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ballstothis
Known Participant
September 28, 2023
Answered

Filesize witch-craft! Please explain

  • September 28, 2023
  • 2 replies
  • 846 views

Can someone please explain what kind of black-magic witchcraft is going on here?

I received this huge PSB layered file, which I trimmed down, flattended and saved as /saved a copy.

I've tried JPG & PNG, whatever I exported flattened file comes in at 102 MB.

 

I've checked the file is 8bit, RGB. I've reduced the size to 432px X 648.

 

Also, the finder details say 24bit even though it's 8bit in working form.

I just can't explain it. Is the file corrupt? 

    This topic has been closed for replies.
    Correct answer D Fosse

    This is probably DocumentAncestors metadata. This is a complete record of copy/paste/place operations, and it can grow to enormous sizes for templates and so on that have been reused ad infinitum. As the purpose dictates, this will travel along in a paste.

     

    Export and Save For Web will strip out all this metadata.

    2 replies

    Conrad_C
    Community Expert
    Conrad_CCommunity Expert
    Community Expert
    September 28, 2023

    The problem seems to be specific to that one image, because the problem doesn’t happen when you start a document from scratch. Now I’m thinking it shows symptoms of a bug previously discussed here, where certain metadata becomes absurdly large. I’m not intimately familiar with it, but if you follow these links and see if anyone’s suggestions help, that might get you somewhere.

     

    Inflated JPG File Size - Photoshop Document:Ancestors Metadata

    https://www.google.com/search?q=photoshop+file+size+ancestors+bug

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    ballstothisAuthor
    Known Participant
    September 28, 2023

    We solved it Conrad. Thanks again for your efforts!

    Conrad_C
    Community Expert
    Conrad_CCommunity Expert
    Community Expert
    September 28, 2023

    The 24-bit part is probably easily explained:

    Photoshop says it’s 8 bits/channel.

    File Properties says it’s 24 bits.

    Those are the same thing: 8 bits per channel * 3 RGB channels = 24 bits total.

     

    The file size is more of a mystery. In my tests, a 432 x 648 image should be 200-400KB in JPEG or PNG.

     

    In Photoshop:

    When you choose Image > Image Size, at the top of the Image Size dialog box what does it say for Image Size (in K) and dimensions?

    When you choose File > Save for Web (Legacy), what does the file size preview say for JPG and PNG?

     

    If you select the same file in Adobe Bridge, or another image editor, what does it say the file size is?

     

    What media is the file stored on, a typical computer SSD or hard drive, removable media, network storage…?

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    ballstothisAuthor
    Known Participant
    September 28, 2023

    Hey Conrad,

     

    Thanks for your input. I've been using Photoshop professionally for years but this is really weird. FYI, I've just updated photoshop to the latest version but i'm still having the same issues. 

    Something really screwy is up with the image itself. I've never seen this before.

     

    I create a blank image 432px x 648px 150ppi 8bit. - Saved as JPG comes out at 18.7KB

    I then paste my 'problem' image (with no filters or anything) at the exact same proportions, ontop of this file. Checked that the dimensions are identical (no oversized layer), flattened and save JPG. Comes out at 102MB?

    B
    ballstothisAuthor
    Known Participant
    September 28, 2023

    Here's a view of the files in Bridge. Showing the various sizes and scales. Very strange.

    This only happens when I paste or use the flattend image I was supplied.

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