Translation guide
A method of reducing file size by discarding some data, commonly used for images, audio, and video. In Japanese, the term is usually expressed as a direct loanword or a descriptive phrase.
The standard technical term used in computing and digital media.
The formal Japanese term for lossy compression, literally 'irreversible compression'. Used in technical documentation and academic contexts.
JPEGは非可逆圧縮の代表的な形式です。
JPEG is a typical format of lossy compression.
Loanword from English 'lossy compression'. Common in IT and multimedia contexts, especially in spoken language or less formal writing.
この動画はロッシー圧縮されています。
This video is compressed using lossy compression.
A variant of 非可逆圧縮, less common but still understood. '不可逆' also means irreversible.
不可逆圧縮では元のデータに完全には戻せません。
With lossy compression, you cannot completely restore the original data.
Explaining that compression involves data loss, often in contrast to lossless compression.
Literally 'to thin out data'. A natural way to describe the discarding of information in lossy compression.
MP3は音声データを間引いてファイルサイズを小さくします。
MP3 reduces file size by thinning out audio data.
Means 'information is lost'. Used to describe the irreversible nature of lossy compression.
非可逆圧縮では、圧縮の過程で情報が失われます。
In lossy compression, information is lost during the compression process.
Means 'cannot be restored to original'. Emphasizes the irreversible aspect.
ロッシー圧縮された画像は元に戻せません。
An image compressed with lossy compression cannot be restored to its original state.
Referring to lossy compression when talking about common file formats.
When explaining that a format uses lossy compression, simply state the format and add は非可逆圧縮です.
JPEGは非可逆圧縮ですが、PNGは可逆圧縮です。
JPEG is lossy compression, but PNG is lossless compression.
Means 'high compression ratio'. Often used to describe the efficiency of lossy formats.
MP3は圧縮率が高いので、多くの音楽プレーヤーで使われています。
MP3 has a high compression ratio, so it is used in many music players.
Lossy compression (非可逆圧縮) discards data to reduce file size, while lossless compression (可逆圧縮) preserves all original data. In Japanese, the contrast is often made with 非可逆 vs. 可逆.
可逆圧縮はデータを完全に保持しますが、非可逆圧縮は一部を捨てます。
Lossless compression retains data completely, but lossy compression discards some of it.
In casual conversation or IT settings, 'ロッシー' (lossy) and 'ロスレス' (lossless) are widely understood. You can say 'ロッシー圧縮' or simply 'ロッシー'.