Rubber Sheeting (Process operations)

Select Create > Process > Rubber-Sheeting.

Creates a Displacement Item for use in rubber-sheeting. Related Topics Link IconRelated Topics

Creates a Rubber-sheet from the Displacement items specified above. Related Topics Link IconRelated Topics

Explodes a rubber-sheet into displacement items. Related Topics Link IconRelated Topics

Fitted Linear is used to:

  • transform one rectangle into another e.g. to place a pasted Metafile or bitmap
  • fitting a scanned bitmap onto existing data approximately
  • geocoding accurate third party vector data (e.g. DXF)

All displacement items are used to transform every point but the closer displacements have more effect on a particular point than the more distant ones.

If a point is exactly on the start of a displacement, it will be transformed to the end of that displacement.

Points a long way away from all displacements will be moved by the average displacement. So if the average displacement is zero, the transformation will only have a local effect.

This method is most suited to fitting a scanned bitmap onto existing data accurately.

Rubber-sheets Bitmap or Grid Items based on Displacements on another Overlay using the Linear Patch transformation.

Rubber-sheets Raster items base don Displacements on another Overlay using a Polynomial transformation.

Rubber-sheets Raster items based on Displacements on another Overlay using the Thin Plate Spline transformation.

Property

Value

Filter expression

The High X (right) pixel to crop to, as a simple value or as an expression, e.g. '123; or '_width&-Fix(Floor(0.5*_width&))'

Overlay

The High Y (top) pixel to crop to, as a simple value or as an expression, e.g. '123; or '_width&-Fix(Floor(0.5*_width&))'

Crops a bitmap.

Property

Value

Filter expression

The High X (right) pixel to crop to, as a simple value or as an expression, e.g. '123; or '_width&-Fix(Floor(0.5*_width&))'

Overlay

The High Y (top) pixel to crop to, as a simple value, or as an expression, e.g. '123; or '_width&-Fix(Floor(0.5*_width&))'

Rubber-sheets Vector items using the same Inverse Square weighted transformation.

All the start points of the displacements are triangulated. Only points which lie inside one of the triangles (or on its border) are transformed - other points are left where they are.

This method is most suited to fitting digitized vector data to known positions.