# Understanding the Result of Camera Calibration and its Units

Hi,

I am quite new to camera calibration.

I have 35 images, based on the following functions :

findChessboardCorners() cornerSubPix() drawChessboardCorners() calibrateCamera()

I now have

- Camera Matrix - 3x3 dimension
- Distortion Coefficient - 1x5 dimension
- Rotation Vector - 35x3 dimension
- Translation Vector - 35x3 dimension

Questions :

**camera matrix**`[ 2421.70421334667, 0, 2138.107444179007; 0, 2429.244140012221, 1136.772764836856; 0, 0, 1]`

In the above , what are the units of fx, fy , Cx and Cy ?

**Distortion Coefficient**

`[-0.2877455633196141, 0.2968104208806526, -0.001127291269463514, -0.002010576239298727, -0.3457992571078199]`

Do we have any Units for K1, K2, P1, P2, K3 ?

**Rotation Vector**

`[-0.1019788539700399; 0.3918509002001774; 0.0734955967493143] [-0.1165422449849887; 0.5017699087572564; 0.4257284491781231] [-0.1233545118567792; 0.5922964766688477; 1.001270611741778] [-0.5253276710841507; -0.01653828323651414; -1.386034124708322] so on ... for all 35 images`

What about the unit of Rotation Matrix? How should I understand it? What does this values mean?

**Translation Vector**

`[152.8348988935562, -168.8318694822206; 951.100836109663] [191.0103136141713; -207.2053481732149; 963.7313891311128] [307.0885175766131; -212.1491832662802; 945.4874998124949] [221.391205120318; -22.64308775049023; 910.7108013142725] so on ... for all 35 images`

What about the unit of Translation Vector? How should I understand it ? What does its values mean?

I also tries the camera calibration app in Matlab, I set the same image but it does not show the same result?