Yes — 圧縮されていないので BMPは読み込みや編集は速いが アップロードは遅く 保存するメタデータもありません. It is the kind of thing that explains why a file looks right in one application and wrong in another.
透明度の決定は，透明度の変更を行う段階である。 That is the step most people actually came for, and doing it after BMP を回転 rather than before it means the conversion works from the file you finally settled on.
