Exported file size is smaller than Original

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Level 1

5 points

Exported file size is smaller than Original

When exporting a JPEG photo from Aperture to the desktop I noticed that the file size is smaller on the exported version. For example the original image in Aperture is 5MB but after exporting it as a JPEG Original size to the desktop it is only 3.9MB. Does anyone know why the exported version is smaller? Does Aperture re-compress images on export? Of course I understand that if I was shooting in RAW and exporting as a JPEG the resulting file would be smaller but when going from JPEG to "JPEG original size" one would pressume that the resulting file would be the same size.

Aperture 3, OS X Mountain Lion (10.8.1)

Posted on Sep 8, 2012 11:48 AM

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Answer 1

Sep 8, 2012 12:06 PM in response to Makua

Are you exporting the Version? "Export" means "make me a file according to these settings". The settings are stored in the Image Export Preset. What settings did you use? In particular, what quality setting?

Fwiw, 4 MB for a JPG is very very large.

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Answer 2

Yer_Man

Level 10

165,978 points

Sep 8, 2012 12:24 PM in response to Makua

Size refers to the Pixel dimensions of the image. So, Jpeg Original Size means it'll be the same length x breadth as the original.

Aperture does not "recompress images on export".

Think of it this way: A Jpeg is a container for your photo - like a box for shoes. When you work in Aperture it works on the image not the file. When you export it puts the image into a new box - and the size of that box will depend on the settings you choose. So more compression, smaller box. Less compression, bigger box. It's perfectly possible to export an image to a file that's larger then the original file.

To adjust the compression used on the export, Click on the Export preset drop down and note the option to Edit. Image Quality is the one to check out.

Regards

TD

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Answer 3

Makua Author

Level 1

5 points

Sep 8, 2012 12:25 PM in response to Kirby Krieger

Hi Kirby thanks for the reply. 4MB is not very large for a JPEG image, thats a pretty typical size. As I mentioned in my initial question this is when exporting the image using "export version" and then choosing "JPEG original size". If you go into the export presets I'm just leaving them at the default which is quality 10. If I increase the quality beyond 10 the resulting image is significantly larger than the original.

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Answer 4

Makua Author

Level 1

5 points

Sep 8, 2012 12:46 PM in response to Yer_Man

Hi Terrence, Thanks for the input, I think we're on the same page. What you said about the "Size" just being in relation to the dimensions completely makes sense to me. As far as the image quality settings are concerned I also get that depending on the quality I choose, the resulting image could be larger or smaller than the original image.

It would be great if there was a way to have the exported image file be equal in size to the original but I guess ultimately not neccessary.

Makes sense about the whole "box" example, basically the same concept as video and compression.

Thanks

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