Increasing JPEG filesize without losing quality

Discussion in 'Digital Darkroom' started by anton_bredell, Jul 23, 2006.

  1. I am currently using Rawshooter essentials to convert RAW files to JPEG.The
    resulting JPEG's are 3.1MB in size.After converting them to JPEG, I use
    Photoshop7 to retouch if needed.I am submitting to a site that require 6MB and
    larger JPEG's.How do I go about increasing the JPEG filesize without losing
    quality? Is this the best workflow to use? Do I lose image quality each time I
    work on and resave a foto? Will appreciate any feedback. Thank you
     
  2. You cannot increase a raster image's size without loosing something, unless perhaps it's a subject with no luminance changes, flat colors, all within the scope of a GIF file (for the web). It is a matter of physics, of fact.

    The best you can do is to interpolate in 10% increments with very modest unsharp mask applied at certain stages. In your case the increase is not severe so try that. I forget if PS7 has actions, but if it does, use them and be happy.

    Just don't waste any money on Fractal Magic and similar theftware.
     
  3. Anton, if you need to save, do edits and resave, etc. then jpeg will lose some quality each time. You are better off converting to a TIFF file, doing all of your editing and saving/resaving in that format and then converting to jpeg as the last step if you want to send smaller files to your lab or whatever. Incidently, if you feel the need to resize them to bigger files to send to your lab for printing, I personally wouldn't bother. I would just sharpen appropriately and trust the lab's printer to do the interpolation for you. In my experience they have always done as good or usually BETTER job than I could do myself of resizing.
     
  4. If you discared the original RAW files, as you seem to be implying,
    you'll find that the Lanczos filter (free in ImageMagick or IrfanView)
    does a better job of upsampling than Photoshop, even the 10% at a time
    trick Pico recommends. Hopefully you saved high quality JPEG with
    1x1 chroma subsampling, because those up-res fairly well.

    In the future, save your frickin' RAW files!
     
  5. Is the 6 Mb requirement compressed or uncompressed? If you look at a jpeg file size on disk, then you're looking at the compressed size. However, if you open the file in (say) Photoshop, then the software decompresses the file and reports the uncompressed size, which will be a lot larger. Check with the site that you're submitting to.<p>
     
  6. If you HAVE to submit the files as JPEGs, then lower the compression rate. I usually use Paint Shop Pro, which allows me to change the compression rate when converting a file into a JPEG. I assume Photoshop does as well since it has more features than PSP. You could also increase the # dots per inch/cm. It would be best to do either of these things the 1st time you are saving the file as a JPEG, since as another person above noted, you do lose data every time you re-save a file as a JPEG.
     
  7. JPEG is not a good file format to use for an intermediate file; if you have to save a file from your RAW converter before opening it in your editor, save it in a file which does not use lossy compression, and if at all possible, it would be wisest to save it at 16 bits. If you save your intermediate files using lossy compression (which is what JPEG uses), then yes, you lose image quality each time you go through an open-work-save cycle.
    I don't shoot for any sites which are dumb enough to set such a minimum file size so I haven't had to upsize files to meet such an arbitrary requirement. But others have given you some suggestions on how best to resize so hopefully you'll be OK there.
     
  8. .

    I think that you might be misunderstanding their requirement.

    A 6mb JPG means nothing since JPG file sizes depend on too many variables to be predictable, like mage content (complex or simple, sharp or unsharp), image size (pixel dimensions), and compression ratio - all could ve vastly different to make a srotage file size of 6mb.

    I think they mean 6mp capture, meaning

    ~3,072x2,048 pixels = 6,291,456 pixels = 6mp for film scans at a 1.5:1 aspect ratio, or

    ~2,929x2,148 pixels = 6,291,456 pixels = 6mp for typical non-35mm digital capture of 4:3 aspect ratio, or

    for square film = 6mp^2 = ~2,509x2,509 pixels = 6,295,081 pixels = 6mp.

    Maybe they mean 6mb after expansion on screen, and in Adobe Photoshop, it tells your the "expanded" file size regardless of the original JPG compression, and it's 3x the pixels dimension since it really has 3 pictures inside - one red, one green and one blue!

    35mm scan at 1.5:1 aspect ratio then = 1744x1183 pixels = 6mb

    digital 4:3 aspect ratio = 1673x1255 = 6mb

    square = 1449x1449 = 6mb

    It all depends on thier meaning of 6mb expanded file size on screen in 8-bit color, or 6mp camera is required as a minimum capture? Tell us more.

    And JPG is a final output format never to be re-edited again (a crime and a sin to edit a JPG and resave as a JPG), especially by you. You should work in TIF and only convert to JPG once before sending the file out at 100% (or 0% compression) for stock, and anything lower for display only, like 65% to 85% for web display, but of course, web display also expects resizing down to only 1,024x wide or less, of course making smaller storage files.

    Let us know some specifics of the place your're sending them to so we can read the requirements and help you interpret them better.

    Or ask them to explain and tell us waht they say - don't make us speculate when you don;t know enough to quote and understand their entire requirements!

    Click!

    Love and hugs,

    Peter Blaise peterblaise@yahoo.com Digital Photographer http://www.peterblaisephotography.com/
     
  9. well there is a great program called Geniune Fractels thats a program that would definitely
    work for you
    Tony
     
  10. .

    Ahh ... we need to wait for Anton to get back to us with answers to our questions - what are the specifics (links?) of the requirement, as "6MB JPG" seems to be a misunderstanding.
     
  11. Spearhead

    Spearhead Moderator Staff Member

    well there is a great program called Geniune Fractels thats a program that would definitely work for you
    Genuine Fractals does not in any way improve on the methods given above, and it costs a lot of money. In addition, once you have paid a lot of money to them, you are on your own. I had installation problems and despite numerous emails and phone calls, never got a response from support. Much easier and cheaper to use the PS, PSP or Irfanview methods.
     
  12. Thanks for all the replies. I am submitting to an image library called PhotoLibra.com. They require one of the following:
    JPEGs at max. quality (minimum 6MB at 300dpi+)
    or TIFF files (minimum 12MB) (I can find no more info on their website-they referred me to Photo.net)

    After converting raw files to Tiff, and editing The Tiff files In Photoshop7, I end up with Tiff files of 46MB (too big for me to download within reasonable time on a dialup connection) I need to convert them to JPEGS. There is no jpeg option under �save as� in PS7. I then go to �save for web�, where I save as JPEG at Max quality. The resulting image is automatically saved at 72 dpi. Is there a way to change the dpi setting before saving? And still the resulting image file size is only 3MB! Can you see why I am on the edge? Thanks for all the inputs.
     
  13. Anton,

    http://www.fotolibra.com/about/imagesizes.php

    I don't see anything about minimum sizes. Maybe it's something you find out after joining. Odd, if true. Maximum filesizes I could understand...

    The filesize of a jpeg depends on a number of things, content, for example. Everything else being equal, a jpeg of a crowd at an event is likely to have a larger filesize than a shot of a flower on a plain background.

    --

    Don E
     
  14. "I can find no more info on their website-they referred me to Photo.net"

    Anton,

    If they don't know what they mean, how should we?

    Where is all this minimum filesize stuff published? Where did you get that information?

    When they referred you here, what did you ask them? "How do you resize files?" If so, it was a good referral.

    Did you ask them: "Is there a minimum filesize for jpegs uploaded to fotolibra.com?" and they referred you here, there's been failure in communication.

    --

    Don E
     
  15. If your TIFF files are ending up at 48MB, you are probably working in 16 bit. Convert to 8 bit first. If necessary you can use Image/Image Size to make the file size smaller than the 24MB it will be after conversion to 8 bit. Now you will be able to Save As and JPG will be an option. Use level 10 or higher JPG, they ask for a minimum file size, not a maximum. Never use Save For Web, it does bad things to your images! Be sure to save your original, 16 bit TIFF image (and/or your RAW files) for your own archives. Sizing and conversion to JPG should be the very last step in your workflow, because every time you work on a JPG file and save it again, you lose information.

    Even if your 48 MB file is already 8 bits, you can downsize it (or not), and then save it as JPG. I used Photoshop 7 for years, if JPG is not an option in Save As, there is something else you have not done. Are you flattening the image before you try to save? You cannot save layers as JPG.
     
  16. .

    Let's stop speculating and keep ferreting out what http://www.fotolibra.com/ REALLY requires or recommends.

    I just joined - free.

    =====

    From http://www.fotolibra.com/

    "... Select the number of pictures you wish to upload, choose TIFF or JPEG image files (min. 1MB) from your hard disk or CD then add captions, categories, keywords & dates.

    Try to upload 300dpi images between 6MB and 48MB ..."

    From http://www.fotolibra.com/support/?id=26

    "... RAW

    fotoLibra accepts TIFF and JPEG file formats, not RAW. What we need and want from Members are 300dpi TIFF files between 48MB and 100MB, using Adobe 1998 RGB as the working RGB profile.

    Shoot in RAW, convert to TIFF, upload TIFFs with LZW compression if you like.

    Smaller photos sometimes sell, but faced with two choices the buyer will always go for the bigger picture ..."

    =====

    So, I recommend uploading TIFs at full original size after tweaking.

    DPI is meaningless in a digital file, so set it to 300dpi to make subsequent idiot$ happy.

    When saving AS select FORMAT and select JPG IF you want JPG, but why loose valuable image data? Save as TIF and be happy knowing you're saving your entire image, not just part of it (as JPG does - JPG NEVER saves your entire original file)!

    Saving for web of COURSE will set 72dpi, which is meaningless.

    'nuf said?

    =====

    Anton wrote: "... I am submitting to a site that require 6MB and larger JPEG's ..."

    I didn't thing Anton had it right!

    Click!

    Love and hugs,

    Peter Blaise peterblaise@yahoo.com Minolta Rokkor Alpha DiMage Photographer http://www.peterblaisephotography.com/

    =====

    More from http://www.fotolibra.com/support/?id=28

    Selling Pictures

    fotoLibra offers photographers and copyright owners three ways in which to profit from their pictures.

    Our Trial Offer lets photographers test out the system prior to joining as Full or Platinum members. Up to five free images can be uploaded; these are then displayed and offered for sale to professional picture researchers. Rights sales fees are split 50/50.

    Full Membership provides up to 3GB of space to store and market hundreds of images. It costs just �6 (about �8.70 / $10.38) per month and is paid quarterly via our secure server. Sales fees are also split 50/50.

    Platinum Membership ensures that the most extensive image collections can be safely stored and marketed, providing unlimited secure storage for only �15 (about �21.80 / $26.05) per month, again paid quarterly. Rights sales fees are split 60/40, and every week the work of one of our Platinum members is featured on fotoLibra�s home page via the �Photographer of the Week� link.

    We make the process as easy as possible for you. Your Membership comes in three month packages, so your account is billed every quarter. You can cancel whenever you want by giving thirty days� notice in writing � there�s no continuing obligation.

    Photographers upload their images, in which they retain copyright at all times, on a non-exclusive basis, leaving them free to offer those pictures for sale on their own website or through another picture library should they so wish. You can also market your images as either Rights Managed or Royalty Free.

    =====

    More at http://www.fotolibra.com/about/faq/

    Including:

    "... What image size, format and resolution should I upload?

    fotoLibra only accepts TIFF and JPEG files. Digital cameras create JPEGs and these should be uploaded at 12 or Maximum resolution.

    Scanned images can be uploaded as TIFFs or JPEGs, without compression.

    Please upload RGB images, not CMYK.

    When scanning transparencies, set the image size to 200% and scan at 1200dpi. Royalty Free images should be 48MB or above. Uploaded pictures less than 5MB in size will not be allocated a DOI ..."

    "... How I can verify the DOIs?

    The DOI is simply a string of numbers automatically embedded in your digital image file which will contain references to the captions and keywords YOU as a Member have uploaded. It gives out exactly what you give in. More info at http://www.doi.org ...

    From http://www.doi.org

    "... Welcome to the DOI� System

    The DOI system is for identifying content objects in the digital environment. DOI� names are assigned to any entity for use on digital networks. They are used to provide current information, including where they (or information about them) can be found on the Internet. Information about a digital object may change over time, including where to find it, but its DOI name will not change.

    The DOI system provides a framework for persistent identification, managing intellectual content, managing metadata, linking customers with content suppliers, facilitating electronic commerce, and enabling automated management of media. DOI names can be used for any form of management of any data, whether commercial or non-commercial.

    The system is managed by the International DOI Foundation, an open membership consortium including both commercial and non-commercial partners, and has recently been accepted for standardisation within ISO. Over 20 million DOI names have been assigned by DOI system Registration Agencies in the US, Australasia, and Europe.

    Using DOI names as identifiers makes managing intellectual property in a networked environment much easier and more convenient, and allows the construction of automated services and transactions.
    To learn more about DOI names, see the Overviews, and begin with the Introductory Overview and Introductory Slide Presentation. The Factsheets discuss key topics about the system. For the most complete description of all aspects of DOI system technology and policy, consult the DOI� Handbook ..."

    =========

    Geesh - so much for simply being PHOTOGRAPHERS, now we have to translate high tech jargon become high tech masters, too!

     

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