// 'targetX' and 'targetY' attribute
int[] targetXY = convertTarget(filterElement, orderXY, ctx);
// 'edgeMode' attribute - default is 'duplicate'
PadMode padMode = convertEdgeMode(filterElement, ctx);
// 'kernelUnitLength' attribute
double[] kernelUnitLength = convertKernelUnitLength(filterElement, ctx);
// 'preserveAlpha' attribute - default is 'false'