Peter wrote in part:
He also chose not to join the imagist movement.
I assume that you mean that Pound did not continue with the Imagist movement
after that school was taken over by Amy Lowell. He referred to the imagism
of Amy Lowell as Amygism. Amy, like McLuhan had missed the point of Imagism
(big I) and thought it was about colorful metaphoric depictions of things.
Pound once remarked that the Image is not a thing.
Pound Imagism (big I) became Vorticism which is basically the original
Imagism expanded to include arts other than poetry and, in the case of
poetry, more dynamic charged language. "The Game of Chess" is usually cited
as probably Pound's program poem for Vorticism.
For a short but eminently authoritative discussion of Imagism (big I) and
Vorticism see Hugh Witemeyer's "The Poetry of Ezra Pound: Forms and Renewal
Witemeyer discusses Imagism (big I) on page 32-36 and Vorticism on page
36-39. The Ideogramic method is discussed 39-41.