I have 200x380 input image and coordinates (63,146) where (0,0) is top-left:
I rotate about the centre some amount of degrees and expand the "canvas" to avoid cropping resulting in larger output image:
How do I calculate the relative position of point after rotation, with respect to the new larger image?
I'm roughly familiar with how to get the point with respect to the original size but I'm not sure how to transform the calculated new point to fit it in the new image. Red dot is failed attempt of implementing solution transforming the images centre to the 0,0 used in the rotation transform:
My math literacy is not fantastic and I apologise for misusing any terms.