For a project in first year uni, I implemented nearest neighbour, bilinear, bicubic, and sinc. I remember sinc looking marginally better than bicubic, but not s

For a project in first year uni, I implemented nearest neighbour, bilinear, bicubic, and sinc. I remember sinc looking marginally better than bicubic, but not significantly so for most images (which is probably why Photoshop didn't implement it at the time - I don't know if it does now). How hard it is depends on what you mean by hard. Coding these algorithms took an evening or two, but I didn't know about the gamma problem until I read the link in these comments, so it is not trivial.