Using filters

Using filters

To use a filter choose the appropriate submenu command from the Filter menu. These guidelines can help you in choosing filters:

The last filter chosen appears at the top of the menu.

Filters are applied to the active visible layer.

Filters cannot be applied to Bitmap-mode or indexed-color images.

Some filters only work on RGB images.

Some filters are processed entirely in RAM.

Gaussian Blur Add Noise Dust & Scratches Median Unsharp Mask Solarize and High Pass filters can be used with 16-bit-per-channel images as well as 8-bit-per-channel images.

Previewing and applying filters

Applying filters-especially to large images-can be time-consuming Some filters let you preview the effect before applying it.

To save time when trying various filters experiment on a small representative part of your image.

To preview and apply a filter:

To apply a filter to an area of a layer select that area. To apply a filter to the entire layer, leave the image unselected.

Choose a filter from the submenus in the Filter menu If a filter name is followed by ellipses (.) a dialog box appears.

If a dialog box appears enter values or select options.

If the dialog box contains a preview window use the following methods to preview the effect:

If the dialog box contains sliders hold down Alt ( Windows) or Option (Mac OS) while dragging a slider to see a real-time preview (real-time rendering) of the effect.

Click in the image window to center a specific area of the image in the preview window.

Note: This does not work with all preview windows.

Drag in the preview window to center a specific area of the image in the window.

Use the + or - button under the preview window to zoom in or zoom out on the preview.

A flashing line beneath the preview size indicates that the preview is still being rendered.

If available select the Preview option to preview the filter effect on the entire image.

A progress indicator in the status bar ( Windows) or progress bar (Mac OS) lets you gauge the time remaining until the filter is applied.

Blending filter effects (Photoshop)

The Fade command changes the opacity and blending mode of any filter painting tool, erasing tool or color adjustment. The Fade command blending modes are a subset of those in the painting and editing tools options (excluding the Behind and Clear modes). Applying the Fade command is similar to applying the filter effect on a separate layer and then using the layer opacity and blending mode controls (See "Using adjustment layers and fill layers (Photoshop) on section 311

Note: The Fade command can also modify the effects of using the Extract command, Liquefy command and Brush Strokes filters.

To fade the effect of a filter painting tool or color adjustment:

Apply a filter painting tool or color adjustment to an image or selection.

With the affected area still selected choose Edit > Fade.

Select the Preview option to preview the effect.

Drag the slider to adjust the opacity from 0% (transparent) to 100% (See "Specifying opacity flow strength or exposure on section 243

For Mode choose a blending mode (See "Selecting a blending mode on section 241

Click OK.

Note: The Color Dodge Color Burn Lighten Darken Difference and Exclusion modes do not work on Lab images.

Loading images and textures

To produce their effects some filters load and use other images such as textures and displacement maps. These filters include the Cont Crayon Displace Glass Lighting Effects Rough Pastels, Texture Fill, Texturizer Underpainting and Custom filters.

Not all of these filters load images or textures in the same way (See "Using the Lighting

Effects filter on section 338

To load images and textures:

Choose the filter you want from the appropriate submenu.

In the filter s dialog box choose Load Texture from the Texture pop-up menu and locate and open a texture image.

All textures must be in the Photoshop format Most filters use only the grayscale infor- mation of a color file.

Defining undistorted areas

The Displace Shear and Wave filters in the Distort submenu and the Offset filter in the

Other submenu let you treat areas undefined by the filter in the following ways:

Wrap Around fills the undefined space with content from the opposite edge of the image.

Repeat Edge Pixels extends the colors of pixels along the image s edge in the direction specified Banding may result if the edge pixels are different colors.

Set to Background (Offset filter only) fills the selected area with the current background color.

Using texture and glass surface controls

The Cont Crayon Glass Rough Pastels, Texturizer and Underpainting filters have textur- izing options. These options make images appear as if they were painted onto textures such as canvas and brick or viewed through glass blocks.

To use texture and glass surface controls:

From the Filter menu choose Artistic > Rough Pastels Artistic > Underpainting Distort

> Glass Sketch > Cont Crayon or Texture > Texturizer.

For Texture choose a texture type or choose Load Texture to specify a Photoshop file.

Drag the Scaling slider to enlarge or reduce the effect on the image surface.

Drag the Relief slider (if available) to adjust the depth of the texture s surface.

Select Invert to reverse the surface s light and dark colors.

For Light Direction indicate the direction of the light source on the image.