A technique of making fonts look smoother on screen by using blended colours in the pixels around the edges of
letters. It fools the eye into thinking that the edges are sharper than they really are.
You can get W2K/XP
to anti-alias with Start ⇒ Control Panel ⇒ Display ⇒ Effects ⇒ Smooth
edges of screenfonts. You can get Vista to anti-alias with Start ⇒ Control Panel
⇒ System and Maintenance ⇒ Performance Information and Tools ⇒ Adjust Visual Effects (on left)
⇒ smooth edges of screen fonts.
. You can get Vista
to anti-alias with Start ⇒ Control Panel ⇒ System and Maintenance ⇒
Performance Information and Tools ⇒ Adjust Visual Effects (on left) ⇒ smooth edges of screen
With an LCD (Liquid Crystal Display) monitor, you want subpixel anti-aliasing called ClearType. To turn it on click Start ⇒ Control Panel ⇒ Appearance and Personalization ⇒ Personalization ⇒ Windows
color and appearance ⇒ Open classic colour and appearance ⇒ Effects ⇒ ClearType.
Without anti-aliasing, you will see jagged diagonal lines especially in the large sizes of spidery fonts with
thin diagonal lines (e. g. Bodoni, Book Antiqua, Garamond, Serif and Zapf Calligraphic) especially on the capital
W. Sun, even when anti-aliasing, pays no attention to the font rendering hints. This why small font sizes are so
grungy looking. Anti-aliasing is primarily to make large font sizes look better.
What Does Anti-aliasing Look Like?
You can compare the same fonts anti-aliased and plain using the FontShower for Swing amanuensis which will display fonts in various sizes and
colours with and without anti-aliasing and in the FontShower for AWT Applet in canvas mode. You are certain to see fonts without
anti-aliasing in the FontShower for AWT Applet in
canvas mode under W95/W98/Me/NT/W2K. You are certain to see anti-aliasing in the FontShower for Swing under XP/W2003/Vista/W2008/W7-32/W7-64/W8-32/W8-64. The font where the differences are most obvious is DPCustomMono2.
How Anti-Aliasing looks
The further back you stand, the more the samples look alike. Anti-aliasing is a similar sort of blurring that
ironically creates the illusion of sharpness.
Several influences combine to decide whether you will get anti-aliasing:
- Whether your OS/Windowing system supports anti-aliasing.
- Whether you have anti-aliasing turn on system wide.
- Whether your browser is turning on anti-aliasing.
- Whether the program is turning on anti-aliasing.
- Whether the font supports anti-aliasing.
- Whether your text contains unusual characters. Some will turn off anti-aliasing.
Anti-aliasing in Java version 1.2
To anti-alias fonts in AWT (Advanced Windowing Toolkit), you have to go through a gambit like this in your Canvas
There is another technique that uses an undocumented Sun
It won’t do you any good to override the paint method of a peered
Component such as Label, TextField or TextArea since the rendering is handled by the peer.
Whether they are anti-aliased is determined by the OS (Operating System) Control Panel.
Anti-aliasing in Java version 1.3
Anti-aliasing in Swing is similar to AWT, except that you override paintComponent
instead of paint.
Smooth Metal LAF (Look And Feel) adds
anti-aliasing to various Sun LAFs (Look And Feels).
WrapLF is a LAF that lets you insert your own
Anti-aliasing in Java version 1.5
In Java version 1.5 you don’t have to override paint
Since Java version 1.5, it is possible to set the system property globally with swing.aatext=true. You can do that with java.exe
-Dswing.aatext=true on the command line. Unfortunately the results are not always desirable. Sometimes
small fonts look worse anti-aliased.
Anti-aliasing in Java version 1.6
The Java 1.6, has yet another anti-aliasing scheme, one that allows sub-pixel anti-aliasing that takes advantage
of the geometry of the tiny red, green and blue phosphor dots on a CRT (Cathode Ray Tube), or the equivalent dots on an LCD panel,
that make up each pixel. Microsoft uses a scheme like this in Vista
they call ClearType. In Java version 1.6 there is a
system property called awt.useSystemAAFontSettings you can
use to control anti-aliasing. Possible values include:
In Java version 1.6 or later there are also new values to use in setRenderingHints key and value, including VALUE_ANTIALIAS_OFF to
turn anti-aliasing off.
use ClearType style sub-pixel anti-aliasing.
no anti-aliasing. Fast with jaggies.
Gnome Best shapes/Best contrast. Not available in Windows.
Windows standard anti-aliasing.
- Rendering character \u0e3f in a JTextArea
inhibits antialiasing, ditto \ufdfc. \u0e3f
is a Thai Baht currency sign like a capital B with a line through it. \ufdfc
is the Yemeni Rial currency sign. It looks like Arabic script. Using one of these characters turns off
anti-aliasing for the entire JTextArea. They seem to have no such effect in AWT with
drawString or with TextArea. This strange behaviour has
been observed both in Win2K and Linux.
I reported this to Sun and they explained the anomaly is a feature.
Internally when Swing sees a Thai or Arabic character, it switches to using a TextLayout for rendering. A TextLayout is created with a
FontRenderContext, and the anti-aliasing Component of
that FontRenderContext is applied when rendering too. In other words the usual
anti-alias gambit does not work because it is anti-aliasing the wrong Component
when you have Thai or Arabic characters.
- Java version 1.6 defaults its anti-aliasing to whatever the OS desktop setting is, making it behave like AWT peered
Oracle’s Javadoc on RenderingHints
class : available:
Oracle’s Technote Guide on anti-aliasing