Photoshop CS4 is a twofold release from Adobe, consisting of new tool sets and interface refinements twinned with a much-hyped performance boost.
Together with the new tabbed interface, Photoshop CS4 brings new uses for benchmark tools as well as introducing two killer new features: Content Aware Scaling and advanced Camera Raw functionality.
The first of these really is something to shout about. Content Aware Scaling - or Seam Carving, as it's also called - is a resizing process in which Photoshop can expand or shrink an image's dimensions while keeping vital elements and characters intact.
Backgrounds can be stretched in real-time, with foreground elements such as buildings and people maintaining their proportions.
Adobe has taken this technology and implemented it into Photoshop CS4 in a way that is certain to transform digital design. On its default setting, Content Aware Scaling can detect skin tones and automatically mask people within an image. Furthermore, users can now select regions of an image - a building or vehicle, for instance - and isolate these elements when scaling. The result is that while the distance between people, buildings or other masked elements may change as the image is stretched or pinched, the proportions of the masked characters remain constant.
Same tools, new uses
Photoshop CS4 introduces several new tools and navigational elements. It also adds enhanced functionality to familiar tools. The Clone Stamp tool, for instance, introduces a clipped preview in the same vein as brush previews in Vanishing Point. Users can now preview and, therefore, align far more precisely cloned regions, as well as being able to tweak brush size and opacity while editing. The Sponge Tool gets something of a makeover, too. New vibrancy controls offer an alternative to saturation levels, but do so without clipping colours. A similar tweak enhances the Dodge and Burn tools, rendering them far more usable and only editing the tone of a desired region rather than the colour.
All these new tweaks and improvements are brought under one roof by the introduction of Spring Loaded Keys. Although not a new tool as such, this is the kind of simple workflow enhancement that shaves time and effort off a project. Rather than tapping keyboard shortcuts to change tools, users can now press and hold a shortcut key to briefly switch while editing in another tool. You revert back to the original tool once the key is depressed. In practice, this means that if you are working with a brush and quickly need to mask an element of the image off, you simply hold the 'M' key, make your selection, then let go to carry on using the brush.
One of the most impressive changes in CS4 is the addition of the Adjustments panel. Instead of opening separate dialog boxes, you can now work with adjustments, masks and more from a centralised panel. This means that all of Photoshop's functionality is available while making image adjustments. What's more, Photoshop CS4 panels are now Flash-based, meaning if you can code your own SWFs in Flash, you can readily import them into Photoshop CS4.
Accelerated art
Photoshop CS4 can now make use of 64-bit processing on Windows and harness the GPU power of OpenGL 2.0 and Shader Model 3.0, significantly enhancing Photoshop CS4 Extended's 3D editing capabilities.
Photoshop CS4 Extended also supports direct painting, editing and rendering of 3D models and formats including OBJ, Collada and U3D formats. On the Mac platform, 16-bit printing is fully supported, as is the ability to preview out-of-gamut colours.
The added RAM performance of a 64-bit environment makes editing large, multi-layered PSDs easy. Improved performance is none more obvious than while utilising Photoshop CS4's new Rotate View tool (like that in Corel Painter), which enables you to rotate your canvas as you would a sketchbook.
The bottom line
So is this a killer upgrade from Adobe or a mere performance tweak? In essence, it's a lot of both. There are very few digital designers and artists who will be working on images large enough to warrant 64-bit processing - we're talking 300MB-plus files here - but the GPU acceleration and new navigational options and editing tools do indeed make this a seriously impressive release.
Photoshop CS4 is available in two versions - the 'standard' version costing £569 and the Extended release which will set you back £887. Look out for Photoshop CS4 tutorials - exploring some of the best new features - coming soon in Computer Arts.
New features at a glance
Live, non-destructive edits via the Adjustments panel
Re-editable masks
Content Aware Scaling tool
Fluid canvas rotation
GPU accelerated performance
64-bit support (Vista only)
Advanced 3D editing and painting
Ultra-smooth pan and zoom
Extended depth of field
Enhanced motion support
Tabbed interface
Refined Camera RAW support
Auto-blend and Auto-align tools
