SignDoc SDK (Java)  5.0.0
Coordinate Systems

SignDoc SDK uses three distinct coordinate systems:

  • document (page) coordinates
  • image (canvas) coordinates
  • capture (tablet) coordinates

The origin of the document coordinate system is in the bottom left corner of the page (as rendered, that is, taking rotation of PDF pages into account). Points having positive X coordinates are to the right of the origin, points having positive Y coordinates are above the origin.

For PDF documents, the origin is in that corner of the intersection of the CropBox and the MediaBox of the page that corresponds to the bottom left corner of the image that would be rendered for that page. The units are 1/72 inch (even if UserUnit is not 1).

For TIFF documents, the origin is in the bottom left corner of the page, the unit is one pixel (see de.softpro.doc.SignDocDocument.getResolutionX(), and de.softpro.doc.SignDocDocument.getResolutionY()).

The origin of the image coordinate system is in the upper left corner of the image. Points having positive X coordinates are to the right of the origin, points having positive Y coordinates are below the origin. The unit is one pixel.

The origin of the capture coordinate system is in the upper left corner of the capture device; X coordinates increase to the right, Y coordinates increase downwards. Note that this coordinate system differs from the coordinate system used by ISO 19794-7. Units depend on the resolution of the capture device.