# GUM v.1.0.0

# 21

# Artistic filters

Filters that create instant artistic effects such as oil paintings or mosaic floors. In general they are ready-to-run filter that demand little attention from the user.

## Apply Canvas

This filter applies a canvas structure to your image or selection. This will obviously making it look more like a painting. You can specify four different canvas directions, as well as how "rough" the fabric should be. The Depth slide bar controls the canvas structure. A high value will get you a very rough and prominent canvas texture while a low value results in a softer, smoother canvas.

## Cubism

Transforms your image to cubist art. If you check Use background color, the background color will appear between your tiles, otherwise this area will be black. Tile size determines how "cubist" you want your image to be; higher values result in a more abstract image. The saturation value decides how colorful the image will be.

#### Tip

To achieve interesting effects, try applying cubism to several layers with different modes over the original image.

## Mosaic

With this plug-in you can imitate everything from a stained glass window to a ceramic mosaic floor. This plug-in has many parameters that lets you control the final result; Size and height of the tiles, the spacing between them, and the neatness which controls the appearance of the stones.

If you use a hexagon shape, the stones will be hexagonal with a high neatness value. If you lower the neatness value, the hexagonal structure will fade, and the stones will look more like the natural stones you find in the open.

Light direction controls how the daylight will appear to shine on the mosaic edges. Color variation adjusts how much the color is allowed to fluctuate. With a low value, the original color from the image will be preserved.

Tiling primitives is what kind of mosaic tiles (stone structure) you want as a base for your mosaic. If you set a low neatness value and a high color variation value, you will get a very abstract mosaic. Antaliasing produces smooth edges.

Color Averaging creates a true mosaic. If this option is unchecked, the original picture will only get a mosaic texture. Pitted Surfaces will get you a surface that looks old and used. FG/BG controls edge color. If unchecked, it will use the foreground from the toolbox, BG will use the background color.

### Tip

You can create very interesting surfaces with Mosaic. You can for example take a stone pattern and combine it with Mosaic to get something that looks like an old stone floor, or with another combination, perhaps a cracked glass/windshield etc...

## Oilify

As you might guess, it makes your image look like an oil painting. Mask size sets the outcome. A high value gives the image less detail (as if you had used a larger brush).

#### Tip

This tool is nice to use with several layers. You can also use it to help you select intricate objects by running this filter on a duplicate layer; a simplified shape is much easier to select.

## Van Gogh (LIC)

Van Gogh can be used as a blur tool or as a texture maker. In short, this plug-in has more in common with the texture or displace filters than the artistic ones, even though you can achieve quite artistic results with it.

- To create a blur, check Convolve with source image before applying the filter.
- To create a texture, check Convolve with white noise.

### Map image

Whether you want to make a pattern or a blur effect, you must first create a map image. Effect Channel determines which HSV channel should be used (brightness is generally best). Effect Operator controls the direction of the pattern or blur. Derivative sets the direction to the opposite of Gradient. If your map image has a certain direction, the Effect Operators work much the same way as Flip in the toolbo
x.

### Blur

Blur: The advantage of this filter is that the map image determines the direction of the blur. This means that you can adapt a gradient to create variation, movement and a sense of direction in blurring. A radial gradient creates a circular blur movement, a horizontal linear gradient (meaning when you drag left to right) puts an emphasis on vertical lines in the image because it blurs horizontal lines, and vice versa.

A solid color object in the map image doesn't create a blur effect (except for the antialiased edges) - you must use some sort of gradient in the areas you wish to blur. I recommend that you use the default settings with the exception of Filter Length which controls the strength or depth of the blur, and in some measure also Integration Steps. Use a black/white gradient map and nothing else. (You can of course use all sorts of image maps, but in most cases that doesn't accomplish more than a general blur over the entire image).

### Texture

Texture: You can create many interesting patterns and textures with Van Gogh. This filter is especially good for making patterns that look like woven or knitted textiles or fabrics. Use a target image with a solid color or a color pattern you think would fit your texture. Use a grayscale gradient, or blurred mask as map image, set Integration Steps a bit higher than default, and experiment with the other settings to get the sort of texture you wan
t.

When you use this filter as a texture maker, the settings are more important than when you use it for blurring.

- Max/Min Value controls contrast. If the Max/Min range is large, contrast is low. The contrast increases when you shrink the interval. Does not affect Blur
- Integration Steps control how much the map gradient is allowed to influence the shape of the pattern (large integration = large influence). Don't set this parameter to low for Blur, Default is fine
- Noise Magnitude controls the amount and size of random noise (that breaks up the regularity of the pattern). Low values produce finely grained surfaces (sand), and high values produce coarser materials (large bumps and holes). Does not affect Blur
- Filter Length controls depth just like in the emboss filter. Low filter lenght=smooth surface, High filter length=rough surface. Controls the strength of the Blur (compare the two images to the right)

####
Creating a nice burlap cloth texture:

Run the filter twice on a white image. Check White noise (for pattern), select a quite small interval for Max/Min, and put the other slide bars somewhere in the middle (higher for creating a coarser fabric). Use a diagonal linear gradient as map, and set Gradient the first time and Derivative the second time, this inverts the direction of the pattern. Paste the second result image to a new layer in the first one, and set Lighten only mode (or other suitable mode).

## Warp

Warp (or syrup in sour cream) is a nice little filter. I'm not kidding about the sour cream, it's actually a lot like the patterns you made as a child with a spoon in a bowl of thick cream and juicy berries or syrup. To make this work properly, you'll need a Displacement map. To create syrup curls, you should use the Solid Noise filter in the Filters/Render menu for a displacement map (don't use Noise filters from the Filters/Noise menu, that's another kind of noise).

The more detail and small turbulences you have in the map image, the more, frizzier and smaller curls you'll get. Make sure that the map image is the same size as the image you want to work the filter on. If you only want to warp a small part of the image, you can erase or cut part of the map image, and only leave an area which is about the same size and shape as the area you wish to warp in the target image. When you wish to specify a more exact position, size and shape of the warpable area, use a Magnitude Map instead.

### Main Options

- Step Size controls the amount, or strength of the filter. The value you set here affects the image for every iteration, or warp step you make.
- Iterations sets the number of times the filter should repeat the effect.
- On Edges refer to the way the plug-in deals with background color at the distorted edges (see Displace Filter chapter 32)

### Secondary Options

- Dither Size causes pixels to displace randomly, thus decomposing the image. A moderate dither size just makes the warp curls look more grainy. Larger values scale from fuzzy particle clouds to total disintegration of the image.
- Rotation Angle determines what the "curls" will look like. 90 degree rotation, which is the default setting, makes them look like small whirlpools. A 0 degree rotation looks more like the kind of solid distortion you'd see through a bathroom window. Every other angle are combinations of these two, more or less so depending on how close they are.
- Substeps increases calculation time for each flow step. There is a slight improvement in warping, but it is much slower.
- Magnitude Map is a more subtle way of controlling what parts of the image should be warped and how much. The magnitude map should be a grayscale image, where areas you do not wish to affect are black. Warp magnitude is determined by a brightness scale. White represents 100% (or normal warp), black stands for no warp at all, and the different shades of gray weaken the warp effec
  t.

### Other Options

- Besides the Warp displacement map, you can add a Gradient displacement map. This map will not displace in the curly warps you have seen before. Here displacement depends on the direction of the gradual transition which makes the distortion straight and angular. The Gradient Scale sets the amount of influence the gradient map should have.
- You can also displace along a fixed direction by using a Vector map. This option lets you displace a chosen map one step per iteration in a certain direction. Vector Magnitude determines by how many pixels the image should move for each iteration, and the direction is specified in the Angle swatch. A Vector map is something in between a Displace and a Magnitude map. It protects black areas and the rest of the image moves along the vector direction. The smoothness of the stretch is determined by the number of pixels specified, a low value here gives a smooth disfigurement of the image

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Generated by fmtoweb (v. 2.9c) written by Peter G. Martin <peterm@zeta.org.au> Last modified: 19 May 1998