This option is self-understanding:

Average diameter of each tile (in pixels). Slider and input box allow you to set the size of tile surface (2-1000).

That's ledge, relief of tiles. Value is width of the lit border in pixels.

When set to 1, most of tiles have the same size. With 0 value, size is determined at random and this may lead to shape variation.

Each tile has only one color. So the number of colors is reduced, compared to the original image. Here you can increase the number of colors a little.

When this option is unchecked, the image drawing can be recognized inside tiles. When checked, the colors inside tiles are averaged into a single color.

With this option tile surface looks pitted.

This option splits tiles in areas with many colors, and so allows a better color gradation and more details in these areas.

That's width of the join between tiles.

Tiles are lit with the foreground color of the toolbox, and shadow is colored with the background color. Joins have the background color. You can change these colors using the color buttons or the color pickers on the right.

By default light comes from the upper left corner (135°). You can change this direction from 0 to 360.

This option reduces the stepped aspect that may have borders.

This option controls the randomness of the filter. The Random seed box lets you manually enter a seed for the randomization algorithm used. You can also generate a random seed by pressing the New Seed button. If the same random seed is used in the same situation, the filter produces exactly the same results. A different random seed produces different results.