Notice that if alpha is equal to zero the results are the same regardless of the smoothing algorithm chosen (or not chosen).This function uses two variants of the edge smoothing:
IPPI_SMOOTH_EDGE - in this case DstRes = SrcSampled*(1-alpha) + DstExist*alpha;
IPPI_SUBPIXEL_EDGE - in this case DstRes = SrcSampled*(1-alpha);
where SrcSampled - source pixel after resizing, DstExist - destination pixel before resizing, DstRes - result destination pixel, alpha - weight of the edge pixel.
I have reopened in premier the issue that matches this forum thread. It was my understanding that the behavior change you requested was part of the 7.0 release of the product. I have not heard from you if, in fact, the 7.0 release fixed this problem for you.
Please update me on the status of this issue for you.