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I'm having an issue with tiff files that I can't figure out. Here's an example: I open a 40 mb tiff, add one curves adjustment layer, and save the file normally (i.e., using LZW, Interleaved, IBM PC, and RLE). My file balloons when saved to 133 mb (not flattened). Again, it's a simple tiff with no previous editing and the curves adjustment layer is the only change (no resizing, nothing). Meanwhile, the onscreen Document size remains at 40/40.If I delete the single adjustment layer the file size drops to 40 mb. Why is the adjustment layer causing the file to so dramatically increase in size? Any ideas? Thanks!

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    I'm guessing here - but it sounds like adding the layer is creating three bitmaps in the file, one for the original image, one for the adjustment layer and one for the result of applying the adjustment layer. this would account for 3x40=120MB and the other 13MB may be storing masks or lookup tables or other information required by your software. – dav1dsm1th Feb 28 '14 at 20:25
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    TIFF is really just a data wrapper and whats inside can be of many different formats. Its really hard to tell what is being saved exactly, or for that matter to control what is inside it. Photoshop may reuse the curve data when its reloaded, but other apps might not. If your intention is for it to go to another app, you might just want to collapse the curve data by rerasterizing the image first. What app is your intended target and does it even understand the additional curve info as Photoshop saves it? – Octopus Feb 28 '14 at 20:27
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    what's the bits/channel in the original file and the one that you are saving? – K'' Feb 28 '14 at 21:59
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    The files are 16 bit Greyscale, but I've been trying a random mix of files to double check and this is the behavior I get from B&W or color files. I'm using PS CS5 and I have tried this with Elements 12 in it's own editor (using 8 bit files) and the result is the same. Note: these files with adjustment layers are not flattened when saved; the adjustment layer is retained. If I flatten the file, then the size decreases down to 40 +/- mb. Could this be normal behavior and I've just never paid attention to file size before due to a fast computer, lots of storage, etc.? Can someone try a test? – Michael Feb 28 '14 at 23:48
  • Adjustment layers all have a mask. The mask by default is fully white, however it is the same dimensions and bit depth as the rest of the image. So in addition to the "final result" image that is saved, you have the original layer as well as the adjustment layers mask. On top of the bitmap data, you have all the various photoshop active state and adjustment layer settings that need to be saved as well, which would account for the additional overhead. – jrista Mar 2 '14 at 0:58
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The comments have really answered the question here: The behaviour you're seeing is as you should expect.

The settings for adjustment layers alone have no equivalence in any of the TIFF content standards. TIFF does allow for vendor specific extensions and this would be an example of one but saving to a nonstandard TIFF would be pointless if nobody could open it without an Adobe application. In order to remain compatible you have to add to your source image the resulting images of the adjustment layer changes alone, the source image with changes applied and the mask. Even using PSD if you enable the compatibility options it may do something similar to the file size (I didn't check).

Given that TIFF tries to be all things to all graphics formats right from group 3 fax through to high bit depth rendering and multiple layers there is always going to be a point where following the standard introduces a significant compromise.

In this case file size is that compromise and if it concerns you then you may need to store your content in a more appropriate format such as the native Photoshop format. PSD is unlikely to be going anywhere for quite some time.

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