The techniques described in this disclosure are directed to interpolating pixel values. In some examples, the techniques interpolate a pixel value for an interpolated center pixel based on pixel values of pixel that reside on diagonal lines that are orthogonal to one another. The techniques may determine first order derivative values and, in some examples, second order derivative values to determine which pixels to utilize to interpolate the pixel values for the interpolated center pixel. The techniques may similarly determine pixel values for non-center interpolated pixels using orthogonal vertical and horizontal lines.