The Tune blur effect (EffectsBlurTune blur) lets you apply any of four blurring effects, which are represented by thumbnails, to an image. You can adjust the blur effect and preview the image with softer or sharper focus while you are editing it. The Tune blur filter lets you improve image quality or create exciting visual effects.
The Directional smooth effect (EffectsBlurDirectional smooth) smooths the regions of gradual change in an image while preserving edge detail and texture. You can use this filter to subtly blur the edges and surfaces of images without distorting the focus.
The Feather effect (ObjectFeather) gradually increases the transparency along the edges of objects making objects blend perfectly into the background. You can specify the width of the feathered section of the object and the transparency gradient you want to use. The edge transparency can change in even increments from the beginning to the end of the feathered section (Linear edges) or in small increments at the beginning of the feathered edge, larger transparency increments in the middle, and small transparency increments at the end (Curved edges).
The Gaussian blur (EffectsBlurGaussian blur) effect produces a hazy effect, blurring the focus of an image according to Gaussian distribution, which spreads the pixel information outward using bell-shaped curves. The effect can improve the quality of bitmaps with sharp edges. Move the Radius slider to adjust the intensity of the effect. The Gaussian Blur effect supports all color modes except Paletted and Black-and-White.
The Jaggy despeckle effect (EffectsBlurJaggy despeckle) scatters colors in an image, creating a soft, blurred effect with minimal distortion. It is most effective for removing the jagged edges that can appear in line art or high-contrast images. The Jaggy despeckle effect is also a preset lens type.
The Low pass effect (EffectsBlurLow pass) removes sharp edges and detail from an image, leaving smooth gradients and low-frequency areas. The higher the settings you specify, the more image detail is erased.
The Radial blur effect (EffectsBlurRadial blur) creates a blurring effect in an image that spins around or radiates outward from a center point that you specify.
The Bokeh blur effect (EffectsBlurBokeh blur) lets you control the amount of blur applied to the outside of an editable area and adjust the transition between the area in focus and the blurred area. For more information, see Bokeh Blur effect.
The Smooth effect (EffectsBlurSmooth) mutes the differences between adjacent pixels to smooth an image without losing detail. It is especially useful for removing the dithering that is created when you convert an image from the paletted mode to the RGB mode. The Smooth effect produces a more pronounced effect than the Soften effect. The Smooth effect is also a preset lens type.
The Soften effect (EffectsBlurSoften) smooths and tones down the harsh edges in an image without losing important image detail. The difference between the Smooth and Soften effects is subtle but is often apparent when images are viewed at high resolution. The Soften effect is also a preset lens type.
The features documented in the Help are available in the full version of CorelDRAW Graphics Suite 2020. Some features may not be available in this version of the product.
Blur 
