This Script is designed to save disk space by converting large Master files (usually RAW) to a smaller, compressed format (usually JPEG). A typical user may use this Script when they don't want to permanently delete non-selects (non-favorites), but also don't want to keep the large RAW files around. Converting to a full-size (same as original) high-quality JPEG can be a good compromise.

Savings may be upwards of 80%. For example, a collection of RAW files taking up 1GB of space would only take approximately 200MB as full-size high-quality JPEGs.

To run the Script, select an image or multiple images in a Project or multiple Projects, and select Convert Master File Format from the Script menu.

NOTE: If you select images from an Album or Book, the converted files will be re-imported into the correct host Project, but NOT back into any Albums or Books. Once re-imported, you can drag them into any Album you like.

The Script will ask what size you want to convert to (from Aperture's Image Export Preset preset list; the default is JPEG - Original Size), and when complete, offer a summary of how much space you've saved. If you have removed the JPEG - Original Size preset, the script will ask you to select from the list.

NOTE: If you want to make image adjustments to these photos, it's best done before you convert to JPEG. Remember that you'll be throwing away a lot of data in exchange for that hard drive space, and you'll be limiting the work you can do on the images later.

Here's what the script actually does:

1. Selected files are exported to the Desktop as the format you've chosen into a temporary folder called “Aperture Convert-Master Temp Folder”.
2. These files are re-imported back into the same project(s) you're working in. Each is also given a custom keyword that includes the chosen Export preset name, so you can find them easily later. These photos are imported as Managed, but you can Relocate Masters later if you want to move them outside of the Aperture library.
3. These exported files are automatically moved to the Finder trash once imported back into Aperture.
4. The original Master files are rated as Rejected and are hidden from view. However they are still in your Library! This is done so you can manually confirm the conversion, and compare quality if you like, before deleting the files.
5. Once satisfied with the results, delete the Rejected Master files. This will move them to the Aperture trash. Upon emptying the Aperture trash, they are moved to the Finder trash. Once deleted from the Finder trash, they are gone forever—so you have multiple chances to not make any mistakes!