Want to know more about filters? Then keep reading. The rest of the chapter walks you through what each filter is for and gives recommendations on different uses. We'll look at the filters in the order they are presented in the menu. This is for ease of reference when you want to come back and look things up.
Next to each description you'll see the filter in action, processing an image. I've rendered two different outcomes with each filter. The left image is a more "traditional" use of the filter. The right image uses more extreme settings or blending modes to achieve a different look. You'll find the source images in the Chapter 14 folder. Feel free to open the image and try the filters out.
The Artistic Filters are direct descendants of the Gallery Effects filter package. These effects were originally sold as a stand-alone product, but were bundled with Photoshop when Adobe bought Aldus (original creator of the page layout program PageMaker). These filters are "old" and their looks are often overused.
Note: Dialog Boxes
If a filter uses dialog boxes, the filter's name is followed by ellipsis (...). This means that a dialog window will launch and allow you to customize the effect.
The Colored Pencil filter produces a very predictable result. The key to achieving variety depends on the color loaded as your background color, as this becomes the "paper" that shows through. Shorter stroke width combined with a higher pressure setting generally produces the best results. Using white as the background produces a natural look. To further enhance the filter, choose Fade immediately after running it and set the filter to Hard Light mode.
The Cutout effect produces a very pleasing look where the image is simplified to the point that it looks like pieces of colored paper that have been roughly cut out and glued together to form an image. A higher setting of edge simplicity produces a better look.
The Dry Brush produces a very traditional paint effect, somewhere between oil and watercolor. The strokes are very defined, and it is possible to introduce a visible texture.
At low values, Film Grain can be used to introduce a fairly realistic grain. This can be employed when mixing computer-generated graphics with material shot on film. At high values, the effect produces a gritty posterization effect. This can be useful for stylizing items for an aggressive, youthful look.
Fresco is a traditional art technique in which earth colors are dissolved in water, then pressed into fresh plaster. What you get with this filter is a darker image with small swirls. The look can be useful for simple photos, but gets too "mushy" on photos of people or small objects.
The Neon Glow filter uses three colors to produce its results: the foreground, background, and one additional color specified within the filter's dialog box. This effect can be used to add a variety of glows to an image, as well as colorizing and softening.
Paint Daubs is the most versatile of Photoshop's Artistic Filters. It comes with six paint styles and 50 brush sizes, which give you a lot of variety. Brush types include simple, light rough, dark rough, wide sharp, wide blurry, and sparkle. If you need a painterly look, choose Paint Daubs.
A palette knife is a thin, flexible blade used by artists to mix paints. This filter reduces detail in an image, giving the effect of a thinly painted canvas. This gives the appearance of the canvas's texture showing through.
The Plastic Wrap filter is better suited for producing text effects, although most of its results can be generated by Layer Styles. When using it on an image, it simulates the effect of coating the object in shiny plastic. To gain finer control, fade this filter, and then adjust blending and opacity controls.
The Poster Edges filter posterizes an image (removes the number of color steps or gradients). It also finds the edges of the image and draws black lines throughout the image. This filter produces a lot of detail in the resulting image.
Rough Pastels is a pleasant effect that simulates the image being drawn with strokes of colored pastel chalk on a textured background. The chalk appears thick in light areas, and the texture shows through more in darker areas. This filter is very flexible as it lets you load your own textures.
The Smudge Stick filter softens an image using short diagonal strokes. These strokes smudge or smear the dark areas of an image. The light areas lose some detail and become brighter.
The Sponge filter simulates the traditional art technique of painting with a sponge. Images are highly textured with areas of contrasting color. The resulting images will be clearer if you fade the filter.
The Underpainting filter is very similar to Rough Pastels. Its texture controls are where its true power lies. The filter gives the appearance of a softly painted image over a textured background.
The Watercolor filter paints the image in a watercolor style. Details are simplified because of the larger brush size. Saturated areas will become darker as well.
You'll often need to soften an image, and Photoshop offers plenty of choices. Some are more useful than others, so be sure to understand your options. Beyond obvious uses, Motion Blur and Radial Blur can be used as design effects, especially when faded or blended. If applying a Blur filter to a layer with transparency, make sure the Preserve Transparency option in the Layers palette is turned off; otherwise, the image will defocus but have crisp edges.
The Average filter is a newer filter and was a welcome addition to Photoshop CS. This filter analyzes the color of selected pixels in a selection to determine an average value, then fills with that color. While that may sound pretty tame, it's a great way to kill off noise in a sky or grain in your shadows. This filter works well with the Select Color Range command.
The pixel values of the image were averaged to a single value.
Blur and Blur More
If ever two filters could be replaced (or simply forgotten), these are they. Blur slightly (practically unnoticeably) softens an image. Blur More will do the same about three times more. Both require repeated applications and are inferior to the Gaussian Blur filter.
The Box Blur filter softens an image based on the average color value of neighboring pixels. You can use this filter to create special effects. Try adjusting the size of the area used to calculate the average value for a given pixel. By using a larger radius, you'll achieve greater blurring.
Gaussian Blur is the blur filter you will use most often. The term Gaussian is frequently used to signify normal distribution. This filter is appropriately named as it generates a bell-shaped curve when Photoshop applies a weighted average to the pixels. This filter is very fast and has great controls. It is typically used to defocus an area or an entire image. It can be run on drop shadows or glows to add natural softness. Blurring an image, then fading it opens up a whole new world of stylized color correction.
The Lens Blur filter adds a very needed depth-of-field blur to Photoshop. Before running this filter, create an alpha channel to serve as the depth map. Be sure to check out Chapter 11, "Repairing and Improving Photos," for more information.
The Motion Blur filter produces a very photorealistic simulation of a delayed exposure. This can be used to simulate motion or to add streaks of light from an image. This filter blurs an equal amount in two directions, which can be set from an angle dial. The intensity settings range from 1 to 999 pixels. This filter also produces very nice results when it is faded.
The Radial Blur filter is plagued by a poor interface, but can be used to produce nice effects. It is designed to simulate the blur of a zooming or rotating camera. Spin blurs along concentric circles; Zoom blurs along radial lines. Both allow a variable between 1 and 100. Move the center point in the filter dialog box to aim the blur's center.
The new Shape Blur filter was added to Photoshop CS2 and allows you to use a specified kernel to create the blur. Choose the kernel from a list of custom shape presets, then adjust the radius slider to change its size. Additionally, you can experiment by loading different shape libraries by clicking the triangular submenu.
The Smart Blur filter can be thought of as a "selective" blur. The filter allows you to set a tolerance setting (threshold) for finding dissimilar pixels and specify a radius so it knows how far to search. These pixels can then be blurred a specified amount and quality setting. The filter can blur the entire image (normal mode) or focus on the edges (Edge Only and Overlay). These last two modes often produce unexpected results.
The new Surface Blur filter allows you to blur an image while preserving edges. It can be useful for removing noise or graininess. Adjust the Radius option to specify the size of the area sampled for the blur. The Threshold option controls how much the tonal values of neighboring pixels must differ from the center pixel value. Pixels with sufficiently different tonal value (less than the Threshold value) are not blurred.
Brush Stroke Filters
The Brush Stroke filters should have been named Artistic Filters Part II. They are also leftovers from the Gallery Effects package and are meant to give a painterly or fine arts look. These filters use brush-and-ink stroke effects to produce a variety of looks. They can also be used to add grain and texture to an image.
Use the Accented Edges filter to accentuate the edges of an image. This filter generates a traced edges look. When the edge brightness is set to a low value, the accents resemble black ink. When set to a high value, the accents look like white chalk. This look is very pleasing and has a nice softening effect.
The Angled Strokes filter "repaints" an image using diagonal strokes. You can choose the balance between right and left strokes. The lighter areas of the image are painted in strokes going down to the right, whereas the darker areas are painted going down to the left.
The Crosshatch technique shades an image with two or more sets of parallel lines. This filter preserves the original details of an image, but adds texture and roughens the edges. The technique resembles the use of a pencil hatching.
The Dark Strokes filter is a bit unusual in that it appears to "burn" the image. The dark areas of an image are moved closer to black with short, tight strokes. The lighter areas of the image are brushed with long, white strokes. This filter can be used as a "grunge" filter, especially when combined with blend modes and fading.
The Ink Outlines filter redraws an image with fine narrow lines. These lines go over the original details, simulating a pen-and-ink style.
The Spatter filter produces rough edges while simulating the effect of a spatter airbrush. When using this effect, be sure to simplify it.
The Sprayed Strokes filter is very similar to Spatter. It produces rough strokes of the dominant colors in the image.
The Sumi-e filter tries to simulate a popular Japanese painting style. The image "looks" like it was painted with a wet brush full of black ink on rice paper. The result is a soft blurry image with rich blacks. This filter closely resembles Dark Strokes.
The Distort filters allow you to bend, push, squish, and completely reshape your image. These tools can simulate 3D space and can be quite useful when building backgrounds. Many of these filters are memory intensive, so if your computer is slow, be patient.
The Diffuse Glow filter acts very much like a diffusion filter applied to a camera lens. It is possible to get a very subtle or dramatic effect. The glow color is driven by your loaded background color; a white, or off-white looks best. If you get strange results, choose a different color. The image will be rendered with film grain and white noise, with the glow fading from the center of the selection.
In the two examples of the Displace filter, I've used a grayscale file (the left image) to displace (distort) the source photo. Can this filter do a lot? Yes. But it requires you to build your own displacement maps (grayscale files) for it to work.
So, was it was worth it? Maybe not, as the filter lacks a Preview box and takes a lot of steps. Some users swear by the Displace filter (others just swear at it).
The Glass filter is a versatile filter that allows you to distort an image so it appears as if it is being viewed through different types of glass. There are some presets to choose from, or you can create your own glass surface as a Photoshop file and apply it. With controls for scaling, distortion, and smoothness settings, quite a bit is possible. This filter can also be used for creating pleasant ripple or haze effects. To create your own map, follow the instructions for the Displace filter.
The Lens Correction filter is designed to fix common lens flaws such as barrel and pincushion distortion. It can also remove vignetting and chromatic aberration.
You can store settings that match your lens. Additionally, the filter can be used to fix perspective problems caused by vertical or horizontal camera tilt.
The Ocean Ripple filter should have been called Glass Lite. It does a very similar effect, adding randomly spaced ripples to the image's surface. The intent of the effect is to make the image appear as if it were underwater. The effect is not very convincing, but can be useful as another glass filter.
Think of the Pinch filter more as a "pucker & bloat" filter. It is possible to take a selection and squeeze it in with a positive value (up to 100%). The opposite effect of pushing the image out can be achieved with a negative value (up to -100%). Applying this filter to only a portion of the image adds a nice "pop-up" effect.
Let me suggest you give up on understanding the Polar Coordinates filter. This filter is designed to change an image or selection from its rectangular to polar coordinates, and vice versa, according to a selected option. Technically, it is designed to counteract shooting with curved lenses or mirrors; however, some cool effects can be generated.
When combined with other filters, the Polar Coordinates filter provides a nice way to "scramble" an image. This can be quite useful in creating backgrounds or patterns. This way the source image is unrecognizable, but the colors come through nicely.
The Ripple filter adds a pattern similar to ripples on the surface of water. You have three sizes of ripples to choose from, as well as control of quantity of ripples. For greater control, use the Wave filter instead.
The Shear filter uses a curve to distort the image. To form a curve, simply drag the line in the filter control box. You can add additional points by clicking on the line and pulling. Click Default to reset the curve to a straight line. You can also specify whether edge pixels wrap or repeat.
The Spherize effect is very similar to the Pinch filter. It simulates a 3D effect by wrapping a selection around a spherical shape. It can distort an image by making it appear to wrap around the outside or inside of a sphere.
The Twirl effect rotates a selection more sharply in the center than at the edges. If you fade this filter immediately after running it, you can get a nice effect. The only control of this filter is specifying an angle that produces the twirl pattern. To produce a more realistic effect, run this filter several times with a lower twirl amount.
The Wave filter is very powerful. You have tremendous control over the shape of waves, quantity, amplitude, and wavelength. The Randomize option is also helpful. This filter produces very realistic wave distortions.
Even better, though, this filter is very useful in generating background patterns. Just push the number of generators way up, and play with the other settings.
The ZigZag filter produces a different kind of ripple, one that radiates from a center point, much like a drop hitting a flat surface of water. You have three types of ridges to choose from, as well as a quantity slider. This effect also produces a nice effect on text.
The Noise filters are used to remove or add noise. This can be helpful when blending a selection into the surrounding area. Noise filters can create textures or grain. They can also remove problems that cause moiré effect.
The Add Noise filter introduces random noise to the image. It can be grayscale (monochromatic) or multicolored. The Add Noise filter is also useful for reducing banding in gradients. If you have done a lot of retouching, add noise to match previous grain. You have two distribution methods for adding noise. Uniform distributes noise using random numbers for a subtle effect; Gaussian distributes noise for a speckled effect.
The Despeckle filter combines edge detection with blurring. It is useful for finding speckles in an image, and softening them. This produces the effect of removing or limiting noise in an image. There are no sliders to adjust, just keep repeating the filter [Cmd+F (Ctrl+F)] until the desired result is achieved.
Dust & Scratches
The Dust & Scratches filter provides a more powerful way to remove noise from an image. Dissimilar pixels are modified to achieve a balance between sharpening and hiding defects. You'll want to try different settings on your image, as a wide variety of results are possible. It may be helpful to run the filter on only part of your image at a time.
To use the filter, follow these steps:
The Median filter is most useful as a way to eliminate moiré patterns. If your scanner does not have a descreen option, run this filter on your scans. This filter is very sensitive, so only use a low value for image correction. High values can be used to get an interesting softening effect. The filter examines the radius of a pixel selection for pixels of similar brightness. Any nonmatching pixels are discarded and replaced with the median brightness value of the searched pixels.
The Reduce Noise filter is a new filter to Photoshop CS2. It can be used to reduce noise, as well as smooth out JPEG artifacts. To use the filter
The Pixelate filters can be used to produce a variety of pixel types. They work by clumping similar color values in cells together into new cells. You can use these to process an image into a different look, often slightly stylized. These filters also work well at high pixel sizes for creating background layers.
The Color Halftone filter simulates the effect of getting too close to the Sunday comics. An enlarged halftone screen is very visible on each channel. The image is divided into rectangles, and each rectangle then becomes a circle (sized proportionally to the brightness of the rectangle).
Pixels are clumped into polygons with a solid color. The Crystallize filter can generate a stained glass look at a small cell size, or simplify a complex image into a bed of color for use in composite building.
The Facet filter produces a very subtle change to pixels. Don't be confused when you run it; no dialog box appears. It may take several repetitions to notice the effect, so keep pressing Cmd+F (Ctrl+F). Similarly colored pixels are clumped together into blocks of like-colored pixels. This provides for a nice painterly effect.
Four copies of the image are created, averaged, and then offset from each other. The Fragment filter produces a blur effect that may make you feel dizzy.
Mezzotints are a traditional Italian process of engraving copper or steel plates by scraping and burnishing. This produces areas of extreme light and darks. These plates were often used to make prints that would contain random pattern of black-and-white areas or of fully saturated colors. Stick with the longer dot patterns from the Type menu in the dialog box; you may also need to soften the resulting image. This is a nice effect for stylizing images.
The Mosaic filter clumps pixels into larger pixels (square blocks) to form images. These new pixels are the averaging of the original colors in the selection. Think of this as your classic video game filter.
The Pointillize filter simulates a pointillist painting. The image is broken up into randomly placed dots. The background color loaded acts as the "paper" color. If you set the cell size extremely large, you can generate acceptable texture plates.
The Render filters are a mixed bag. Some, like Clouds and Lighting Effects, produce beautiful photo-realistic results. Others, like 3D Transform, are clunky and slow. Spend a little extra time on these, as they can be quite handy.
The 3D Transform filter maps your image to crudely created cubes, spheres, and cylinders. These shapes can then be rotated or distorted. This filter is slow and appears to be an idea that didn't make the complete leap from the old application, Adobe Dimensions. Starting with Photoshop CS, you must manually install 3D Transform. You'll find it on your Adobe Photoshop CD in the Goodies Folder.
The Clouds filter is incredibly useful. It generates a soft cloud pattern from random values between the foreground and the background colors. Every time you run this filter, you get new results, so if you don't like the clouds generated, just press Cmd+F (Ctrl+F) to run the filter again. To create starker cloud patterns, hold down the Option key (Alt key) when you run the filter.
For retouching work, it can create nice clouds that you add into blown-out skies. Simply load your foreground and background as off-white for the clouds and a blue for the sky. This filter is also the starting point for many background textures.
The Difference Clouds filter is very similar to the Clouds filter, but it blends the new cloud data with the existing data using a difference-blending mode. Running the filter for the first time will invert portions of the image. Applying the filter several times creates a marble-like effect. This filter uses the foreground and background colors.
Photoshop CS adds a new texture generator called Fibers to simulate natural fibers. Your foreground and background swatch affect the fibers, but you can always change the color afterward with an image adjustment. You can experiment by clicking the Randomize button.
The Lens Flare filter creates what many see as mistakes. A lens flare is the refraction caused by shining a bright light into the camera lens. You can specify where the flare occurs by clicking the image thumbnail or by moving the crosshair. Many designers use this as an element or for down-and-dirty lighting effects. Photoshop CS adds a new flare type: Move Prime.
Lighting Effects is a diverse filter that lets you simulate 3D lights being added to your shot. You have a lot of choices with this filter, so start with the presets. You can pick from 17 light styles, three light types, and four sets of light properties. All of these can be tweaked and repositioned.
The Texture Fill filter is fairly obsolete. It lacks controls over the size of the texture as well as blending options. A much better option is to create a pattern fill layer and modify its more flexible options to taste.
The Sharpen filters are direct opposites of the Blur filters. These filters attempt to focus soft images by increasing the contrast of adjacent pixels. You can have moderate success with sharpening, but be careful not to oversharpen or you will get distortion such as grain and pixelization.
Sharpen and Sharpen More
The Sharpen and Sharpen More filters offer an all-or-nothing approach and are not very useful. While they add focus to a selection, they have no controls. The Sharpen More filter applies a stronger effect than the Sharpen filter. Skip these and just use the Unsharp Mask or, better yet, Smart Sharpen.
Sharpen Edges and Unsharp Mask
Sharpen Edges and Unsharp Mask filters help find areas where significant color changes occur and sharpen them. While it has no controls, the Sharpen Edges filter does a good job. It only affects edges, thus preserving overall image smoothness.
The Unsharp Mask filter is an even better way to go. This filter lets you adjust the contrast of edges by producing a lighter and darker line on each side of the edge. This helps add emphasis to edges and produces a very satisfactory result. You'll find detailed instructions on the Unsharp Mask filter in Chapter 11.
The Smart Sharpen filter is new to Photoshop CS2. It has superior sharpening controls not available with the Unsharp Mask filter. It allows you to set the sharpening algorithm and control the amount of sharpening that occurs in the shadow and highlight areas. The Smart Sharpen filter is covered in depth in Chapter 11.
The filters in the Sketch category add texture to images. They are useful for creating a hand-drawn look. Most of these filters rely on the foreground and background colors you have chosen. Experiment with different colors for very different looks.
The Bas Relief filter does a great job of transforming the image to appear carved into stone. You also can control the direction of light and its softness value. Dark areas of the image use the foreground color; light colors use the background color.
Chalk & Charcoal
The Chalk & Charcoal filter creates the look of an artist using chalk and charcoal to form an image. The midtones are turned to gray, the highlights are turned to chalk (in the foreground color), the dark areas charcoal (in the background color).
The Charcoal filter redraws an image, creating a smudged, posterized effect. Charcoal is the foreground color; the paper is the background color. This can create a nice, simplified look that works well in video.
The Chrome filter attempts to look like polished chrome. Adobe recommends using a Levels adjustment after running this filter to get a better look. There are much better third-party effects for chrome, and you can experiment with Layer Styles to achieve metal as well.
Conté crayons are usually very dark or pure white. The Conté Crayon filter uses the foreground for dark areas and the background for light ones. To replicate the traditional look, use a dark red, brown, or black for the foreground color. This filter can also be used as an optional way to achieve a historical-looking sepia tone.
The Graphic Pen filter uses fine strokes to replicate the original image. The foreground color acts as ink; the background color acts as the paper.
The Halftone Pattern filter is useful for stylizing an image. You can choose between dots, circles, and lines. This can be used to create a scan line look or a unique twist on pixelization. The foreground and background colors are very important. Be sure to use the Fade command on this filter.
The Note Paper filter creates a look of the image being constructed of handmade paper. Its results are marginal, but worth the occasional try.
Photocopy does what its name implies: It makes the image look like you made a photocopy on a 1970s copy machine. Large areas of darkness will copy only around their edges. Midtones tend to drop off to pure black or white. This filter is useful for simplifying a photo for use as a design element.
The Plaster filter simulates a molded image made of plaster. The foreground and background colors are used to colorize the image. Dark areas are raised; light areas are recessed.
Reticulation is a developing technique where the controlled shrinking and distorting of film emulsion generates an image that appears clustered in the shadows and grained in the highlights. This is a nice alternative to a duotone effect.
The Stamp filter creates a woodcut or rubberstamp look. It's a good way to simplify images for use in multilayered compositions. The foreground and background colors are important.
The Torn Edges filter works well on high-contrast images and text. It makes the image appear to be constructed of torn paper. The foreground and background colors then tint the image.
The Water Paper painterly effect looks like paint blotches on fibrous, damp paper. The colors of the source appear to flow and blend. This filter softens the original image.
The Stylize filters work by displacing pixels and adding contrast to edges. Use of the Fade command and blending modes will significantly extend the usefulness of these filters.
The Diffuse filter is very subtle and may take a few passes to be noticed. It attempts to diffuse an image to make the selection look less focused. Normal moves pixels randomly. Darken Only replaces light pixels with darker pixels. Lighten Only replaces dark pixels with lighter pixels. Anisotropic shuffles pixels toward the direction of least change in color.
Emboss gives the appearance of a raised or stamped image. You can specify the angle, height, and amount of color. To better preserve color, fade the filter immediately after running it. You can try Bevel & Emboss Layer Style for greater flexibility.
The Extrude filter creates a 3D texture. You can choose from Blocks or Pyramids, as well as specify the size and depth. This is a nice look for background images; it looks particularly good on simple backgrounds or even solid colors.
The Find Edges filter creates a very nice stroked edge effect. Try blending it to create a cel-shaded cartoon look.
The Glowing Edges filter is an inverse of the Find Edges filter. It also identifies edges, but produces an inverted color scheme. This filter looks best when blended via the Fade command.
The Solarize filter blends a negative and a positive image together. Be sure to use the Fade after running the filter to open it up to more possibilities.
The Tiles filter breaks the image up into tiles. You can specify the size, amount of movement, and what lies beneath.
The Trace Contour filter locates transitions of major brightness areas and thinly outlines them. Each color channel is identified. The effect is designed to simulate contour lines on a map.
The Wind filter creates small horizontal lines to simulate a wind effect. You can choose left or right, as well as three methods: Wind, Blast, and Stagger.
The Texture filters give the appearance of depth in an image. They can be used to make an image appear to be on an organic surface. When run on images, they give the appearance of the image being mapped or repainted on additional surfaces.
The Craquelure filter simulates paint on a plaster surface. It creates cracks that follow the image's contours.
The Grain filter can create regular, soft, sprinkles, clumped, contrasty, enlarged, stippled, horizontal, vertical, or speckle grain. This filter is very useful for stylizing images and backgrounds.
Don't confuse the Mosaic Tiles filter with the more useful Mosaic filter. This filter is similar to Craquelure, but not very useful.
The Patchwork filter can be thought of as an alternate Mosaic filter. It cuts the image into smaller squares filled with the predominant color in that area. The squares have a random depth assigned to them.
The Stained Glass filter simulates stained glass windows. The image is repainted as single-colored cells, outlined in the foreground color. Try layering a filtered copy with an original version.
The Texturizer filter is very diverse, if you have textures. Any flattened grayscale Photoshop format file can be used as a texture. Look in your Photoshop folder or on your installation disc for extra textures.
The Video filters are designed for professional video work. These two are both pretty straightforward, but important to video pros. To learn more about Photoshop and Video, visit www.PhotoshopforVideo.com.
Video frames in a camera are often recorded between 24 and 30 frames per second. These still images create movement when played back. For smoother motion, adjacent frames are blended together or interlaced.
If you are working with a freeze frame from a video, you may choose to remove interlacing. You can replace the discarded line via interpolation or duplication. Generally speaking, replacing odd or even fields does not matter, but interpolation generates better results than duplication.
Like CMYK color space, video graphics have a narrower gamut. The NTSC Colors filter adjusts the colors of your Photoshop graphic to match the NTSC standard (used by broadcasters in North America). Unfortunately, this filter hard clips color information that falls outside of safe color range for the NTSC model. Instead of gently fading these colors, a hard clip is quite visible. If you're using Photoshop CS2 (or later), be sure to try the Broadcast Saturation action (part of the Video set).
The Other filters did not fit into any of the other categories. So the descriptive term other was put through months of development and testing. You can use these filters to make your own filters, modify masks, or adjust colors. It's a true grab bag, but an important mix.
Some users like the Custom filter, but it's pretty tough to use. Essentially, you are multiplying, adding, and subtracting color information. Look up the instruction in the Help Center, and feel free to explore.
The High Pass filter is used to keep edge details within the specified radius, while suppressing the rest of the image. The filter is an anti-Gaussian Blur filter.
The HSB/HSL filter allows you to convert between RGB, HSB, and HSL mode. This is helpful if an image is being wrongly interpreted. If run on an image that does not need it, you will get severe color shifting.
Minimum and Maximum
The Minimum and Maximum filters are used for modifying masks or alpha channels. The Minimum filter acts as a matte choker. Black is expanded, whereas white is shrunk. The Maximum filter has the opposite effect as a matte spreader; white is expanded, whereas dark is contracted. These filters can also be run as a different pixelization effect, and produce a nice mosaic look for an image.
You can use the Offset filter to move an image a specified distance, either horizontally or vertically. The pixels can leave an empty place, wrap around to the other side, or continue the color at the edges.