FULL PRODUCT VERSION :
java version "1.4.2_03"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.2_03-b02)
Java HotSpot(TM) Client VM (build 1.4.2_03-b02, mixed mode)
ADDITIONAL OS VERSION INFORMATION :
Microsoft Windows 2000 [Version 5.00.2195]
(Also occurs on Solaris)
A DESCRIPTION OF THE PROBLEM :
I have an application used to render maps that draws graphics into a BufferedImage that uses an 8 bit indexed color model. Rendering hints are used to enable anti-aliasing and to disable dithering.
In J2SE 1.3.1_06, everything worked correctly, and the generated maps contained solid colors.
In J2SE 1.4.1 and 1.4.2, polygons are filled with dithered colors for most of the colors in the palette used.
Interestingly, if anti-aliasing is disabled, no dithering occurs.
STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Run the attached sample code using J2SE 1.3.1_06 and J2SE 1.4.2_03, and observe the differences.
EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
The sample code draws a set of squares in various colors. They are all colors that exist in the indexed color model, and so all of them should be rendered as solid (not dithered) colors.
ACTUAL -
A large number of the squares are rendered using a dithering pattern.
REPRODUCIBILITY :
This bug can be reproduced always.
---------- BEGIN SOURCE ----------
package sandbox;
import java.awt.*;
import java.awt.image.*;
public class ImageDitheringProblem extends Frame
{
public static int[] COLORS = new int[]{
0xFFFFFF, 0xC0C0C0, 0x808080, 0x000000,
0xFF0000, 0xFFFF00, 0x00FF00, 0x00FFFF,
0x0000FF, 0xFF00FF, 0x800000, 0x808000,
0x008000, 0x008080, 0x000080, 0x800080,
0x500000, 0x700000, 0x900000, 0xC00000,
0xE00000, 0xFF0000, 0xFF2020, 0xFF4040,
0xFF5050, 0xFF6060, 0xFF8080, 0xFF9090,
0xFFA0A0, 0xFFB0B0, 0xFFD0D0, 0x501400,
0x701C00, 0x902400, 0xA02800, 0xC03000,
0xE03800, 0xFF4000, 0xFF5820, 0xFF7040,
0xFF7C50, 0xFF9470, 0xFFA080, 0xFFB8A0,
0xFFC4B0, 0xFFDCD0, 0x502800, 0x603000,
0x804000, 0xA05000, 0xB05800, 0xD06800,
0xE07000, 0xFF8000, 0xFF9830, 0xFFA850,
0xFFB060, 0xFFC080, 0xFFD0A0, 0xFFD8B0,
0xFFE8D0, 0x503C00, 0x604800, 0x806000,
0x906C00, 0xA07800, 0xC09000, 0xD09C00,
0xF0B400, 0xFFC000, 0xFFD040, 0xFFD860,
0xFFDC70, 0xFFE490, 0xFFECB0, 0xFFF4D0,
0x505000, 0x606000, 0x707000, 0x909000,
0xA0A000, 0xB0B000, 0xC0C000, 0xF4F400,
0xF0F000, 0xFFFF00, 0xFFFF40, 0xFFFF70,
0xFFFF90, 0xFFFFB0, 0xFFFFD0, 0x305000,
0x3A6000, 0x4D8000, 0x569000, 0x60A000,
0x73C000, 0x7DD000, 0x90F000, 0x9AFF00,
0xB3FF40, 0xC0FF60, 0xCDFF80, 0xD3FF90,
0xE0FFB0, 0xEDFFD0, 0x005000, 0x006000,
0x008000, 0x00A000, 0x00B000, 0x00D000,
0x00E000, 0x00FF00, 0x50FF50, 0x60FF60,
0x70FF70, 0x90FF90, 0xA0FFA0, 0xB0FFB0,
0xD0FFD0, 0x005028, 0x006030, 0x008040,
0x00A050, 0x00B058, 0x00D068, 0x00F470,
0x00FF80, 0x50FFA8, 0x60FFB0, 0x70FFB8,
0x90FFC8, 0xA0FFD0, 0xB0FFD8, 0xD0FFE8,
0x005050, 0x006060, 0x008080, 0x009090,
0x00A0A0, 0x00C0C0, 0x00D0D0, 0x00F0F0,
0x00FFFF, 0x50FFFF, 0x70FFFF, 0x80FFFF,
0xA0FFFF, 0xB0FFFF, 0xD0FFFF, 0x003550,
0x004B70, 0x006090, 0x006BA0, 0x0080C0,
0x0095E0, 0x00ABFF, 0x40C0FF, 0x50C5FF,
0x60CBFF, 0x80D5FF, 0x90DBFF, 0xA0E0FF,
0xB0E5FF, 0xD0F0FF, 0x001B50, 0x002570,
0x001C90, 0x0040C0, 0x004BE0, 0x0055FF,
0x3075FF, 0x4080FF, 0x508BFF, 0x70A0FF,
0x80ABFF, 0x90B5FF, 0xA0C0FF, 0xC0D5FF,
0xD0E0FF, 0x000050, 0x000080, 0x0000A0,
0x0000D0, 0x0000FF, 0x2020FF, 0x1C1CFF,
0x5050FF, 0x6060FF, 0x7070FF, 0x8080FF,
0x9090FF, 0xA0A0FF, 0xC0C0FF, 0xD0D0FF,
0x280050, 0x380070, 0x480090, 0x6000C0,
0x7000E0, 0x8000FF, 0x9020FF, 0xA040FF,
0xA850FF, 0xB060FF, 0xC080FF, 0xC890FF,
0xD0A0FF, 0xD8B0FF, 0xE8D0FF, 0x500050,
0x700070, 0x900090, 0xA000A0, 0xC000C0,
0xE000E0, 0xFF00FF, 0xFF20FF, 0xFF40FF,
0xFF50FF, 0xFF70FF, 0xFF80FF, 0xFFA0FF,
0xFFB0FF, 0xFFD0FF, 0x500028, 0x700060,
0x900048, 0xC00060, 0xE00070, 0xFF008A,
0xFF2090, 0xFF40A0, 0xFF50A8, 0xFF60B0,
0xFF80C0, 0xFF90C8, 0xFFA0D0, 0xFFB0D8,
0xFFD0E8, 0x000000, 0x101010, 0x202020,
0x303030, 0x404040, 0x505050, 0x606060,
0x707070, 0x909090, 0xA0A0A0, 0xB0B0B0,
0xC0C0C0, 0xD0D0D0, 0xE0E0E0, 0xF0F0F0};
public static void main(String [] args)
{
Frame f = new ImageDitheringProblem();
f.setSize(640, 480);
f.setVisible(true);
}
public void paint(Graphics g)
{
int width = getSize().width;
int height = getSize().height;
// Create an IndexColorModel for the custom palette
IndexColorModel colorModel = new IndexColorModel(8, COLORS.length,
COLORS, 0, false, -1, DataBuffer.TYPE_BYTE);
// Create a BufferedImage that uses the custom color model
BufferedImage image = new BufferedImage(width,
height, BufferedImage.TYPE_BYTE_INDEXED,
colorModel);
// Create a graphics object to render to
Graphics2D graphics = image.createGraphics();
// Disable dithering
graphics.setRenderingHint(RenderingHints.KEY_DITHERING,
RenderingHints.VALUE_DITHER_DISABLE);
// Enable anti-aliasing
graphics.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
// Draw a series of squares in different colors
int colorIndex = 0;
for(int xOffset = 0; xOffset < width - 50; xOffset += 50)
{
for(int yOffset = 0; yOffset < height - 50; yOffset += 50)
{
if(colorIndex < COLORS.length)
{
Color color = new Color(COLORS[colorIndex++]);
graphics.setColor(color);
graphics.fillRect(xOffset, yOffset, 50, 50);
}
}
}
graphics.dispose();
// Display the image
g.drawImage(image, 0, 0, null);
}
}
---------- END SOURCE ----------
CUSTOMER SUBMITTED WORKAROUND :
Disabling anti-aliasing seems to disable the dithering effect. However this is not really an acceptable workaround because graphics within the image then (obviously) take on a jagged appearance.
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Java