Bilinear Mapping - Tutorial

The ImageJ plugin Bilinear_Mapping performs a geometric transform requiring 4 control points.

Preliminaries:
  1. Download and unzip example image: source.zip.
  2. Download and install the package Geometric Mappings.
Proceeding:
  1. Open source image:
    File > Open... source.png
     
  2. Open target image:
    File > New > Image... OK
    >notice: same image type as source image recommended
     
  3. Click Polygon selections:
    3rd button from the left
     
  4. Create a polygon with 4 sides on both images:
    create 4 points with the left mouse button and
    click the first point again to close the polygon
    projective_bilinear_polygon4
    >notice: the first point of the polygon is coloured
     
  5. Select Bilinear Mapping and choose settings:
    Plugins > GeometryMappings > Bilinear Mapping
    choose settings and press OK
    images/bilinear_settings.png
    >notice: if you don't create a new window the new image will replace the Target geometry image
     
  6. Result:
    images/bilinear.png