Android camera calibration without chessboard

1
votes

I know there is some post talking about this topic but I could not find my answer.

I want to calibrate my android camera without chessboard for 3d reconstruction, so I need my intrinsic and extrinsic parameters.

My first goal is to extract the 3D real system to be able to put some 3d Model on screen.

My step :

  • From a picture of a building I extract 4 points that represent the real 3D system

  • /!\ this step require camera calibration /!\

    Convert them to 3d Point (solvePnP for exemple)

  • Then from my 3D Axis I create a OpenGL projection and modelview matrix

My main problem is that I want to avoid a calibration step, so how can calibrate without chessboard? I have some data from android such as focal length. I can guess that the projection center is the center of my camera picture.

Any idea or advice? or other way to do it ?

1
androidopencvcamera-calibration3d-reconstruction
You could improve your question by writing what have you tried, what have you read. – Rui Marques
I'm working on this but some difficulties to understand cs.unc.edu/~marc/pubs/PollefeysIJCV04.pdf – kakou
Yes it is a hard topic but the article you have pointed is the right direction. Look for more resources about Structure from motion. – Rui Marques

1 Answers

3
votes

here is nochess calibation of qtcalib.

This scheme is recomended when you need obtain a camera calibration from a image that don't have calibration chessboard. In this case, you can approximate the camera calibration if you know 4 points in the image forming a flat rectangle in real world. Is important to remark that the aproximated calibration depends on the 4 selected points and the values that you will set for the dimensions of the rectangle