Click on the filter menu to access the wide range of filters available for enhancing your image / layer.
In the window you’ll see a list of filters that can be applied to the active layer in the work area.
Undo 
click
anytime to reverse the last few steps.
Reset 
click anytime to
reset the image to the original state.
OK 
to accept all changes
and continue working with the image.
Cancel click anytime
to abort an operation. The filters will not take effect.
To apply a filter, first click on it in the menu.
Some filters open a preview window and provide a slider for you to set the filter value.
In the preview window you can see the filter's effect on your image.
You can repeat each filter or combine them in any way you like for special effects.
Noise – adds noise to the image. A new window opens with a thumbnail preview of the image you are working on. With the slider you can increase and decrease the noise you add. Select Monochrome to add black and white noise only. You may use this filter to make certain areas or whole images invisible or create an effect that looks like bad reception.
Emboss – makes an image relief in gray tones from your image. This filter is used to create symbols that look like embossed reliefs of your image.
Laplacian – creates a neon contour around the image. From the drop-down list you can select different variations. Pick the one you like best.
Gradient - identifies the edges of the image and adds a neon-like glow to them. >From the drop-drown list you can select different variations depending on the direction of the glow.
Posterize - unites similar tints into one color.
Mosaic - clumps pixels into square blocks.
Average - allows you to soften the image and smooths transitions between colors even more than standard blur.
Median - reduces noise in an image by blending the brightness of pixels within a selection. This filter is useful for eliminating or reducing the effect of motion on an image.
Hipass -retains edge details where sharp color transitions occur, suppresses the rest of the image and removes low-frequency detail.
Edge Enhance – edges where noticeable color changes occur are enhanced by adding a neon touch while the remaining parts of the image are darkened a little.
Sharpen – Alters color change distinction. This increases or decreases the sharpness of the layer. If you select a negative value, the image will be less sharp. If you increase the value, the image will look sharper. To a certain degree you can correct incorrectly focused images, because the blur is reduced. Sharpen images that are out of focus because of the motion of camera and object to create interesting effects. Portraits especially often gain in quality if the image is slightly smoothed first (you can also use the Noise reduction filter or the Smooth filter) and then sharpened.
Color emboss – forms a color relief of an image.
Soften – softens an image.
Blur – softens the image and smooths transitions between colors by averaging the pixels next to the hard edges of defined lines and shaded areas in an image.