A CR2 file is an image taken by a Canon digital camera. Based on the more common TIFF image extension, CR2 files do not compress the image data, leaving the user with high-resolution images with large file sizes. These raw images give you more flexibility in making photo adjustments. You can compress the CR2 files to the more common JPEG format on your Mac. Though Mac's standard Preview application is not CR2-compatible, another program Apple includes with all its computers is.
Right-click the CR2 file you wish to convert.
Select "Open With."
Select "iPhoto" from the list that pops up.
Select "Export" from the "File" menu.
Click the "File Export" tab.
Select "JPEG" next to "Kind."
Click "Export." Select where you want to save the new JPEG file, then click "OK."