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Here's my situation:

  • I've scanned several documents into JPG format.
  • The scanner scans 14x8.5 inches, but my documents are 11x8.5 so I need to crop them.
  • Every scanned doc is about 1.2 MB in size.
  • I open one in Photoshop, proceed to crop, then Save. A dialog appears asking for JPEG Options, including Quality. The default value is 10, however I can also choose 12. If I choose 10, I get an image size about the same as the original. If I choose 12, I get an image size larger than the original.

It seems incorrect to choose 12 and get a larger file size, since the final image would be smaller than the original. However, I don't want to lose quality compared to the original just because I've cropped it.

What is the best way to crop in Photoshop without losing image quality and saving in JPG?

Thanks!

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  • There is no problem here. It's working exactly as it should. Setting the quality lower increases the compression, reducing the file size. Clearly the jpegs you are editing already have some compression. Check the scanner settings - you may be able to change the compression when scanning, or you may be able to use an uncompressed format such as TIFF
    – Billy Kerr
    Dec 31, 2017 at 12:04
  • Hi Billy. I think you might have misunderstood my question. I know that lowering the compression will lower the quality and file size. My question is regarding setting the compression to 12 which in turn causes a larger file than the original.
    – zundi
    Jan 1, 2018 at 20:00
  • I have already explained why. You're opening an already compressed image, then recompressing, but with less compression, hence the bigger file size.
    – Billy Kerr
    Jan 1, 2018 at 20:11

1 Answer 1

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Crop the image in scanner utility, do not go into Photoshop for it. Scanner has a preview scan. It gives a possiblity to set the final scan area before scanning.

Scanner utility also asks the wanted format, resolution, compression level and gives a possiblity to adjust the exposure and color corrections. All settings must be decided before the final scan.

Do some tests to find the right compromise between the degradation due JPG compression and the benefits in the file size. It's your decision. Check, if PNG or compressed TIF are available. They can also save space - especially, if you have adjusted the exposure to give good white paper color. PNG and TIF use normally lossless compression methods which do not detoriate the sharpness like JPG's compression.

In case you have already done the scanning job and have a big bunch of JPGs, read this before cropping them in Photoshop:

How to crop a JPG without recompressing?

Check IrfanView. It has several lossless JPG-operations.

Web search for lossless jpg cropping gives several results. One example: https://www.thoughtco.com/jpegcrops-for-windows-version-065-beta-1700078

If you also must do color or exposure adjustments or some edits, you cannot avoid recompressing if you save as JPG. The compression setting in Photoshop is in the same way your decision as in the scanning utility.

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  • Yes, unfortunately the scans are already made and it is impractical to rescan. Thanks for the info.
    – zundi
    Jan 1, 2018 at 20:03

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