[{"data":1,"prerenderedAt":55},["ShallowReactive",2],{"tool-related-blog-ja-convert-to-jpg":3},[4,24,40],{"slug":5,"locale":6,"title":7,"description":8,"date":9,"author":10,"tags":11,"readingTime":16,"recommendedTools":17},"repeated-image-saving-jpeg-quality-loss-guide","ja","画像を何度も保存すると画質が落ちるのはなぜ？","ファイルコピーと再エンコードを区別し、JPEGの繰り返し圧縮やPNG変換の限界、原画像を残して最終出力を確認する方法を解説。","2026-09-15","DocCrunch Team",[12,13,14,15],"画像の繰り返し保存","JPEG画質劣化","画像の再エンコード","画像圧縮",5,[18,20,22],{"slug":19},"image-compress",{"slug":21},"convert-to-jpg",{"slug":23},"image-resize",{"slug":25,"locale":6,"title":26,"description":27,"date":28,"author":10,"tags":29,"readingTime":16,"recommendedTools":34},"transparent-images-white-background-edge-halos-guide","透明画像の白い背景・白い縁：原因と確認方法","ビューアーの背景、透明情報の消失、輪郭の色残りを区別。PNG・JPGの制約と、背景除去・書き出し・縮小・圧縮後の確認方法を解説します。","2026-09-14",[30,31,32,33],"透明画像","PNGの白い背景","切り抜きの白い縁","背景除去",[35,37,38,39],{"slug":36},"image-remove-bg",{"slug":21},{"slug":23},{"slug":19},{"slug":41,"locale":6,"title":42,"description":43,"date":44,"author":10,"tags":45,"readingTime":16,"recommendedTools":49},"jpg-png-webp-avif-how-to-choose","JPG・PNG・WebP・AVIFの選び方","JPG、PNG、WebP、AVIFを画質・容量・透明背景・互換性で比較。形式変換と圧縮、サイズ変更の違いや、ローカル変換後の確認点も解説します。","2026-09-09",[46,47,48,15],"画像形式の選び方","JPG PNG WebP AVIF","画像形式変換",[50,51,52,54],{"slug":21},{"slug":23},{"slug":53},"image-crop",{"slug":19},1789443075166]