HALCON Extension Package Programmer's Manual

86 CHAPTER 5. HANDLING ICONIC OBJECTS AND CONTROL PARAMETERScorner (Ö¾,¾). These coordinates should be selected that way, that the filter mask is completelywithin the image when placed on any pixel inside of the rectangle. Thus, no border treatment isnecessary within Ö Ò.Ö ÓÙØ is set to all remaining pixels within Ö Ò. For those pixels an appropriate (and timeconsuming) border treatment has to be done. Fig. 5.35 shows an application of ÀÊÄÓÑÔ.Note, that the distinction of “inner” and “outer” area only refers to the image border, but not tothe border of the regions specifying the area of definition. So, it is only ensured that no memoryaccess to positions outside the image matrix can happen, but there is no guarantee that all pixelvalues covered by the filter mask when placed on pixels within Ö ÒÒÖ are defined, iftheydo not belong to Ö Ò. This means, a filter might use undefined gray values along the borderof the area of definition of the input images. The HALCON user should keep that in mind, whenapplying a sequence of filters to restricted regions of interest.5.6.4 ÀÆÙÑÇÒÒÐ×ÀÆÙÑÇÒÒÐ× (see Fig. 5.33) returns for the first input object parameter of a HALCONoperator the number of channels of the image object with number Ó ÒÜ. Thus, this routineis just a shortcut for using ÀÈÆÙÑÇÒÒÐ× as defined in Fig. 5.5 with ÔÖ ÒÙÑ ½.HALCON Extension Package Interface / 2000-11-16