Expert: Scott Valentine - 11/15/2008

Question
Hi Scott:

Thanks for making yourself available to answer questions! This is an easy one. I have hundreds of photo masters in the JPEG format. I need to convert them to TIFFs to protect them from further degradation. Does that work?  Does a lossy JPEG become solid when saved as a TIFF? Do I need to re-scan images as TIFFs to begin with?

Many thanks!

Brian Rooney, Los Angeles

Answer
Hi Brian,

Good question! The reason JPGs degrade is because they use compression to save space. The compression method is applied every time you open and save a JPG in an editing application, so any errors are propagated and become magnified. This kind of compression is considered "lossy".

TIFF can store in a "lossless" format and in many cases has a wider color gamut than JPG files. I recommend that you start saving your images in a lossless format, which I'll explain more in a moment.

There are compression schemes for TIFF, such as LZW and even JPG. You should look into the different schemes available to your particular system and choose what works best for you. But you should be consistent!

If you are scanning from prints, definitely save in TIFF or other lossless format. However, if you are photographing new images, consider using a raw work flow (shooting in uncompressed raw format). If you have access to Photoshop and ACR, you should then convert your raw images into DNG (Digital Negative) format, which stores your images in an open format, so you can archive them without loss.

As for converting from JPG to TIFF, any changes you've made to the JPG, including compression artifacts, will freeze at that point. You can't recover that data, but at least it won't degrade further.

I hope this answers your questions - please feel free to follow up if you have further questions or would like some clarification!

-Scott