SIFT.empty constructor
SIFT.empty()
returns a new SIFT algorithm
For further details, please see: https://docs.opencv.org/master/d5/d3c/classcv_1_1xfeatures2d_1_1SIFT.html
Implementation
factory SIFT.empty() {
final p = calloc<cvg.SIFT>();
cvRun(() => cffi.SIFT_Create(p));
return SIFT._(p);
}