Generate grid🔗

Generates a set points that uniformly covers the pixel grid of an image. With an iteration this tool can be used to apply an operation to sub-images.

To split an input image into fixed-size pieces, iterated grid corners can be used as an input to :doc:pixel-to-world coordinate transform <PixelCoordinatesToWorldTool> followed by cropping. To apply an operation to sub-images without cropping one can connect the iterated grid corners as the frame input for many tools such as histogram.

Inputs🔗

  • image: The image to cover with a grid.

  • gridSpacing: The horizontal and vertical spacing between points in pixel coordinates.

  • gridPosition: Specifies how the grid should be positioned.

Outputs🔗

  • corners: The coordinates of the upper left corners of each grid cell in pixel coordinates in row-major order. A N-by-2 matrix. Note that due to perspective and non-linear lens distortions the points may not be uniformly spaced in world coordinates.

  • gridSize: A 1-by-2 integer matrix that contains the number of cells in the grid (width, height).

enum GridPosition🔗

Different ways of positioning the grid.

Values:

enumerator FitInImage🔗

Make sure each cell fits in the image completely.

If the size of the image is not a multiple of gridSpacing, leave equal top/bottom and left/right margins. If the input image is smaller than gridSpacing, this technique produces an empty set of points.

enumerator CoverWholeImage🔗

Make sure every pixel in the image is in one of the cells.

If the size of the image is not a multiple of gridSpacing, the top/bottom and left/right cells exceed image boundaries by an equal amount.