Applying GIMP Filters


Like other image-editing programs, GIMP includes many filters to add dramatic effects to your images. Filters are applied either to the currently selected layer or to a selection within the layer. To apply a filter, right-click the image and choose the relevant menu option. If you don’t like an effect you’ve applied, you can reverse it by selecting Edit ->
Undo, or by pressing Ctrl+Z.

The submenus offer filters grouped by categories, as follows:

Blur: These filters add various kinds of blur to the image or selection. For example, Motion Blur can imitate the effect of photographing an object moving at speed with a slow shutter. Perhaps the most popular blur option is Gaussian Blur, which has the effect of applying a soft and subtle blur.

Enhance: The Enhance effects are designed to remove various artifacts from an image or otherwise improve it. For example, the Despeckle effect will attempt to remove unwanted noise within an image (such as flecks of dust in a scanned image). The Sharpen filter discussed in the previous section is located here, as is Unsharp Mask, which offers a high degree of control over the image-sharpening process.

Distorts: As the name of this category of filters suggests, the effects here distort the image in various ways. For example, Whirl and Pinch allow you to tug and push the image to distort it (to understand what is meant here, imagine printing the image on rubber and then pinching or pushing the surface). This category also contains other special effects, such as Pagecurl, which imitates the curl of a page at the bottom of the picture.

Light and Shadow: Here, you will find filters that imitate the effects that light and shadow can have on a picture, such as adding sparkle effects to highlights or imitating lens flare caused by a camera’s lens.

Noise: This collection of filters is designed to add speckles or other types of artifacts to an image. These filters are offered within GIMP for their potential artistic effects, but they can also be used to create a grainy film effect—simply click Scatter RGB.

Edge-Detect: This set of filters can be used to automatically detect and delineate the edges of objects within an image. Although this type of filter can result in some interesting results that might fall into the category of special effects, it’s primarily used in conjunction with other tools and effects.

Generic: In this category, you can find a handful of filters that don’t seem to fall into any other category. Of particular interest is the Convolution Matrix option, which lets you create your own filters by inputting numeric values. According to GIMP’s programmers, this is designed primarily for mathematicians, but it can also be used by others to create random special effects. Simply input values and then preview the effect.

Combine: Here, you’ll find filters that combine two or more images into one.

Artistic: These filters allow you to add paint effects to the image, such as making it appear as if the photo has been painted in impressionistic brushstrokes or painted on canvas.

Map: These filters aim to manipulate the image by treating it like a piece of paper that can be folded in various ways and stuck onto 3D shapes (a process referred to as mapping). Because the image is treated as if it were a piece of paper, it can also be copied, and the copies placed on top of each other to create various effects.

Render: Here, you’ll find filters designed to create new images from scratch, such as clouds or flame effects. They obliterate anything that was previously underneath on that particular layer or within that selection, and the original image has no bearing on what is generated by the filter.

Web: Here, you can create an image map for use in a web page. An image map is a single image broken up into separate hyperlinked areas, typically used on a web page as a sophisticated menu. For example, an image map is frequently used for a geographical map on which you can click to get more information about different regions.

Animation: These filters aim to manipulate and optimize GIF images, which are commonly used to create simple animated images for use on web sites.

Alpha to Logo: These filters are typically used to create special effects for text. They are quite specialized and require an in-depth knowledge of how GIMP works, particularly the use of alpha channels.

Decors: These filters are used to add decorations and special effects to an image. Filters include Coffee Stains (which actually adds coffee stains to your image), Old Photo, Round Corners, and Bevel Borders.

Source of Information : Apress Beginning Ubuntu Linux 3rd Edition


Subscribe to Computing Tech

Enter your email address:

Delivered by FeedBurner

Add to Technorati Favorites Top Blogs