「顔加工」プロンプトとは？
顔加工プロンプトは、写真に写っている顔の表情・角度・細部を AI で調整する画像編集指示です。表情を「無表情から自然な笑顔へ」「目を完全に閉じている→開いた状態へ」、顔の向きを「真横から少し正面寄りへ」など、本人の同一性を保ちながら使いやすい写真に整えます。 表情変更の指示文：`Change the facial expression in the uploaded photo from a neutral expression to a natural, subtle smile. Keep the eyes shape, nose, lips outline, and overall facial structure exactly the same. Avoid an unnatural or exaggerated smile. Maintain the person's identity.` 角度補正の指示文：`Slightly rotate the face in the uploaded photo to face more toward the camera (about 10-15 degrees). Keep the original lighting direction and shadows consistent. Do not change the face shape or features.` 赤目補正：`Fix the red-eye effect in the uploaded photo while keeping the original eye color, shape, and natural reflections.` 品質を保つ 3 ルール：(1) 同一性保持：`preserve the person's identity, age, and key features`、(2) 過剰変更の禁止：`do not transform the face beyond the requested change`、(3) 自然さの強調：`keep the result photorealistic, no cartoonish or AI-generated look`。Gemini 2.5 Flash Image が第一推奨。