Yes, the fastest way is the loop with scanline:
var px: pbyte;
...
for row := 0 to ImageEnView.IEBitmap.Height - 1 do
begin
px := ImageEnView.IEBitmap.Scanline[row];
for col := 0 to ImageEnView.IEBitmap.Width - 1 do
begin
...replace ImageEnView.IEBitmap.Pixels_ie8g[] with "px^"...
inc(px);
end;
end;