TIFF Compression Options: ZIP vs LZW

TIFF files are very high quality–much higher quality than most JPEGs–but the trade-off is that they’re big. You do, however, have some options for making them smaller by using compression. When it comes to TIFF, two main compression options are available–they’re known as LZW or ZIP.

Both ZIP and LZW are lossless compression methods. That means that no data is being lost in the compression, unlike a lossy format like JPG. You can open and save a TIFF file as many times you like without degrading the image. If you try that with JPG, the image quality will deteriorate more each time. So you can rest easy: using TIFF compression will not degrade your image quality.

To Use or Not to Use TIFF Compression

The reason to use compression, whether it’s ZIP or LZW, is entirely to do with filesize. You’ll end up with files that are smaller without any loss in quality, which means quicker transfers over networks and you can fit more of them on any given amount of disk or server space. If you’re a working photographer shooting hundreds or even thousands of images a day, that can add up quickly.

There are two main reasons you might not to use ZIP or LZW compression. Because they require more processing to open and close them, compressed TIFF files can be a little slower to work with. Unless you’re working with ginormous images, that’s rarely much of a problem with the speed of today’s computer processors.

A second possible reason you might not want to use ZIP or LZW compression has to do with compatibility. It is possible you might run into situations where certain software might not be able to work with compressed TIFF files. But in practice that’s pretty rare these days. Both formats have been around a long time (LZW for over 20 years and ZIP for over 10) and software developers and hardware manufacturers have had plenty of time to catch up.

There used to be a third reason not to use LZW: the algorithm was protected by patent. But that patent expired in 2003, so it’s no longer an issue for software developers to use LZW compression.

In practical use, I nearly always use compression on my TIFF files, and it’s exceedingly rare to run into a problem.

ZIP vs LZW TIFF Compression: Real-World Examples

Compression algorithms are most efficient when they can group a lot of similar data together. So images low on detail and with few tones will compress much more than images with lots of detail and lots of different tones.

For some real-world examples, I’ve run each of these four images through the various TIFF compression options. All are exactly the same dimensions and aspect ratio (4200px x 2800px). All have exactly the same amount of embedded metadata (Copyright only). All have the same color profile (sRGB).


TIFF Compression Options: ZIP vs LZW TIFF Compression Options: ZIP vs LZW
TIFF Compression Options: ZIP vs LZW TIFF Compression Options: ZIP vs LZW

  Image #1 Image #2 Image #4 Image #4
8-bit No Compression 35.3 MB 35.3 MB 35.3 MB 35.3 MB
8-bit LZW 12.9 MB 11.5 MB 22.5 MB 12.3 MB
8-bit ZIP 12.6 MB 11.6 MB 20.2 MB 12.0 MB
16-bit No Compression 70.6 MB 70.6 MB 70.6 MB 70.6 MB
16-bit ZIP 54.3 MB 53.6 MB 61.9 MB 55.3 MB
16-bit LZW 87.0 MB 76.2 MB 87.5 MB 70.9 MB

As you can see, image #2 (the photo of Australia’s Blue Mountains) compresses the most. It has the least detail and the fewest tones. The image that compresses least is image #3 (of the shrine offerings in Luang Prabang). It has the most detail and lots of different tones.

The last compression option, 16-bit LZW compression, is added mostly as a cautionary tale. There’s a reason you don’t have the option to export to that in Lightroom: LZW does not work at all well with 16-bit files and often makes them larger. So if you’re going to use compression on 16-bit files, stick with ZIP.

The Bottom Line

So the short answers are:

Should I use TIFF compression?

Almost certainly. It will make smaller files but will not degrade your image quality.

Should I use ZIP or LZW?

For 8-bit TIFF files, there’s not much in it. Both LZW and ZIP will give good results. Use either with confidence.

For 16-bit TIFF files, use ZIP.

Comments

  1. says

    What’s the difference between an 8-bit and a 16-bit photo? I am more aware of 24-bit colour schemes. Could you please explain these differences?

    • says

      It refers to the color depth that the file format supports. 16-bit images support exponentially more possible tones for each pixel than do 8-bit ones (16.7 million vs 256). A “24-bit image” can refer to two things. It can refer to yet another step up with even more possible tones, but it’s also often used to refer to an 8-bit image with three color channels (ie. Red, Green, and Blue). In most photography uses, 8-bit and 16-bit are the most common, although some cameras can shoot raw files that are 12-bit or 14-bit. In practice, and in terms of TIFF, 16-bit retains a higher quality than 8-bit and is therefore (in many cases) better for image editing and archiving. The downside is that 16-bit images have much larger file sizes than 8-bit images. Here’s a much more detailed explanation.

  2. Fran says

    Thanks for the info. I’m still a bit lost on the rest of the TIFF saving info. There is the choice of Pixel Order, Byte Order is self explanatory, Layer compression. Then there is Save Image Pyramid and Save Transparency. With all the choices, how do I know what each means and what is best to use? I have Photoshop CS6 on Windows 7, 64bit.
    Thanks for your guidance.

  3. Sam Chapman says

    I’m beginning to wonder if Adobe would prefer the TIFF format to slowly ‘die off’ and people go over to using their DNG format, which I think, is a lossless jpeg format? That would be a shame if they did manage to ‘get away’ with this, as the TIFF, is compatible with such a vast amount modern and old legacy software, I think that Adobe is trying to ‘lock’ users into their other software, via their RAW converter, as it isn’t as ‘free’ as people perceive it as being.
    To keep it updated, you also need to upgrade their software on your machine to the newest version. If Adobe, produced a ‘stand-alone’ version, where you paid a nominal fee for updates, I would be more inclined to use their RAW converter and then maybe the DNG format.

    However as things stand, and my suggestion is taken on board for a ‘stand-alone’ RAW converter, I’ll continue to save my files as TIFFs,

  4. says

    Are there any issues with compressed files being sent to a commercial printer as far as graphic design goes?

    Somewhere along the line I thought I read it could cause some issues. Maybe something to do with all the processing power needed to decompress / process a bunch of compressed large images in a magazine layout for example?

    • says

      Most of the time you shouldn’t have issues. Of course, it’s impossible to say never because there are so many possible combinations of software and hardware. I assume the type of layout you’re referring to is something like a packaged PDF with high resolution TIFFs. Depending on the size and the processing power of the computer, I can see where that might potentially become an issue, but it would really depend on the individual circumstances.

  5. Tony says

    Thanks for the detailed information! I just want to say, Adobe could go a long ways towards optimizing TIFF compression for multiple cores. I saved a multi-layer 775 MB image as a ZIP compressed TIFF, and even with four 2.8 GHz processors and 16 GB or RAM it took over 15 minutes to complete the save (but it did take the 775 MB PSD down to 331 MB). It was taking so long I opened up my performance monitor and saw that my system was using only 23% of its CPU power, and most of that was coming from one processor. There’s no reason for that, other than poor optimization on Adobe’s part. And it’s frustrating, too!

  6. says

    Thank you, I found this very informative. I can supply one reason for not using compression when dealing with TIFF or other formats for motion pictures. The decompression will take enough CPU decoding that you will not be able to playback compressed footage even when you have plenty of disk bandwidth. When using uncompressed footage your only bottleneck will be file I/O bandwidth.

  7. Sam Chapman says

    I’m rather puzzled as to why you are having problems with TIFF files with Lightroom, as the current owner/controller of the TIFF format, (since 1992) because they bought out Aldus who originally developed it, is in fact … ADOBE systems!! As a consequence, I feel that there should be no reasons whatsover why an incompatability should exist, unless of course Adobe are more interested in getting people to use their .DNG format instead …

  8. Gilley says

    Thank you for explaining this so clearly. This is one of those things I have always been curious about how much the compression really helps. Your examples are invaluable. There are many times when designing at full size around here means graphics that are 93″ tall and 40″ wide. This makes for very sizable Photoshop files. When I am ready to send the files to the printing or tradeshow company, I want to compress the files down to a reasonable size. Now I know just which compression to select when saving my files to a TIF format.

    Thanks again!

  9. Lyn Farmer says

    This is very helpful and leaves me with just one question – when exporting raw/DNG from Lightroom to tiff for external work (say, to use NIK or other plugins) when would you choose to use 8 bit and when to use 16 bit. And is there really any reason or circumstances to use the Pro-RGB colorspace?
    Thanks so much for all the helpful information and inspiration you provide

    • says

      Great question. For external edits in things like NIK or Photoshop, I always use 16-bit Pro Photo RGB. This maximizes your options with the range of colors, etc. When making changes to the image that affect anything to do with tonal range, colors, or exposure, it does have a practical effect of a better quality end product. You *could* use 8-bit for external editing, but the only reason I can think of to do so would be if you’re using an old computer with a slow processor (or memory) or that you have severe space constraints. And you *could* use Adobe RGB or even sRGB colorspace, but under normal circumstances your best bet is usually to stick with Pro Photo RGB (or Adobe RGB) for editing versions.

Comment