# 表情変更

「表情変更」プロンプトとは？

表情変更プロンプトは、写真に写っている人物の顔の表情だけを AI で別の表情に変える画像編集指示です。集合写真で一人だけ目を閉じてしまった、緊張で表情が硬くなってしまった、せっかくの記念写真で笑顔になれなかった、など「撮り直しが効かない場面」での救済として需要があります。 無表情→笑顔：`Change the facial expression in the uploaded photo from a neutral expression to a natural, gentle smile with slightly raised cheeks and a subtle softening of the eyes. Keep the eyes open and looking in the same direction. Preserve the face shape, age, and identity of the person exactly.` 目閉じ→目開け：`The person in the uploaded photo has their eyes closed. Change the eyes to be naturally open, looking softly toward the camera. Match the eye color and shape to what would be consistent with the person's age and ethnicity. Do not change any other facial feature.` 硬い表情→自然：`Soften the tense expression in the uploaded photo into a relaxed, natural look. Slight relaxation of the jaw, subtle warmth in the eyes, no exaggerated smile. Maintain the person's identity and overall composition.` 共通ルール：(1) 同一性厳守：`preserve identity, age, and key facial features`、(2) 過剰変更の防止：`do not transform the face beyond the requested expression change`、(3) 自然さ：`keep the result photorealistic, no AI-rendered or doll-like appearance`、(4) 周辺要素の保持：`do not change hair, clothing, or background`。Gemini 2.5 Flash Image を第一推奨。