App developer has launched 645 PRO, a flexible photography and processing app that provides access to the lossless output of the iPhone's camera. The company grabs the processed camera output before the phone compresses it, and saves it as a TIFF file. These files, which it slightly optimistically calls 'Developed Raw,' can then be accessed via iTunes. The app also offers a series of features such as spot metering and exposure, focus and white balance lock, as well as a series of film simulation options and aspect ratio options, but it's the uncompressed output that is, as far as we are aware, unique.

As well as uncompressed output, PRO 645 offers a good degree of control over the iPhone's camera.

Until now, the vast majority (if not all) of iPhone apps apply their image processing to images that have already been compressed as a JPEG, with the reduced processing latitude that brings. The processed images produced by most app are then subjected to a second compression step at the end of the process.

PRO 645 intercepts the camera data after it's been initially processed (demosaiced and with processing parameters such as white balance and sharpening applied), but before the phone compresses it. This file can be be saved as a TIFF (presumably 8-bit), alongside a JPEG version with whichever of the app's image manipulations you've chosen to apply. These JPEGs are also much less compressed than the iPhone's default compression, which is usually the starting point for most apps (equivalent to the maximum quality option in Photoshop, the developer claims).

Even without this access to the best-possible quality output from your iPhone, the app also offers a range of useful photographic features such as a live histogram, spot metering and the ability to independently lock exposure, focus and white balance, to give a high level of control over the images you're capturing. The only downside is that the TIFF output has to be accessed via iTunes, but it's still an interesting step forward for occasions when the camera you have with you is your iPhone.

645 PRO is available from the Apple App Store for $2.99, and we're hoping to review it in the coming weeks.