- response_x[0] += filter[(i + filterh / 2) * filterw + j + filterw / 2] * cos(TWO_PI * (j * fx + i * fy));
- response_x[1] += filter[(i + filterh / 2) * filterw + j + filterw / 2] * sin(TWO_PI * (j * fx + i * fy));
- response_y[0] += filter[(i + filterh / 2) * filterw + j + filterw / 2] * cos(TWO_PI * (i * fx + j * fy));
- response_y[1] += filter[(i + filterh / 2) * filterw + j + filterw / 2] * sin(TWO_PI * (i * fx + j * fy));
+ response_x[0] += filter[(i + filterh / 2) * filterw + j + filterw / 2] * cos(-TWO_PI * (j * fx + i * fy));
+ response_x[1] += filter[(i + filterh / 2) * filterw + j + filterw / 2] * sin(-TWO_PI * (j * fx + i * fy));
+ response_y[0] += filter[(i + filterh / 2) * filterw + j + filterw / 2] * cos(-TWO_PI * (i * fx + j * fy));
+ response_y[1] += filter[(i + filterh / 2) * filterw + j + filterw / 2] * sin(-TWO_PI * (i * fx + j * fy));