When you click your image editor’s Effects menu, do you wonder what all of those options are for? Perhaps you have tried a few of those automated filters, such as Sharpen, but you have hesitated to try any of the others because you don’t know how to use them.

If you want to learn more about the filters and effects available, take a few minutes to peruse this article and learn about useful filters that enhance and correct your images. While you’re at it, you can learn about some fun and interesting effects, too.

Before We Begin. Most image editors on themarket include filters that you can use to quickly enhance and transform your images. With just a few clicks, you can take a photo and sharpen it, make it resemble a watercolor painting, or even add a spotlight effect to it.

The location of the filters varies depending upon the software that you use. For example, Photoshop LE (Limited Edition) places filters in the Filters menu, whereas Paint Shop Pro and PhotoDeluxe place filters in the Effects menu. For simplicity, we’ll use the term “Effects menu” throughout this article, unless we are discussing a specific editor that uses a different convention.

Also, keep in mind the following recommendations:

•If you apply a filter to your image and decide you don’t like that filter, click Undo in the Edit menu (or press CTRL-Z). If you return to the filter setting and adjust it without clicking Undo first, the editor builds on the adjusted image.

•Be sure to use the thumbnail previews that most of the filters offer. This decreases how often you have to click Undo in order to reverse the effect of a filter.

•Whenever possible, avoid using automated filters (those that do not offer settings you can adjust). You get better results from filters you can control.

• Keep in mind how you want to publish the image file. If your final destination for your image is a print medium, print the image to verify that the quality is acceptable. If you plan to use the image on a Web site, remember to keep the file size to a minimum.

Now that we have covered some of the ground rules, let’s get started.

Enhance, Adjust & Correct Photos. The most frequently used filters are the ones that improve and enhance the look of an image. Among other things, filters can sharpen, blur, remove speckles, and add lighting to the photo. Let’s begin with Sharpen, which is probably the most useful filter for improving images.

Sharpen the details. Most image editors offer several options for sharpening images. For example, Paint Shop Pro and Photoshop LE offer Sharpen, Sharpen More, and Unsharp Mask. All of these options bring out the details in your image, but they cannot add detail that is not already there. If the original image is more than a little out of focus, for example, sharpening won’t fully eliminate the fuzziness.

Sharpen and Sharpen More are the easiest and quickest means of sharpening images. Both options apply an automatic sharpening filter to the image, with Sharpen More being the stronger of the two.

To automatically sharpen an image, first open the image in your editing software. Next, click your editor’s Effects menu, point to Sharpen, and select either Sharpen or Sharpen More. Continue clicking Sharpen or Sharpen More until you are satisfied with how your image looks on-screen. If you over do the sharpening, use the Undo option in the Edit menu.

If you want more control over the sharpening process, use the Unsharp Mask feature. This feature lets you define the distribution of sharpening and the thickness of the edges. Edges are areas of significant color change within the image. When you select Unsharp Mask, there are generally three options available for you to tweak: Strength, Radius, and Clipping (sometimes called Threshold). Strength controls how intensity the effect is applied to the image, Radius dictates how large an area beyond the edges is affected, and Clipping indicates the fineness of the edge detection.

As a baseline, set the Strength to 100, Radius to 1.0, and Clipping between 5 and 10. Adjust and preview the settings until you are satisfied with the result.

Create misty for me. You can use the blur filters for a wide variety of effects, ranging from a little bit of blur for that foggy or misty look to a lot of blur for complete distortion. In addition, blur filters can add motion to an image, giving the illusion of movement in the picture.

Similar to the sharpen filters, blur filters come in a variety of styles. Common blur filters include Blur, Blur More, Gaussian Blur, and Motion Blur. The Blur and Blur More filters are automatic filters that do not offer much control over the level of blurring. If your editor offers it, a better choice is the Gaussian Blur option.

The Gaussian Blur effect uses a formula, commonly known as the bell curve, which the mathematician Karl Friedrich Gauss devised. The curve determines the distribution of the blur effect.

When you select Gaussian Blur from the Blur options in your editor’s Effects menu, a dialog box displays. The dialog box includes a Radius slider. For a softening effect, adjust the slider to 1.5 or less. For a more pronounced effect, use values between 1.5 and 5. Values more than 5 completely distort the image. Figure 1 shows the result of the Gaussian Blur at a Radius of 1.

Add perspective. Most images have a focal point. As professional photographers know, you can blur the background to add emphasis to the focal point and depth to the image. This technique also augments the effect of sharpening filters. This is especially helpful when your original image is too blurry to be corrected completely through the sharpening filters.

The first step is to select the area of the image that you want to remain in focus. Zoom in to enlarge the image to more precisely select your focus area. Next, click your editor’s freehand or lasso selection tool, which lets you use the mouse as a pencil to outline the selection area. If you have an option to feather the selection, set Feathering at about 5. This softens the line between the focused and blurred areas.

After you define the selection area, the next step is to inverse your selection. Inverse is an option often found in your editor’s Select menu. After you click the Inverse option, select Blur from the Effects menu and apply the type and level of blur that you want. For best results, use the Gaussian Blur option if your editor offers it, with a Radius setting of 6 or less. Figure 2 illustrates using this technique.

Eliminate graininess. Your digital images aren’t always crystal clear. They can appear grainy when the subject is in low light or is too close to the camera. When a picture is grainy, the picture looks as if small dots are scattered throughout the image; these dots are undesirable when you want a clear, well-defined image.

To eliminate this problem, most image editors include a Despeckle filter. This filter is normally in the Noise category of the Effects menu.

Despeckle identifies the edges in the image and then blurs everything but those edges in order to protect detail. To apply the Despeckle filter, open the image, point to Noise in the Effects menu, and click Despeckle. Because this is an automatic filter, you should see the effect immediately.

Add lighting. Most of us don’t always have the time, resources, or expertise to set up lighting before we snap a digital image. Thankfully, you can add lighting to an existing image through the magic of the lighting filter.

With this feature, you can mimic one or more lights, vary the degree of intensity, select different colors, and control the size and shape of the lighting. Figure 3 illustrates how lighting effects can enhance an image and create a focal point.

The steps for using the lighting filter depend upon the image editing software that you are using. For illustration purposes, we’ll use Photoshop LE. (For specific steps in other editors, refer to the editor’s documentation.)

To begin, open the image in Photoshop LE, click the Filters menu, point to Render, and click Lighting Effects. The Lighting Effects dialog box displays. Position the light by dragging the center to the location that you desire. You can also narrow and widen the light by dragging the handles on the sides.

After you position the light, you can use the Intensity and Focus sliders to control the brightness and scope of the light beam. If you want to change the color of the light, click the large square to the right of the Intensity and Focus sliders. Clicking this box brings up a window where you can pick colors. If you want to add a light to your image, drag the light bulb beneath the preview window to the desired location.

The Lighting dialog box in Photoshop LE also includes options for changing the overall look of the image (the Properties area) as well as some preset lighting configurations (the Style area). Experiment with these settings to see how they affect your image.

Clean up JPEGs. A number of image editors offer tools to help you improve the appearance of JPEG (Joint Photographic Experts Group) images. The JPEG format uses a compression formula to significantly decrease the size of an image file.

The JPEG compression process can yield jaggies, small, block-like areas in an image. The problem can be exacerbated if you enlarge the JPEG image. To smooth this unevenness, you can use a filter such as JPEG Artifact Removal in Paint Shop Pro or JPEG Clean Up in PhotoDeluxe.

For demonstration purposes, we will work with the filter in Paint Shop Pro. To begin, load the image, click Effects, point to Enhance Photo, and click JPEG Artifact Removal. A dialog box displays with options for Strength (Low, Normal, High, or Maximum) and Restore Crispness.

As a baseline, you should start with Normal for Strength and 50 for Restore Crispness. The Strength option dictates the level of automatic correction, whereas the Restore Crispness option controls how much detail the filter should try to re-create. Adjust these levels until you are satisfied with the effect on the image. Note that high Restore Crispness levels may cause small dots to appear in the image.

Distort, Texturize & Stylize. You will most often use your filters for correcting and enhancing photos; however, most image editors offer considerably more filters for use in distorting images. These filters are fun to experiment with and can give your images an interesting, graphics-art look. However, make sure that you do not go overboard with the use of these filters.

For ease of discussion, we’ve loosely classified these filters as distortion, artistic, texture, and noise filters. Your image editor may or may not use these specific categories. In addition, the types of filters that are available in each image editor can vary greatly. However, most editors include at least a few filters in each category.

Distort it. Distortion filters change the shape of an image, transforming the image into a disfigured version of the original (without harming the subject). For example, you can twirl the image, give it a pinched look, make it look wavy, or even add curly-Qs. See Figure 4 for some examples.

Two common distortion effects that you might experiment with are collapsing the image (known as the Pinch effect) and expanding the image (known as the Punch effect). In Paint Shop Pro, these effects are separate options found under the Geometric Effects on the Effects menu. After you click Pinch or Punch, a dialog box displays with sliders that let you control the level of the effect.

In Photoshop LE, click the Filter menu, point to Distort, and click Pinch. The Pinch dialog box includes a slider that controls pinch and punch, as well as a graphical representation of the currently selected level.

Add an artistic effect. The artistic filters give your image the illusion of being created with media such as colored pencil, charcoal, pastels, pencil, sponge, and watercolor. Most image editors place these filters in the Artistic category within the Effects menu. Some editors offer additional artistic filters or sprinkle them among other categories. For example, Photoshop LE offers Artistic, Sketch, and Brush Strokes filters.

Artistic effects that you might find interesting include the Colored Pencil and Sponge effects (Figure 5). We will use Photoshop LE to illustrate how you should apply these effects to an image.

To use the Colored Pencil filter, open your image and click the Filters menu. Point to Artistic and then click Colored Pencil. The dialog box that displays includes three settings.

Pencil Width dictates the width for crosshatching, the parallel shaded lines that give the image a penciled look. Use smaller numbers if less crosshatching is desired.

For Stroke Pressure, use lower numbers for more background and higher numbers to show more of the image.

Paper Brightness sets the color of the background, or paper. Use larger numbers for brighter or white paper and lower numbers for darker paper.

To use the Sponge filter in Photoshop LE, open your image, click Filters, point to Artistic, and then click Sponge. The dialog box that displays includes three settings: Brush Size, Definition, and Smoothness. For Brush Size, use smaller numbers for more detail. The Definition setting controls the level of color blending. Larger numbers produce less blending. Smoothness controls the level of the sponging effect. Use a higher number for a more pronounced sponge look.

Give it texture. Similar to the artistic effects, and sometimes even intermingled with them, are a group of filters that add texture to an image.

Texture effects can make an entire image or a selection of an image appear as though it has been imprinted on a recognizable material, such as burlap, canvas, bricks, or leather. These filters are generally located under Texture in the Effects menu, and you can use them to create an abstract version of the original image.

Also in this category of 3D effects are edge filters. These filters add emphasis to the edges of an image. Emboss, glowing edges, colored edges, and trace contour are some examples. Edge filters can be found in your image editor’s Stylize filters or combined with the Artistic or Texture filters. For examples of texture and edge effects, see Figure 6.

In addition to the wide assortment of texture filters, some image editors also include a texturizer. A texturizer is an editing tool that lets you import additional textures, which you can create yourself. The additional texture is simply a graphic or image file that has some type of textured pattern.

In Photoshop LE, for example, Texturizer is an available option when you select Texture from the Filters menu. The Texturizer dialog box includes a Texture drop-down list that lets you choose from different textures that come with the image editor, such as Burlap, Canvas, and Sandstone.

If you wanted a tree bark effect, however, you need to snap an image of tree bark, open the image in Photoshop LE, click Save As, and then choose to save it in Photoshop format (the required format for Photoshop LE’s Texturizer). To then use the tree bark texture, click Load Texture in the Texturizer’s Texture drop-down list and then select the image file of the tree bark.

Crank up the noise. As we discussed previously, you can use the filters that are in the noise category to remove graininess and speckles from your images. You can also use the filters in this category to do just the opposite: add noise to your images. Noise is simply a sprinkling of very small dots over an image. Depending upon the image editor, the dots can be a specific color (monochromatic) or a variety of colors.

You can use noise for a number of purposes. Adding noise to an entire image gives it a grainy texture-an interesting effect by itself and one that adds interest when applied before another filter, such as a blur filter. Noise can also make an image look older, especially if you change the image to grayscale and tint it first to make it resemble an old-fashioned photo. In addition, if you combine portions of different images that have varying levels of graininess, you can add noise to selected areas to even out the differences.

To add noise to your image, click Noise on the Effects menu and then click Add. A dialog box displays with settings to control the level and distribution of the noise. Unless you want a lot of clutter, a lower setting works best.

Make Time To Filter. If you understand how to use filters, the quality of your digital images will definitely improve. Techniques such as sharpening, blurring the background, adding lighting, and eliminating graininess are practical and easy to do. Although you might not use all of the filters your editor offers, at the very least, most images can benefit from these corrective filters. What’s more, most of us can think of some fun ways to use some of the less practical but more creative filters.