Both NIK’s Viveza and Color Efex Pro offer useful additions to a digital artist’s set of detail enhancement tools. Viveza provides Structure while Color Efex Pro provides Tonal Contrast. Consider them both useful variations of the types of effects you can produce with Photoshop’s High Pass filter. So what specifically are the visual differences?
Like Photoshop’s High Pass filter, Viveza’s Structure provides a single slider but offers more options with the inclusion of negative values for soft focus effects. In contrast to High Pass, Structure enhances contours with a line that is not as pronounced as Unsharp Mask (Structure is almost incapable of producing artificially hard contouring.) and thinner than High Pass (Structure can’t be used for enhancing planar contrast like high values of High Pass.). Structure accentuates texture somewhat, which can enhance noise as well as detail, but not as much as Unsharp Mask. When Structure is applied, luminosity contrast increases, more so in shadows than in highlights where very high values stop just short of compromising shadow detail. Think of Structure as occupying the visual territory that lies between Unsharp Mask and High Pass.