Should I use JPG or TIFF for high-quality prints?
I am putting together a photo book. I shot all the photos in RAW. The prints will be 300pi on 13x11 inch glossy paper. I am laying out the pages in InDesign, which doesn't allow me to import and place RAW images.
Should I convert the images to JPG or TIFF? I know TIFF is higher quality but is it really that much better? Is the difference noticeable?
If you're using Lightroom, you may be interested in Jeffrey Friedl's InDesign workflow. (He uses PSD as the intermediary, BTW.) http://regex.info/blog/2010-11-15/1662
These two formats are different:
JPEG general info
- JPEG is used to store images on smaller disk space
- JPEG compression algorithm changes image data while converting it. Amount of change can be controlled but not its location which is always around sharp colour changes
- JPEG is primarily an RGB format
- If you saved and opened the same image several times, you may end up with an unusable image.
because for each save, the compression would generate some additional changes.Quality of the image should stay fine only if you'll use the same software with each save, always use same compression level and maybe just make some local image changes (a tiny portion of the image would get changed). In all other cases image quality will degrade.
- But: Photographic image material is especially well suited for JPEG format, because it contains lots of different colours and nuances. Since JPEG's compression changes these things they become rather invisible in the image. That's why the most prominent parts with JPEG artefacts are very sharp contrast changes as shown in the below image example.
TIFF general info
- TIFF is primarily used in press
- It's perfectly natural for a TIFF file to save image data in CMYK colour space which is used in press
- TIFF can also compress image data but uses an algorithm that doesn't change source data (lossless compression)
- TIFF format also supports alpha channel (transparency) which is also relevant in press
- If you opened and saved the same TIFF file, you'll end up with exactly the same image as source. Nothing would change in terms of image data.
If you want your images to stay as true to original as possible I'd rather go with TIFF format (with compression) because I can later open it, manipulate it, etc. and not take the risk that the resulting image (once again saved) would become useless with each save.
Since RGB -> CMYK conversion used to be bad on prepress machines it was perfectly normal to prepare all images in CMYK format and saved in TIFFs. Since I used to do prepress a couple of decades ago I feel natural using TIFF whenever preparing anything for press/print because I can easily control the outcome.
Nowadays these things are more similar yet I'd still rather use TIFF/CMYK because of lossless (saved image is same as original) compression and output control.
You can more or less always tell that a certain image was saved as a JPEG because in areas with strong contrast you can see the JPEG compression artefacts. The stronger the compression the more JPEG noise or artefacts. If you'd use maximum JPEG quality these would be minimized but still not none. So some image is still distorted due to JPEG compression.
This is an example of an exaggerated JPEG artefact. First the original and then the low quality JPEG so you can see the difference.
sidenote: both of these images are JPEGs although the original is saved with maximum JPEG quality (22.5kb) and the bad one uses lowest possible JPEG quality (20.1kb). Size difference would be significant when images are big (or even huge) and contain lots of colours and nuances. But as previously stated, it's harder to see JPEG artefacts in nice gradients than around sharp contrast transitions. And since every lens is more or less soft at pixel level there are less sharp contrast/colour transitions that would enhance JPEG artefacts.
lossy vs. lossless compression is largely irrelevant for printing, as it only really becomes a problem (giving minimum compression during saving) when doing many consecutive load-edit-save operations on a JPEG. When saving a JPEG at minimum compression for printing from a TIFF or RAW original, you'll never notice. And that's my workflow. The shop I use accepts only JPEG (and by now I think PNG). I save the NEF, work on a TIFF, and save a copy of that as JPEG for printing which gets archived for future duplication.
@jwenting: I agree. That's usually easier for print shops not to deal with clients that don't know anything about colour spaces and file formats. And JPEGs are supported by OSes by default. TIFFs are not. Anyway. It also depends what you mean by *printing*. Is it just getting your photos or is it digital offset printing or is it maybe press printing. Each of them requires different things. But for backup purposes I'd rather use either compressed RAWs or TIFFs. You could also compress your backup folder on the system level ans save your RAWs in it.
few times I've sold things for magazine or commercial use the publisher wanted JPEG as well :) I prefer uncompressed TIFF over compressed because of potential compatibility issues (the compression system for TIFF is less firmly standardised than the uncompressed format, but maybe I'm paranoid).
@jwenting: You're right about TIFF compression support (lthough LZW is quite widely supported). But if I'd be saving uncompressed TIFFs (for compatibility purposes) I'd save them in compressed folders (I don't know about Macs but Windows support this folder feature. Such folders are usually displayed in blue colour in Windows Explorer). This way my TIFFs would be uncompressed but would take similar disk space as if they were compressed.
The answer doesn't mention the important aspect of chroma subsampling. When exporting JPEG images using Gimp, for example, you can choose different settings http://docs.gimp.org/nl/gimp-images-out.html#gimp-using-fileformats-export-dialog section 1.2.2, paragraph "Subsampling". If you use 4:4:4 no subsampling is performed and JPEG 100% are perfectly suitable for printing. They are basically lossless.
This part of the answer "If you saved and opened the same image several times, you'd end up with an unusable image, because for each save, the compression would generate some additional changes" is a bit ambiguous. It is my impression that opening and closing a JPEG without doing anything to change the image, like an edit, edit does not trigger a re-SAVE. The file is just closed.