Camera Distortion Calibration

## Camera Distortion Calibration

Calculate the distortion of the camera and generate calibration type data storage. This module is only used to generate calibration and store it with global variables. Use requires referencing by **Image Correction** module.

## Module Principle

![](/media/202601/2026-01-16_155814_8986340.8997417189483791.png)
Calculate the camera's distortion correction matrix by inputting photos of the calibration board at different height positions.
Calculation methods include division model: only calculate one unknown kappa; polynomial model: calculate 3 unknowns (barrel distortion K1, K2, K3). You can choose a more accurate model according to the actual situation.
This module only calculates the camera's barrel distortion and pincushion distortion. Camera tangential distortion requires the use of **Perspective Distortion Calibration** module.
Tangential Distortion:
![](/media/202601/2026-01-16_160338_4015770.7177420841517493.png)

Select a folder in **Image Path**, and the captured images are stored under the folder. The requirement is photos of the same calibration board at different positions and different heights. The number of images is best to be more than 5.
![](/media/202601/2026-01-16_155907_1150400.3978216374040696.png)
## Usage Scenarios
Large field of view camera, shooting objects will have distortion, and the deformation around the field of view is relatively large. This algorithm is only suitable for distortion caused by camera lens, and cannot correct distortion caused by shooting plane not being horizontal.

## Usage Method

### Predecessor/Successor Modules
Only one Camera Distortion Calibration module is needed.
![](/media/202601/2026-01-16_160234_6796840.9126126088657518.png)

## Parameter Configuration Description

![](/media/202601/2026-01-16_152544_4869090.5812027012070908.png)
【Calculation Method】Division Model: Only calculate one unknown kappa.
Polynomial Model: Calculate 3 unknowns (barrel distortion K1, K2, K3). You can choose a more accurate model according to the actual situation.
【Calibration Group】 Select the corresponding coordinate system group, and the calibration data will be recorded in the calibration file under the coordinate system group. The coordinate system group must be set in the coordinate system calibration in the global data management.
【Calibration File】 Select the calibration file under the corresponding coordinate system group, and the calibration data will be recorded in the file. (The calibration file must be set in the coordinate system calibration in the global data management. First add the coordinate system group, then drag the camera and robot to the window under the corresponding coordinate system group, select the connection line to connect the two icons, and the calibration file can be generated)
【Image Path】Select a folder, and the captured images are stored under the folder. The requirement is photos of the same calibration board at different positions and different heights. The number of images is best to be more than 5.
### Calibration Board
Black and white grid calibration board:

![](/media/202601/2026-01-16_162735_5148730.3703601986727093.png)
Symmetric circular grid:

![](/media/202601/2026-01-16_162814_0898930.3236009051907831.png)
Asymmetric circular grid:

![](/media/202601/2026-01-16_162857_9477640.23725306917481037.png)
【Size】Input the number of horizontal and vertical corner points of the calibration board. (Grid / Dot count - 1)

## Output Description
Error Code: -1: Image points not obtained. Check if image points are clear. Check if calibration board size is input correctly. (Count is corner point count is grid/dot count - 1.)
Error Code: -2: Valid image not obtained. Check image format, check path. (Path cannot have Chinese.)
## Precautions
1. Image path cannot have Chinese.
2. The captured calibration board images require photos of the same calibration board at different positions and different heights. The number of images is best to be more than 5.
3. The size input is the number of horizontal and vertical **corner points** of the calibration board. (Corner point count = Grid/Dot count - 1)
4. This module is only used to generate calibration and store it with global variables. Use requires referencing by **Image Correction** module.

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Click here to jump to the corresponding Chinese manual page: [Camera Distortion Calibration](/doc/55)