Definiens Developer 7 - PCI Geomatics

Definiens Developer 7 - Reference Book3 Algorithms ReferenceExampleFigure 4: Result of chessboard segmentation with object size 20.Object SizeThe Object size defines the size of the square grid in pixels.NoteVariables will be rounded to the nearest integer.Level NameEnter the name for the new image object level.Precondition: This parameter is only available, if the domain pixel level is selected in theprocess dialog.Thematic LayersSpecify the thematic layers that are to be considered in addition for segmentation.Each thematic layer that is used for segmentation will lead to additional splitting ofimage objects while enabling consistent access to its thematic information. You cansegment an image using more than one thematic layer. The results are image objectsrepresenting proper intersections between the thematic layers.Precondition: Thematic layers must be available.If you want to produce image objects based exclusively on thematic layer information,you can select a chessboard size larger than you image size.3.2.2 Quad Tree Based SegmentationSplit the pixel domain or an image object domain into a quad tree grid formed by squareobjects.A quad tree grid consists of squares with sides each having a power of 2 and aligned tothe image left and top borders is applied to all objects in the domain and each object isquad tree basedsegmentation16