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Thread: Lossless formats, any preferences?

  1. #1

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    Lossless formats, any preferences?

    Are there still reasons to prefer one lossless format over another, as far as single layer images are concerned
    I'm thinking here of PNG versus TIFF. As far as I can tell, both store the same information, have lossless compression and support metadata. Also, I did run into some cases where the TIFF created by one program could not be read by the next in the flow...And TIFFs tend to grow big.

    So, any reasons to prefer TIFF over PNG would be a more honest question

    Of course, the specific formats used by photoshop and the gimp store all editing information, including layers and masks, and are specific to the program that creates them (more or less) so those are out of the game here.

    Regards,

    Remco

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    Re: Lossless formats, any preferences?

    Never occured to me to use PNG. Most of my software seems to support the format, Photoshop and my printing software both do apparently so no preference there. A small experiment this morning out of curiosity I saved an image (only one so by no means conclusive) from Photoshop in both formats in 8 bit. The PNG was decidedly smaller than the TIFF for a start which was interesting. Dragging both into my browser (Firefox) both displayed equally well but the PNG allowed me to view the image full size in the browser whereas the TIFF didn't. A TIFF saved with LZW compression was much smaller than the uncompressed version but still a little larger than the PNG. I saved the image as a 16 bit PNG which took Photoshop significantly longer to save than the equivalent TIFF which was interesting but if you work for a few hours on an image then a few seconds more to save it isn't really a biggie I guess. Both 16 bit files had the same characteristics as the 8 bit with regard to viewing in Firefox though, dragging images into Chrome brought up the Quick Player icon for the TIFF but the PNG was handled naturally by the browser.
    Comparing browser images of the 8bit PNG, the 8bit TIFF and a JPEG from Photoshop's save to web the PNG looked a bit flat in comparison to the JPEG and the TIFF which were identical as far as I could see. The original image was in sRGB so I'm guessing that wasn't the problem - seems that PNG wasn't handled quite as well by the browser.
    Looking inside the files with an editor the TIFF metadata was there in an XML format in compressed and uncompressed versions which makes it easier to extract the EXIF than the PNG version where the metadata seemed to have been compressed and was unreadable. Might be important to some people who mess around and develop their own applications (that would be me I guess).
    Apart from that I believe that most printers and publishers accept TIFF as standard, I don't know how many would take a PNG file.
    For personal use it would seem that PNG for a single layer image does have some advantages, for multi layer which I use more than anything it might be a different ball game and so for me I'll stick with TIFF. Disk space for larger files isn't that much of an issue nowadays and using one format for single layer and another for multi layer images is just another invitation to mess up somewhere in the workflow for me.
    As an aside I can't believe I devoted this ammount of time delving into this - I really need to get out more

  3. #3
    Moderator Dave Humphries's Avatar
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    Re: Lossless formats, any preferences?

    Quote Originally Posted by bambleweeney View Post
    As an aside I can't believe I devoted this ammount of time delving into this - I really need to get out more
    Ah, but we are grateful you did

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    Re: Lossless formats, any preferences?

    Can't really add much to Paul's comprehensive answer.

    PNG does support transparency which may not matter with straight photos but can be useful for producing some composite artwork, etc. It is a compressed format , although lossless, (around 50% compression I think) so that is probably why it takes longer to process.

    Some software can't display compressed Tiff images, and a few mostly older programmes may have trouble with the Photoshop format.

    However, if you are working with one of the Photoshop programmes the native format does tend to save a bit more of the editing details (layers and other adjustments) so you can always return for a simple re edit. This can also apply in some manner to a Tiff with the latest Photoshop; but with most software you have to use their own native format if you wish to retain the re editing option.

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    Re: Lossless formats, any preferences?

    Thanks a lot, Paul and Geoff.

    I was mainly interested in the difference for single layer images (output after Raw conversion, pano stitching etc.). This helped clarify things

    I'm not using photoshop, I use a Linux box with the Gimp instead, but the same holds there: use native format to keep editing info and layers intact.
    I asked as I felt a preference for TIFF here, where I had some problems with them not being readable in certain cases. PNG never gave me such problems and I could use them wherever I needed/wanted a lossless format (choice was 16-bit TIFF or 16-bit PNG).

    Remco

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    Re: Lossless formats, any preferences?

    I get the feeling that PNG is more 'native' to the Unix/Linux world than perhaps it is to Windows and so PNG just doesn't crop up in conversation with Windows users. The last Linux I had had on my desktop was Ubuntu, I found it too Windowsy (?) and trying to be too user friendly (not the hostile shell environment I'd grown to know and love ) so I removed it - how perverse is that ?

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