Choosing a Filter menu item opens a modal dialog that lets you change settings with sliders and (for Blur) radio buttons. Each dialog has a Preview switch that’s on by default so you can view the effect immediately on the painted surface.
- Blur
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Opens a dialog that lets you specify the amount and direction of blur to apply to the layer.
- Blur The amount of blurring to apply.
- Uniform Blurs equally in all directions.
- Horizontal Blurs horizontally only.
- Vertical Blurs vertically only.
- Sharpen
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Applies a sharpening effect by adjusting the contrast between pixels at edges in the image.
- Amount The degree of sharpening applied.
- Radius The distance from each affected pixel within which neighboring pixels are affected by the sharpening.
- Threshold The contrast at edge pixels required for sharpening to occur. At higher values, less sharpening is applied.
- Find Edges
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Emphasizes edges and de-emphasizes color and midtones. The output tends to resemble a sketch with black ink on white paper.
- Threshold The contrast at edge pixels required for edge detection to occur. At higher values, fewer midtones appear.
- Contrast The contrast at edges for detection to occur. At higher values, fewer midtones appear.
- Median
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Reduces image noise without affecting sharpness.
- Radius The distance within which noise reduction occurs. Lower values tend to be more effective.
- Threshold
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Converts a color image to black-and-white.
- Threshold At lower values, pixels tend to become white, while
- Smoothness Applies a blurring or averaging effect.
- Gradient Lower values produce high-contrast output, while higher values tend toward grayscale output.
- High Pass
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Emphasizes edges near sharp color transitions and de-emphasizes the remainder of the image. This can be useful for preserving image detail before using the Threshold filter (see preceding).
- Radius The area in which the filter looks for color contrast. The higher this value, the less filtration is performed.
- Distort
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Adds “wavy” distortion to the image.
- Offset The distance pixels move along the distorting waveforms.
- Scale The relative size of the distorting waveforms.
- Iterations The number of times the distortion is applied to the image.
- Phase The relative position of the distorting waveforms.