Focal length in pixel calculation.

[kundu03]

Good Morning @pmoulon, currently i am studying OPenMVG library and i came across a problem like what if my drone is not there in the database. Then, I came across your formula for focal_pixel = 1.2 * max(width,height). When i am testing the data for GoPro 10, focal_pixel by this formula is 4800 and the value calculated from the sensor_width given in database is 1153.9708080322662. So, I want to know does it make some problems in future or not.

[pmoulon]

Hi.
Do note that the formula is an approximation for an opening of 90 degree. A GoPro is a fish eye lens and so that's why you note a difference. See here #669 (comment)

[kundu03]

Thank you @pmoulon

[kundu03]

Hi @pmoulon , i have one more doubt. Can you please tell how we can give custom keypoints so that we can have our required number of features.

[pmoulon]

Custom key point can be provided by filling .feat and match files