SmartROI Parameters

The parameters which control the model search process are in the SmartROI params dialog box.

• The init facility will reset the variables which define the offest from the mean model to zero. (ie: setting the model a specification back to the mean).

• The total number of mark-up points defining the current model is specified by No.Points parameter. The model supports inner profile points as those points not included in the outer boundary No.Points - No.Outside.

• The Profile parameter specifies the length of the grey-level profile used for modelling.

• Location of the model (mid-point of the main axis) is specified by the tx and ty parameters. The search step used during initial localisation in the Simplex algorithm are specified by the dtx and dty parameters.

• The scale and theta parameters specify linear axis size and orientation of the current boundary profile. The search step used during initial localisation in the Simplex algorithm are specified by the dscale and dtheta parameters. Localisation is also restricted to lie withing the specified s min, s max, th max scale and orientation ranges. If the initial scale estimate is outside this range then the routine will not optimise and the location will be returned unmodified. This can often be a source of problem when using the software for the first time and should be watched out for.

• The $N$ offest shape eigen values are specified by the enumerated variables together with their search step parameters dw$N$. The effect of changing a parameter can be directly visualised by redrawing the relevant Tv.

• The initialiseation of the Simplex algorithm is determined by the Initial Search parameters. Large values will result in quicker but less precise localisation.

• The specified model will have mdl modes shape eigen vectors and prf modes grey level eigen vectors. A value of zero corresponds to mean value only.

• The maximum variation of the model away from the mean model is limited by the Search Limits.