Example: Fix alpha channel in doc/ex/coalesce.rb
Fix
@@ -43,7 +43,7 @@ srand 1234
offset.x = x * button.columns
offset.y = y * button.rows
button.page = offset
- button.alpha(Magick::ActivateAlphaChannel)
+ button.alpha(Magick::SetAlphaChannel)
cells << button
end
