In an effort to reduce piracy Photoshop CS was the first version of the program to require product registration.

One impressive feature added into Photoshop CS was the ability for the program to automatically detect when an image of a bank note had been opened or scanned in. This feature was introduced to reduce the ease at which fake currency could be created - clever stuff.

Known as Space Monkey during development, 2005's CS2 introduced the third version of the aforementioned RAW plugin. Space Monkey added support for HDR images and saw the introduction of the red-eye tool from Photoshop Elements.

Other tools added to CS2 included the spot healing brush, smart objects, the smart sharpen feature and the vanishing point tool - perfect for editing image perspectives. CS2 also saw the ability to select multiple layers at once - handy.