I like Picture Window Pro’s “Advanced Sharpen” transformation. It would be great to find it in Photolab.
Essentially, it consists in three stages, conveniently combined under one interface.
- Noise Reduction - User-defined blurring radius and spatial frequency range where the blurring is enabled. Blurring can apply selectively to all RGB components or to the color components only, not affecting luminance.
- Speck removal - User-defined speck size in pixels, user-defined difference threshold, separately-defined dark and light specks
- Sharpening - User-defined sharpen radius, sharpen amount and halo limits for dark and light halos. Sharpening can apply selectively to all RGB components or to luminance only, thus avoidiing the accentuation of color noise.
This transformation would replace Photolab’s global Unsharp mask tool and the local Sharp/Blur controls in the equalizer.
Reference documentation for Picture Window’s Advanced Sharpen transformation:
- Each stage allows user-defined amount (0-100%) application.
- Each stage shows a histogram of spatial frequencies in the input image.
- Image preview shows before, after, and offset difference (delta).
- Spatial frequency range control defines start and end points, thus allowing for a gradual roll-off of the applicability range.
- Each stage accepts a local correction mask specifying the local area where to apply the transformation
PWP’s Advanced Sharpening tool is very well conceived. When used in combination with Photolab’s PRIME noise reduction, the result allows precise control of smoothing versus detail preservation.