# Is there any OpenCV or IPP equivalent for this function?

I have this `interpolate`

function taken from this code which I want to optimize:

```
bool interpolate(const Mat &im, float ofsx, float ofsy, float a11, float a12, float a21, float a22, Mat &res)
{
bool ret = false;
// input size (-1 for the safe bilinear interpolation)
const int width = im.cols-1;
const int height = im.rows-1;
// output size
const int halfWidth = res.cols >> 1;
const int halfHeight = res.rows >> 1;
int dim = res.rows * res.cols;
float *out = res.ptr<float>(0);
const float *imptr = im.ptr<float>(0);
for (int j=-halfHeight; j<=halfHeight; ++j)
{
const float rx = ofsx + j * a12;
const float ry = ofsy + j * a22;
#pragma omp simd
for(int i=-halfWidth; i<=halfWidth; ++i)
{
float wx = rx + i * a11;
float wy = ry + i * a21;
const int x = (int) floor(wx);
const int y = (int) floor(wy);
if (x >= 0 && y >= 0 && x < width && y < height)
{
// compute weights
wx -= x; wy -= y;
// bilinear interpolation
*out++ =
(1.0f - wy) * ((1.0f - wx) * imptr[rowOffset+x] + wx * imptr[rowOffset+x+1]) +
( wy) * ((1.0f - wx) * imptr[rowOffset1+x] + wx * imptr[rowOffset1+x+1]);
} else {
*out++ = 0;
ret = true; // touching boundary of the input
}
}
}
return ret;
}
```

I'm not the image processing guy and I'm really struggling to perform the equivalent using the opencv implementation. This is crucial for my project since the function above is incredibly time consuming.

Please help.

It seems you can seriously speedup your own code by replacing all the constructions as im.at<float>(x,y) by the pointers arithmetics equivalent.

@pi-null-mezon I'm sorry, it was already optimized on that point, I updated the question. Can you help me in some other way? I'm seriously stucked on this, using an equivalent function could help me so much