[wtallis]

I certainly didn't mean to imply that the signal processing perspective was untenable with the modern world of actually-rectangular pixels, but what you describe is really a post-hoc shoehorning of square-pixel thinking into the signal processing framework. And you still haven't accounted for pixel-oriented font hinting or pixel-first design of bitmap fonts and graphics that gives leeway to the underlying shapes in order to maximize legibility when rendered onto a pixel grid. The signal processing perspective can offer some valuable insight, but it's a pretty bad choice as an overriding mode of thought for computer graphics.

(And I'm not the author of the article.)

[jtxx000]

Sure, for bitmaps fonts or pixel hinting the signal processing framework doesn't provide much insight. However, the word aliasing itself refers to a concept from signal processing, and in my opinion, it's easiest to think of anti-aliasing from the signal processing perspective.

For example, look at the images in [1] (also a rather old paper). The box filter results (i.e. where the pixel value is set to the average of covered area) are less than ideal.

[1] Quadrature Prefiltering for High Quality Antialiasing: http://www.cs.northwestern.edu/~jet/Publications/quadfilt95....