# How to interpolate between these two points in time?

I have an image which is positioned at (x=0, y=177, scaleW=1.0, scaleH=1.0) at say $t_0$, and I need it to be positioned at (x=35, y=110, scaleW=0.65, scaleH=0.65) at $t_1$. How do I find keyframes in between, what kind of interpolation should I choose?

scaleW and scaleH denote scaling of the image along the X and Y axis, respectively.

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## 1 Answer

You can scale each parameter linearly. The linear interpolation between $f(t_0)=f_0$ and $f(t_1)=f_1$ is

$$f(t)=f_0+\frac{t-t_0}{t_1-t_0}(f_1-f_0)\;.$$

Thus, for example, the interpolation for $y$ would be

$$y(t)=177+\frac{t-t_0}{t_1-t_0}(110-177)\;.$$

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