Graphics Design for Beginners - Blur Filters
By Stephen Bucaro
A filter is a complex mathematical algorithm that is applied to the pixel
data in an image. There are filters to modify the color of an image, to enhance
an image, to distort an image, and to create many other effects. The blur filter,
as its name implies, is used to make an image more blurry. Why would you want to
make an image blurry?
• To add artistic effects. For example to add the impression of a hazy autumn
afternoon to a scenery picture, or to soften a shadow.
• To hide information. For example to hide an address or license plate number in a picture.
• To highlight part of an image. For example to highlight a foreground object
in a picture, you can blur the background. In an image used for educational
purposes, you can blur a picture of an object - except for the feature you are
referring to in the instruction.
• For legal reasons. For example if a trademark appears in a picture. You can
blur the trademark to make it unrecognizable and avoid infringement issues. If
your picture shows a person in the background and it's use might infer that the
person endorses a particular product. You can blur the persons face to make them
unrecognizable to avoid a law suet based upon using their likeness for profit.
In this article I show you how to use the various blur filters on your
images. I'll use the GIMP image editing program. GIMP stands for "GNU Image
Manipulation Program", GNU standing for GNU General Public License. GIMP is an
image editing program on the level of Photoshop but without the $800.00 price
tag, in fact it's totally free. GIMP was originally created for Linux, but is
now available for Windows.
Download GIMP for Windows from:
Similar to most open-source software, you can't just install GIMP by
executing a single setup program, you need to download three files and install them separately.
- GIMP for Windows (7.8 MB)
- GTK+ 2 Runtime Environment (3.7 MB)
- GIMP Help (22 MB)
Extract the three zip files into a new folder under Program Files
(for example named "GIMP"), then double-click each setup file, starting with the
GTK (GIMP Tool Kit), then GIMP, and then Help. This is the order in which the
components look for each other as you install and use them.