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Author Topic: bad calibration of the lens.  (Read 5410 times)

kris3d

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bad calibration of the lens.
« on: September 15, 2012, 04:23:38 PM »
I have a continuous problem with the calibration of the lens.
The calibration parameters of the camera is bad. <cx> and <cy>, are reversed. Image rotation is 90 degrees.
How do I convert my calibration to the correct orientation.
I ask for help.
I think that my calibration is wrong .73 mm
Because as her turn, the program aligns properly.

Does it matter how taking pictures.
Whether they are vertical or horizontal


73mm

<?xml version="1.0" encoding="UTF-8"?>
<calibration>
  <fx>1.1895638799091885e+004</fx>
  <fy>1.1903541828061305e+004</fy>
  <cx>2.8639717769360595e+003</cx>
  <cy>1.9657232283640105e+003</cy>
  <skew>0.0000000000000000e+000</skew>
  <k1>2.4962622721719538e-001</k1>
  <k2>-1.6549059383569611e-002</k2>
  <k3>1.4308350414794238e+000</k3>
  <p1>5.3215485840205721e-003</p1>
  <p2>2.5880640359471274e-003</p2>
  <date>2012-09-13T16:25:42Z</date>
</calibration>


24mm


<?xml version="1.0" encoding="UTF-8"?>
<calibration>
  <fx>3.7221673101922102e+003</fx>
  <fy>3.7234713716135716e+003</fy>
  <cx>2.7909784559193295e+003</cx>
  <cy>1.8781332703852161e+003</cy>
  <skew>0.0000000000000000e+000</skew>
  <k1>-1.4015123127184947e-001</k1>
  <k2>7.7828931083552308e-002</k2>
  <k3>-2.3212033524347912e-002</k3>
  <p1>1.1152600142718013e-003</p1>
  <p2>-1.5600231530303525e-003</p2>
  <date>2012-09-14T16:05:03Z</date>
</calibration>

32mm

<?xml version="1.0" encoding="UTF-8"?>
<calibration>
  <fx>5.0255643137369843e+003</fx>
  <fy>5.0261392564557518e+003</fy>
  <cx>2.7911296449565157e+003</cx>
  <cy>1.8820381351645769e+003</cy>
  <skew>0.0000000000000000e+000</skew>
  <k1>-7.1226392049854453e-002</k1>
  <k2>1.2348182465707574e-001</k2>
  <k3>-1.1959963398987421e-001</k3>
  <p1>1.1400547687467650e-003</p1>
  <p2>-1.2010307621389299e-003</p2>
  <date>2012-08-25T11:07:27Z</date>
</calibration>

Alexey Pasumansky

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Re: bad calibration of the lens.
« Reply #1 on: September 15, 2012, 04:39:24 PM »
Hello kris3d,

Camera rotation doesn't matter on the processing result.

Even photos are taken in portrait orientation, they are still stored in horizontal orientation and are rotated only by visualization software (unless images are manually rotated in the editing applications, but transformed images are unrecommended to be used in PhotoScan).

In PhotoScan Workspace pane you can see image preview where width and height values don't depend on camera orientation. So in most cases cx should be greater than cy, even the image was taken in the portrait  camera orientation.

Do you experience any problems with aligning original (untransformed) images?
Best regards,
Alexey Pasumansky,
Agisoft LLC

kris3d

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Re: bad calibration of the lens.
« Reply #2 on: September 15, 2012, 04:45:42 PM »
I think that my calibration is wrong .73 mm
Because as her turn, the program can not properly align.
And cameras are placed randomly

These pictures are pictures cut by

Alexey Pasumansky

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Re: bad calibration of the lens.
« Reply #3 on: September 15, 2012, 05:15:55 PM »
Hello kris3d,

Have you tried to align photos without manual calibration input? Since usually EXIF data stored with the images is enough for initial parameters (as you are using good DSLR camera).

Quote
These pictures are pictures cut by
Please note that cropping, rotating and other transformations performed with original photos can affect the result.
Best regards,
Alexey Pasumansky,
Agisoft LLC

kris3d

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Re: bad calibration of the lens.
« Reply #4 on: September 15, 2012, 05:56:03 PM »
So I tried, and then it worked fine.
However, I wanted to get the best quality.
I used the calibration and alignment did not work.
I think it might be related with that situation.

There really helped Image rotation is 90 degrees.

http://www.agisoft.ru/forum/index.php?topic=574.45