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Hi,

I'm calibrating a GoPro Hero 4. I have calibrated using chessboard pattern. I would like to see if I can get a better calibration with the circles instead. However I'm having some problems determining the correct width/height.

Here is the pattern I'm using (generated with the included gen_pattern.py):

I'm using command: findCirclesGrid(img, (width, height), cv2.CALIB_CB_ASYMMETRIC_GRID).

I have tried all possible combinations of any way you could count the width (14 or 7) and height (5 or 10), and any combination of the two. I also tried rotating the image. It detected the pattern in the following settings:

Wide image, width=7, height=10:

Looks correct at first glance, but seeing how the dots connect, it's wrong.

Wide image, width=5, height=14:

Clearly wrong.

Tall image, width=7, height=10:

Same as [wide, width=7, height=10], the points aren't correctly connected so it's wrong.

Tall image, width=5, height=14:

Again, clearly wrong.

What am I doing wrong? Thanks in advance.

Hi,

I'm calibrating a GoPro Hero 4. I have calibrated using chessboard pattern. I would like to see if I can get a better calibration with the circles instead. However I'm having some problems determining the correct width/height.

Here is the pattern I'm using (generated with the included gen_pattern.py):

I'm using command: findCirclesGrid(img, (width, height), cv2.CALIB_CB_ASYMMETRIC_GRID).

I have tried all possible combinations of any way you could count the width (14 or 7) and height (5 or 10), and any combination of the two. I also tried rotating the image. It detected the pattern in the following settings:

Wide image, width=7, height=10:

Looks correct at first glance, but seeing how the dots connect, it's wrong.

Wide image, width=5, height=14:

Clearly wrong.

Tall image, width=7, height=10:

Same as [wide, width=7, height=10], the points aren't correctly connected so it's wrong. This is actually correct.

Tall image, width=5, height=14:

Again, clearly wrong.

So my questions are: 1. Why is there no correct way to detection the image in the wide orientation? 2. If I then choose the tall orientation of the image, does it only work if I had the actual image printout in the tall orientation, when posing it in front of the camera?

It seems somewhat less table to me than the chessboard, but I could be wrong?

What am I doing wrong? Thanks in advance.

Hi,

I'm calibrating a GoPro Hero 4. I have calibrated using chessboard pattern. I would like to see if I can get a better calibration with the circles instead. However I'm having some problems determining the correct width/height.

Here is the pattern I'm using (generated with the included gen_pattern.py):

I'm using command: findCirclesGrid(img, (width, height), cv2.CALIB_CB_ASYMMETRIC_GRID).

I have tried all possible combinations of any way you could count the width (14 or 7) and height (5 or 10), and any combination of the two. I also tried rotating the image. It detected the pattern in the following settings:

Wide image, width=7, height=10:

Looks correct at first glance, but seeing how the dots connect, it's wrong.

Wide image, width=5, height=14:

Clearly wrong.

Tall image, width=7, height=10:

This is actually correct.

Tall image, width=5, height=14:

Again, clearly wrong.

So my questions are: 1. Why is there no correct way to detection the image in the wide orientation? 2. If I then choose the tall orientation of the image, does it only work if I had the actual image printout in the tall orientation, when posing it in front of the camera?

It seems somewhat less table to me than the chessboard, but I could be wrong?

What am I doing wrong? Thanks in advance.