Grid analysis estimates the distortion from a checkerboard or thin line grid, for greater accuracy. As a general rule, if you have a grid you can use to calculate your lens distortion, you should use grid analysis to do this. To analyze a grid, do the following:
| 1. | To estimate the distortion from a grid, turn to the Grid Analysis tab. |
| 2. | Connect a grid to the LensDistortion node's Source input and select the appropriate Grid Type. |
| 3. | Press Analyze Grid to estimate the distortion and undistort the grid. |
| 4. | After analyzing a grid, you can check Align Grid to correct for perspective distortion caused by the grid not being shot square-on to the camera. |
| 5. | If you want to apply the grid’s distortion to an image input, disconnect the grid from the Source input and connect your image to it instead. |
These are the parameters on the Grid Analysis tab:
• Grid Type – Select the type of grid you want to use, Checkerboard or Thin Line grid.
• Analyze Grid – Calculate the lens distortion present. When the analysis is complete, this sets the parameters on the LensDistortion tab in order to undistort the sequence.
• AlignGrid - Check to correct for perspective distortion caused by the grid not being shot square-on to the camera. In other words, you can align the grid lines with the image edges.
• Grid Overlay – After analysis, you can choose to display the Original or UndistortedGrid lines over the image.