如何將像素數據轉換爲java中的灰度圖像？

Question

我已經灰色像素，但不知道要創建灰度圖像

Answer 1

在Java中的蒼蠅（從http://technojeeves.com/joomla/index.php/free/89-create-grayscale-image-on-the-fly-in-java）

import java.awt.*; 
import java.awt.color.*; 
import java.awt.image.*; 

import java.io.*; 

import javax.imageio.ImageIO; 


public class BMP { 
/** 
* (Testing only) 
*/ 
public static void main(String[] args) throws Exception { 
    BMP.makeMeCross(args[0]); 
} 

/** 
* 
* @param filename The file name for the 'crosshair' image 
* 
* @throws IOException If the file could not be written to by ImageIO 
*/ 
public static void makeMeCross(String filename) throws IOException { 
    int sz = 101; 
    byte[] buffer = new byte[sz * sz]; 

    for (int i = 0; i < sz; i++) { 
     for (int j = 0; j < sz; j++) { 
      // Make a 'crosshair' pattern 
      buffer[(i * sz) + j] = ((j == 50) || (i == 50)) ? (byte) 255 : 0; 
     } 
    } 

    ImageIO.write(BMP.getGrayscale(101, buffer), "PNG", new File(filename)); 
} 

/** 
* 
* @param width The image width (height derived from buffer length) 
* @param buffer The buffer containing raw grayscale pixel data 
* 
* @return THe grayscale image 
*/ 
public static BufferedImage getGrayscale(int width, byte[] buffer) { 
    int height = buffer.length/width; 
    ColorSpace cs = ColorSpace.getInstance(ColorSpace.CS_GRAY); 
    int[] nBits = { 8 }; 
    ColorModel cm = new ComponentColorModel(cs, nBits, false, true, 
      Transparency.OPAQUE, DataBuffer.TYPE_BYTE); 
    SampleModel sm = cm.createCompatibleSampleModel(width, height); 
    DataBufferByte db = new DataBufferByte(buffer, width * height); 
    WritableRaster raster = Raster.createWritableRaster(sm, db, null); 
    BufferedImage result = new BufferedImage(cm, raster, false, null); 

    return result; 
} 
} 

Answer 2

有值得一javax.swing.GrayFilter創建灰度圖像看看這個目的。它可以像這樣使用：

Icon icon = myLabel.getIcon(); 
Image img = gc.createCompatibleImage(icon.getIconWidth(), icon.getIconHeight(), Transparency.TRANSLUCENT); 
icon.paintIcon(this, img.getGraphics(), 0, 0); 
img = GrayFilter.createDisabledImage(img); 
myLabel.setIcon(new ImageIcon(img));