JPEG, TIFF, PSD, Successive Save, Save As, and more how?
There’s often confusion about what makes a JPEG and other files degrade, so I though it was time to do a real world test. First let me say that simply copying, or viewing a file does not cause any degradation as some believe. If you copy and paste a file it’s simply a bit for bit copy, and there’s no loss.
When you open, and then re-save a file is when things usually change. When you do this, even if you save at the highest quality JPEG settings you have still uncompressed the file, and it gets re-compressed when you save again. Unless or course your using an uncompressed file format to start with.
So how bad is a file damaged each time you successively save it. Well lets just say you should keep your originals folks. Below we’re going to look at the same image submitted to various torturous conditions. You can then judge for yourself.
Actual images were 700px wide. Click any version to see full size, or download all the images (plus a few extras) to compare them. Images that were opened and saved with “Save As” rather than “Save” commands are noted as such. If you want to join the discussion beyond comments here is the forum topic on this.
Original File.

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