Are these photos already in iPhoto? What version of iPhoto and system are you running?
DigiKam is a free open source software to batch convert CR2 to JPG for Windows, Linux. ARW is the raw file which is available when we click photos on the camera. We need to convert the ARW file to JPG files to see the quality picture. ARW converters are software which converts the ARW file to JPG files. It is generally a Sony Raw Image file. There are free ARW online converters available or freeware which is available for download.
If the photos are already imported into iPhoto then when you make any edits with iPhoto the resulting edit will be a jpg file.
If they are not imported into iPhoto then maybe the Sony software can convert them. Also there is a Automator workflow app that I created that will take any image file, convert it into a jpg and embed the sRGB color profile. It's called Convert to JPG and Embed sRGB profile.app and can be downloaded from Toad's Cellar. Be sure to read the waring about running it on copies as it will convert the file to jpeg and if it's not what you want you can resort back to the original raw files.
Cr2 Converter App
|Full name||Canon RAW version 2||JPEG - Joint Photographic Experts Group|
|File extension||.cr2||.jpg, .jpeg, .jpe|
|Developed by||Canon Inc.||Joint Photographic Experts Group|
|Type of format||Image File|
|Description||The Canon RAW version 2 (cr2) format is a RAW format created by Canon for storing digital images. This does not contain a ready to view picture like a JPG or PNG file, it is used to store information directly coming from the sensor. You can choose to store your pictures in RAW format which gives you the benefit of being able to do a lot of post processing on the file, if you tried to do this with JPEG, this would be difficult and would likely result in a quality loss.||JPEG is a commonly used method of lossy compression for digital images, particularly for those images produced by digital photography. The degree of compression can be adjusted, allowing a selectable tradeoff between storage size and image quality. JPEG typically achieves 10:1 compression with little perceptible loss in image quality.|
|Technical details||RAW files are the best quality to size ratio that a photograph can be stored in, primarily because each colour is recorded in either 12 or 14 bits and a lossless compression is used. The CR2 takes over from Canon's previous format - CRW and is used by the Canon 350D, 1D, G9 and 20D models.|
|File conversion||CR2 conversion||JPEG conversion|
|Associated programs||Adobe Photoshop, Adobe Photoshop Lightroom, Paint Shop Pro, Picasa, digiKam||Adobe Photoshop, Paint Shop Pro, the GIMP, ImageMagick, IrfanView, Pixel image editor, Paint.NET, Xara Photo & Graphic Designer, Apple Safari, Google Chrome, Mozilla Firefox, Internet Explorer|