Smart SharpenThe new Smart Sharpen filter is a fascinating piece of work. Unfortunately, it shares with Reduce Noise a significant lack of speed, both in execution and, worse, in updating the proxy image when you change settings. For Web-resolution images, it's just about the greatest thing since sliced toast, but for high-resolution images its usefulness is much more debatable.We suspect that somewhere inside Smart Sharpen lies the algorithm that lets the CSI team read that suspect's driver's license from a convenience store security camera frame grabthe catch is that this filter would have to run for about six months to produce the result.If you need to make low-resolution images look good on screen, Smart Sharpen is great. If the idea of making sharpening masks fills you with terror, Smart Sharpen does a fairly good job of differentiating edges from non-edges. It's quite useful for capture sharpening, though on the whole we still prefer our tried-and-true techniques. On the other hand, it's a very slow and difficult way to do output sharpening. Smart Sharpen Remove ModesSmart Sharpen is really three sharpening filters in one. You select which one you want to use by choosing an option from the Remove menu (see Figure 9-24). Figure 9-24. The Smart Sharpen filter[View full size image] Gaussian BlurThe Gaussian Blur mode isironicallythe Unsharp Mask with a new user interface. If you turn on the More Accurate option (when would you want "less accurate"?) the result is a good deal gentler than Unsharp Mask at the same Amount and Radius, but it's basically the same type of sharpening. We don't see any compelling reasons to use it. Lens BlurIn Lens Blur mode, Smart Sharpen is a whole different animal than Unsharp Mask. Lens Blur uses much more sophisticated algorithms than Unsharp Mask (or Smart Sharpen in Gaussian Blur mode) to detect edges and detail, and hence typically produces better sharpening with less-obvious sharpening halos. Motion BlurIn Motion Blur mode, Smart Sharpen tries to undo the effects of blurring caused by either camera or subject movement. If the movement is truly unidirectional, it does a surprisingly good job, but camera shake rarely happens in all directions, and subject movement is often quite complex, so don't expect blurred subjects to be rendered razor-sharp by the filter. We typically apply Smart Sharpen's Motion Blur on small areas of images rather than globallyfew images benefit from global application. Advanced ModeWhen you choose Advanced mode by clicking the Advanced radio button, two additional tabs, labeled Shadow and Highlight, become available. They offer controls very similar to those offered by the Shadow/Highlight command found in the Adjust submenu (under the Image menu)see "Shadow/Highlight" in Chapter 6, Image Adjustment Fundamentals.Each tab provides three sliders for Fade Amount, Tonal Width, and Radius. They let you reduce the strength of the shadow and highlight sharpening contours, allowing stronger sharpening of the midtones.Fade Amount controls the strength of the fade from 0 to 100 percent.Tonal Width controls how far up from the shadows or down from the highlights the adjustment extends into the tonal range.Radius controls the size of the neighborhood used to decide whether a pixel is in the shadows or the highlights. A useful rule of thumb seems to be to set the Radius in the Shadow and Highlight tabs to double the Radius setting in the main panel. Thus far, our use of Smart Sharpen is confined to the Lens Blur and Motion Blur modes, and we always use the Advanced setting with the More Accurate option turned on. Smart Sharpen in ActionAs with the Unsharp Mask filter, the key parameter is Radius. While you can obtain some interesting contrast effects with very high Radius settings (just as you can with Unsharp Mask), you typically need to match the Radius to the image content to obtain good sharpening. But as you'll see, you need very different Radius settings for the Lens Blur and Motion Blur modes.We start out by setting the Amount all the way to 500 percent, in Basic mode, while we find the correct Radius setting (see Figure 9-25). Figure 9-25. Setting the Radius[View full size image] Figure 9-26. Setting the Amount and Advanced settings[View full size image] Figure 9-27. Small-Radius sharpening[View full size image] Figure 9-28. Removing Motion Blur[View full size image] Figure 9-29. Removing Motion Blur on details[View full size image] |