Texture

This transformation is used to create an image filled with a textured background tiled to fill the entire surface of the output image. By adjusting the texture controls, you can generate a wide range of different textures and you can also tint the texture image using a color line control. Texture images are created as top-level images since they have no input image. Textures are generated using random data that is altered using an inverse 2-dimensional Fourier transform. With a given set of parameters, variations can be generated by starting with a different set of random numbers.

Width, Height, and Resolution

These controls set the resolution and size of the output image. The current texture tile is repeated as necessary to fill the entire output image. To create an output image that can be seamlessly tiled, set the width and height to match the Tile Size (see below).

Tile Size

This control lets you choose the size of the texture cell that is repeated to fill the output image. The individual tiles join seamlessly (i.e. the pattern matches between the left and right edges and the top and bottom edges. Small tiles compute quickly but generate a very regular pattern as the small cells must be repeated many times to fill a large image. Large tiles take longer to compute but do not repeat as often.

Note: If you have CUDA enabled and select one of the larger tile sizes, you may get a warning message if your graphics card does not have enough memory. In this case, computing random tiles reverts to not using the graphics card and is much slower.

Color Line

The color line lets you specify a color sequence used to tint the texture cell. The color at the left end of the color line is applied to the parts of the texture image that are black; the color at the right end is applied to the parts of the texture image that is white. You can get some interesting effects by adding additional points to the color line and experimenting with the color line transition settings and the locations of the transition points.

Frequency

This double slider lets you specify what range of frequencies to use when synthesizing a random texture. The black slider sets the lower limit and the white slider sets the upper limit. Lower frequency values affect the coarse structure of the texture; higher values create fine structure. If the lower limit exceeds the upper limit, then the range between the two is excluded instead of being included.

Angle

This double slider lets you specify the orientation of the texture. The black slider sets the lower limit and the white slider sets the upper limit. Only frequency components whose direction falls in the range between the lower and upper limit are used to synthesize the texture. If the lower limit exceeds the upper limit, then the range between the two is excluded instead of being included.

Power

This slider lets you alter the weighting of the power spectrum with respect to frequency. Lower values generate coarser textures; higher values generate more fine structure. Setting Power to -1.0 (the default value) produces fractal textures that look similar at whatever scale you view them.

Equalize

If you check this box, the texture image is adjusted to have a constant histogram. This is done by applying a brightness curve so as make all possible brightness values more of less equally probable. If you want to use the texture as a custom halftone dither pattern, make sure this option is selected.

  Randomize

Every time you click this button a new texture is generated using the current settings but based on a new set of random numbers.

  Select 8 or 16-Bit Output

8 -- Generates an 8-bit black and white or 24-bit color texture image

16 -- Generates a 16-bit black and white or 48-bit color texture image

Tips

You can use any of Picture Window's transformations to modify a texture image once you have created it. For example, you can warp, emboss, sharpen, blur, equalize, resize, or tint it, or apply a brightness or saturation curve to it. You can also create interesting effects by creating three different textures and using the Combine Channels transformation to turn them into a composite colored texture. Finally, you can combine two or more different textures using the filter, difference, or composite transformations.

There are many ways to apply a texture to an image. The first step is to generate a texture image that has the same dimensions as the image to which you wish to apply the texture.

Method 1: Using the Brightness Transformation

This technique can be used to lighten an image where the texture image is light and darken it where the texture image is dark.

Start by creating a black and white texture image whose dimensions match those of the image you want to texture. Then open the image you want to texture in a window, click on it to select it, and select the Brightness transformation. Then click on the white square to the right of the Amount control in the Brightness dialog box and select the name of the window containing the black and white texture image. Finally, experiment with different positions of the black and white sliders in the Amount control to get different effects.

Method 2: Using the Filter Transformation

This technique can produce the same effect as sandwiching the image with a texture image to combine the two.

Start by creating a black and white or colored texture image whose dimensions match those of the image you want to texture. Then open the image you want to texture in a window, click on it to select it, and select the Filter transformation. Then click on the white square to the right of the Filter control in the Filter dialog box and select the name of the window containing the texture image. Finally, experiment with different positions of the Amount and Exposure Compensation sliders, the Complement checkbox, to get different effects.

Method 3: Using the Composite Transformation

This technique can produce the same effect as making a double exposure of the image and a texture image to combine the two.

Start by creating a black and white or colored texture image whose dimensions match those of the image you want to texture. Then open the image you want to texture in a window, click on it to select it, and select the Composite transformation. Then click on the white square to the right of the Overlay control in the Composite dialog box and select the name of the window containing the texture image. Finally, experiment with different positions of the Overlay Amount slider and the Operation options, to get different effects.

Method 4: Using a Texture as a Mask

This technique can produce a wide variety of effects.

For use as a mask, the texture image must be cropped to the same size in pixels as the image you are masking and it must 8-bit.

Start by creating a black and white or colored texture image whose dimensions match those of the image you want to texture. Then open the image you want to texture in a window, click on it to select it, and select Mask from the main menu. Then select the name of the texture image from the bottom of the Mask menu. This will place the texture over the image as a mask.

At this point, you can use this mask to selectively blur, sharpen, lighten, darken, or composite the image (see Using Masks). Or you can use the freehand painting or retouching tools to generate textured painting or retouching effects (see Using Masks with Tools).

Other Uses for Textures

There are many other ways to use textures including:

1) Creating custom screens for use with the Halftone transformation. If you use it for this purpose, make sure the Equalize box is checked.

2) Creating backgrounds for compositing (see the Composite and Layout transformations). The Texture transformation can also be used as described above to apply textures to backgrounds generated using the Gradient transformations.

3) Creating distortion maps for use with the Displace transformation

4) Creating masks for use with the Add Texture transformation