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androidopencvimage-processingjavacv

Image Calibration vs Camera Calibration

I am new to image processing. I have a data set of images and I want to perform calibration on those images based on a target image. I have surfed a lot on image calibration but the majority of the results yield camera calibration. I am confused as to whether these are same or different things. Can anybody explain to me the difference between these two terms?

On reading through one of the results on image calibration, I got to know that there are three steps that I need to perform:

  1. Bias Frame Calibration
  2. Dark Frame Calibration
  3. Flat Field Frame Calibration

Also, I need to perform this in Android. For that, I have figured out that I will need to use OpenCV or JavaCV.

So, I want to know if these 3 steps will be possible using OpenCV/JavaCV or not?

Solution

  • Calibration is process that is exploiting some knowledge about the data to reconstruct measurements to be more accurate or suite a specific need. As we have no idea what is the desired result of your calibration then it is hard to say.

    In general the difference is as follows:

    1. Camera calibration

      you got camera and want to achieve that captured images will suffice some condition. This process usually mean taking image of some predefined objects like color markers, geometry checker board, LASER sweeps, etc. This way you can obtain camera parameters needed to reconstruct some specific feature of image for any other image taken (assuming important parameters not change with time like camera position or exposure time ...)

    2. Image calibration

      Is similar but the input image can be obtained from different sources (different cameras, render, simulation, etc. ) or under different circumstances (exposure, lighting, etc.). In this case we have not the luxury of calibration process so instead we need to find some kind of know feature in the images and correct the rest of image (for example object of known size, color, temperature, etc.)

    So the difference is The Camera calibration is when you got single imaging device as a source of image and Image calibration is when you got multiple image sources (often unknown).

    I am not using OpenCV but as people using this lib for such tasks then it should have support for operations like this.

    Here small example of such operation: