Adobe has also tweaked the Color Range Select tool, adding the ability to limit the selection to "Localized Color Clusters." It sounds nice, but I couldn't get it to work well in any meaningful way; rather than limit it to contiguous colors that meet the specified criteria, as I expected, it seemed to limit the range to a user-specified-size circle around a sample point. An extension of the old Auto Align and Auto Blend capabilities combines the sharpest areas of several layers of similar images, which Adobe promotes as delivering an extended depth-of-field image. In practice, you have to be very careful or you'll end up with an odd mixture of blur and sharp that bears no resemblance to anything producible with a camera. Those image combination scripts have also been beefed up with vignette (edge darkening) and fish-eye distortion correction when creating panoramas.
Content-Aware scaling, Adobe's implementation of seam-carving technology, seems slightly more cooked than it seemed while I was beta testing the software, but it's not quite ready for prime time. For one thing, it's slow; though it's OK while you interact with it, when it comes time to apply, it can take a while. Also, if you leave it on, the program defaults, and you'll get an unholy mess. Always dial it back to at least 50 percent. The fact that you should really use a rough mask to protect important areas will slow down your work flow. Finally, it can leave behind tons of contouring artifacts.
Photoshop also has much better integration with Lightroom 2.1. You can jump seamlessly back and forth without any of the onerous saving and manual refreshing required by an earlier version of this capability. You make adjustments in LR, then open it in Photoshop, save, and jump back to Lightroom.
Of course, there's the inevitable disappointment with the stuff Adobe hasn't changed, such as the poor print layout controls and embarrassingly primitive text handling.
I'm not quite sure what conclusions to draw about CS4's performance relative to CS3. CS3 was faster across the board than CS2, but CS4 seems to have taken a small step backwards. For instance, I ran a variation of the Photoshop Action suite we use for desktop testing (for details, see the Adobe Photoshop CS3 image-processing test section on our How we test desktops page), but with the larger raw files from a 24-megapixel Sony Alpha DSLR-A900 (close to 70MB in their 8-bit form and about 140MB opened as 16-bit) and under both 32-bit and 64-bit versions of Windows Vista.
|Time (in seconds)|
|CS3, 64-bit Vista||153|
|CS4, 64-bit Vista||165|
|CS3, 32-bit Vista||185|
|CS4, 32-bit on 64-bit Vista||189|
|CS4, 32-bit Vista||217|
As you can see, CS4 ran about 7 percent slower than CS3 in the 64-bit environment and 17 percent slower in a 32-bit environment. I also created an Action that sequentially selected and rotated the entire image 20.5 degrees 3 times, which took CS4 twice as long to run on both OSes than CS3--3.3-3.7 seconds per rotation in CS4 vs. 1.7 seconds in CS3. Opening six raw files from the Adobe Camera Raw dialog takes about the same amount of time when there's sufficient memory allocated in Photoshop's preferences, but CS4 hit the virtualization border at a higher memory allocation. My guess is that the increased overhead of CS4 makes it bottleneck just a bit sooner than CS3 in the same memory environment. If that's true, Adobe has some critical optimization work to do, because that's an across-the-board problem. It's also bad news for those of us who have to run Photoshop along with other memory hogs, like Microsoft Office. (My test configuration was a 3GHz Intel Core2 Extreme X9650 system with 4GB RAM, an Nvidia GeForce GTX280 with 1GB dedicated graphics memory--and another 1GB shared--running at 1,900x1200 resolution and a 74GB WDC WD740GD hard disk. Unfortunately, our Mac testbed was misbehaving when I needed it.) Given the performance results, I can't help but think that the newly added support for 64-bit Windows was a necessity, not a luxury. Adobe was surprised by these results, and is looking into it.
There's more, of course, but nothing that screams, "I'm going to make your life easier!" Which is why I suspect users will be sighing when they plunk down the cash for the upgrade rather than eagerly anticipating all the fun times ahead. Maybe that will come with CS5, when the fruits of Adobe's technological labors have ripened and left the sanctuary of Adobe Labs for the wild.