro
can do so for the same set of images.

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https://bugs.launchpad.net/bugs/939370

Title:
  Default Align cannot correctly align images, probably due to wrong
  calculated lens parameters

Status in Hugin - Panorama Tools GUI:
  Won't Fix

Bug description:
  Operating System: Windows XP (build 2600, Service Pack 3)
  Architecture: 32 bit
  Free memory: 1554316 kiB
  Active Codepage: 1252 (Western European Windows)

  Hugin
  Version: 2011.4.0.cf9be9344356 built by Matthew Petroff

  --

  When stitching a simple (partial) panorama, consisting of 7 handheld
  portrait shots, Hugin fails to automatically find a correct alignment
  when using the 'Align' button.

  Workflow:
  1. Load images
  2. Align

  The shown image in the preview has an S-shape (which can be somewhat
  corrected by using the 'straigthen' button), but more importantly, the
  3 images on the right are not correctly matched, giving a very large
  sharp 'bend' in the image.

  I loaded up the same images in a trial version of PTGUIPro to compare,
  using only 'Load images', and the 'Align images'. PTGUIPro showed a
  completely correct panorama.

  When comparing the two panoramas, I found that the calculated lens
  parameters were very different.

  Hugin has:
  Degrees of view : 69.38707
  Focal length: 4.1
  Crop factor: 6.09756

  Image center shift:
  hor (d) -8.42
  ver (e) -22.89

  Radial distortion:

  a: 0
  b: -0.01169
  c: 0

  Image shear (g) : 0 (t) : 0

  PTGUIPro has:
  Horizontal Field of View: 52.52 (actual) 54.88 (as found in EXIF)
  Focal length: 4.315
  Focal length multiplier: 6.098

  Image shift hor (d): 29.76
  Image shift ver (e): -0.08002

  Image shear (g) : 0 (t) : 0

  Lens correction:
  a: -0.0198
  b: 0.04955
  c: -0.05061

  
  Can it be that the difficulty Hugin has to create a correct panorama is due to these differences in calculated lens parameters?

  When I tried to apply the lens parameters from PTGUIPro directly into
  Hugin, the panorama was updated, but the individual images looked
  "shrunk" relative to each other, and did not fit well. So maybe, these
  lens parameters do not map 1-to-1 onto each other?

  Anyway the cause may be, Hugin is still not able to create a proper
  panorama.

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