Need help: How to crop in Aperture?

PDidd117w3n7y wrote:

JPEGs lose quality every time they are opened, edited and saved.

True. If a JPEG image is opened, edited, and saved again it results in additional image degradation. It is very important to minimize the number of editing sessions between the initial and final version of a JPEG image. If you must perform editing functions in several sessions or in several different programs, you should use an image format that is not lossy (TIFF, BMP, PNG) for the intermediate editing sessions before saving the final version. Repeated saving within the same editing sessionwon't introduce additional damage. It is only when the image is closed, re-opened, edited and saved again.

Source- http://graphicssoft.about.com/od/formatsjpeg/a/jpegmythsfacts.htm

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Patrick D.
http://www.pwdphotography.com