{"id":21374,"date":"2016-05-04T15:25:32","date_gmt":"2016-05-04T15:25:32","guid":{"rendered":"http:\/\/why_jpeg_is_like_a_photocopier"},"modified":"2026-03-11T17:36:20","modified_gmt":"2026-03-12T00:36:20","slug":"why_jpeg_is_like_a_photocopier","status":"publish","type":"post","link":"https:\/\/cloudinary.com\/blog\/why_jpeg_is_like_a_photocopier","title":{"rendered":"Why JPEG is like a photocopier"},"content":{"rendered":"

Generation loss, a term originally rooted in the world of analog media, refers to the quality degradation that occurs when audio or video is reproduced. In the context of analog tape and audio transfers, each copy of an original source is a new generation, and with each transfer, the quality inevitably declines. This degradation in analog media is due to factors like signal loss, physical abrasion, and electronic noise, characteristics distinct from digital generation loss.<\/p>\n

Interestingly, this concept of generational decline, though historically associated with analog formats, has parallels in the digital realm, particularly in digital imaging.<\/p>\n

If you make a copy of a copy of a copy, the quality will deteriorate with every \u2018generation\u2019. This problem is called \u2018generation loss\u2019. It is not difficult to understand why this happens with actual copier machines. Scanning and printing are not perfect, being based on noisy sensors and physical paper and ink, and the resulting noise will tend to accumulate.<\/p>\n

Digital images should theoretically not have this problem: a file can be copied over and over again, and it will still be bit-for-bit identical to the original.<\/p>\n

However, lossy image formats like JPEG can behave like photocopiers. If you simply copy a JPEG file, nothing changes, but if you open a JPEG file in an image editor<\/a> and then save it, you will get a different JPEG file. The same happens each time an image is uploaded to, say, Facebook or Twitter: the image is re-encoded automatically (in the case of these two social networks, with a relatively low quality setting, to save on storage and bandwidth). Some information is lost in the process, and compression artifacts will start to accumulate. If you do this often enough, eventually the image will degrade significantly.<\/p>\n

In this article we\u2019ll take a deeper look at the generation loss of JPEG and other lossy image formats. We\u2019ll explain what causes it, and how it can be avoided.<\/p>\n

What happens if you save a JPEG over and over again?<\/h2>\n

This is what happens if you re-encode a JPEG image many times:<\/p>\n