Replace exactly one pixel in an image and put it in another image via Swift
<p>Simply put, if I have an image, <code>I</code> and another image <code>J</code>, I want to replace the RGB value at a position <code>I(t,s)</code> and assign that pixel to <code>J(t,s)</code>. How might I do this in Core Image, or using a custom kernel?</p>

<p>This seems like it might not be an easy thing to do, considering the way Core Image works. However, I was wondering maybe there was a way to extract the value of the pixel at <code>(t,s)</code>, create an image <code>K</code> as large as <code>J</code> with just that pixel, and then overlay <code>J</code> with <code>K</code> only at that one point. Just an idea, hopefully there's a better way.</p>