How to "restore" PNG files converted from JPEG format?

Discussion in 'Graphics & Multimedia' started by cc2365, Jan 11, 2015.

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  1. #1
    Hi. I came across some PNG files which, judging from its compression artifact, were saved as JPEG files at first and converted to PNG files afterwards.

    Since these PNG files are very space-consuming (and their quality is bad), I want to convert them back to JPEG format. As far as I know, this will cause additional compression on the images, making its quality even worse. So how can I, while reducing file size, keep the quality loss minimal? It there any software (free or paid) good for this purpose? Any advice will be appreciated!

    :confused::confused::confused:
     
    Last edited: Jan 11, 2015
    cc2365, Jan 11, 2015 IP
  2. Norebbo

    Norebbo Active Member

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    #2
    Yes, there will be additional compression if you save back to JPG. Your best bet is to save it with at the highest quality, which may or may not reduce the file size much - just zoom in on the file in Photoshop, go to File > Save As..., select JPG, and then your image will update in real time as you change the quality settings (so you can see what you're going to get).

    Try using the Save for Web option as well, and select 8bit PNG - that should reduce the file size drastically without much loss of quality (depending on the image).
     
    Norebbo, Jan 14, 2015 IP
  3. cc2365

    cc2365 Member

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    #3
    Thanks for your reply. Unfortunately, saving these images as 8-bit PNG is not a feasible solution because they are basically photos, which do not compress well in this format.

    As for changing the quality settings manually, I'm wondering:
    1. Since these images had been compressed before, setting the quality too high would be (almost) a waste of disk space. So, is there a way to check what quality setting suits my images best?
    2. Why is JPEG to PNG conversion an irreversible process, even if no modification is made to the PNG file?
     
    cc2365, Jan 19, 2015 IP
  4. TeKn1qu3z

    TeKn1qu3z Well-Known Member

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    #4
    If you're on WP, there are a few plugins that will do this for you.
     
    TeKn1qu3z, Jan 19, 2015 IP
  5. Ginni Studios

    Ginni Studios Greenhorn

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    #5
    Hi there,

    As per your requirement you need to convert a .PNG file back to JPEG, then follow these steps:

    - Open the .PNG file using Adobe Illustrator.
    - Resize the file as per your requirement.
    - Save the file in .EPS format(using ctrl + Shift + S and file type .eps)
    - Open this .EPD file in Adobe Photoshop.
    - You will have a Pop-up screen while Opening the file for file size selection.
    - Select your file size and you will see that image has been opened without pixcelation.
    - Now goto File option (in Menu Bar) and Click Save As.. Option.
    - Save the file as .JPEG format.
    - Hence you have converted the .PNG file to JPG.

    I hope this would help you.

    Thanks.
     
    Ginni Studios, Jan 21, 2015 IP