English: Visual comparison of convolution, cross-correlation and autocorrelation. For the operations involving function f, and assuming the height of f is 1.0, the value of the result at 5 different points is indicated by the shaded area below each point.
Note that placing f♦g next to g∗f, instead of next to f∗g facilitates comparing the 5 snapshots below the graphs. They are identical sets, except for the orientation of function f, as denoted by the little bump on its left-hand corner. But since f is symmetric, the orientation does not matter, which explains why g∗f and f♦g are identical in this example.