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info
文件

Dithering_.txt

来源

See below


目的

该宏采用8位灰度或24位RGB图像，并使用支持的方法执行其中之一。灰度是一种半色调阈值处理，其中灰度（或RGB通道）强度被转换为二进制像素的局部密度。这非常适合在具有二进制输出的设备（例如打印机（灰度））或具有少量颜色（颜色接近）的设备中渲染图像。

对于24位RGB图像，宏您将评估图像的灰度版本或每个RGB通道（颜色通道）。

安装

复制下面的源代码放在其保存到 /Plugins 文件夹中某处名为“Dithering_.txt”的文件中。重新启动 Fiji 或 ImageJ 将显示一个名为“/plugins/dithering”的新命令。

可用方法

实现以下方法（还有其他已几种）：Floyd-Steinberg、Atkinson、Jarvis-Judice-Ninke、Stucki、Bayer_2x2、Bayer_4x4、Bayer_8x8、Clustered_4x4 和 Random。
通过某些比例缩放图像会引入许多α影，因此在调整图像大小后应用缩放至关重要。
当使用小像素显示或打印图像时，可以最好地渲染渲染结果。

以下图像已放大2倍以显示各个像素。

Ditheringmontage

宏代码

// Dithering
// G. Landini at bham. ac. uk
// 17/ May 2009

Dialog.create("/plugins/dithering");
items=newArray("Floyd-Steinberg", "Atkinson", "Jarvis-Judice-Ninke","Stucki",
        "Bayer_2x2", "Bayer_4x4", "Bayer_8x8", "Clustered_4x4", "Random");
doColour = false;

Dialog.addChoice("Method", items);
if (bitDepth==24) Dialog.addCheckbox("Colour dithering", false);
Dialog.show() ;
method=Dialog.getChoice();
if (bitDepth==24)
   doColour=Dialog.getCheckbox();

setBatchMode(true);
w=getWidth();
h=getHeight();
run("Duplicate...", "title="+method);
if (bitDepth == 24 && doColour) {
   run("RGB Stack");
   for (i=1; i<4; i++){
     showProgress(i/4);
     setSlice(i);
     dither(method);
   } 
   run("RGB Color");
}
else{
  if (bitDepth>8 && !doColour) run("8-bit");
  dither(method);
}
setBatchMode(false);

function dither(method) {
 if (method=="Floyd-Steinberg"){
  w1=7/16;
  w2=3/16;
  w3=5/16;
  w4=1/16;
  for (y=0; y<h; y++){
    for (x=0; x<w; x++){
      oldpixel = getPixel(x,y);
      if (oldpixel<128) newpixel=0; else newpixel=255;
      setPixel(x,y, newpixel);
      quant_error = oldpixel - newpixel;
      setPixel(x+1,y, getPixel(x+1,y) + w1 * quant_error);
      setPixel(x-1,y+1, getPixel(x-1,y+1) + w2 * quant_error);
      setPixel(x,y+1, getPixel(x,y+1) + w3 * quant_error);
      setPixel(x+1,y+1, getPixel(x+1,y+1) + w4 * quant_error);
    }
  }
 }
 else if (method=="Atkinson"){
  w1=1/8;
  for (y=0; y<h; y++){
    for (x=0; x<w; x++){
      oldpixel = getPixel(x,y);
      if (oldpixel<128) newpixel = 0; else newpixel=255;
      setPixel(x,y, newpixel);
      quant_error = oldpixel - newpixel;
      setPixel(x+1,y, getPixel(x+1,y) + w1 * quant_error);
      setPixel(x+2,y, getPixel(x+2,y) + w1 * quant_error);
      setPixel(x-1,y+1, getPixel(x-1,y+1) + w1 * quant_error);
      setPixel(x,y+1, getPixel(x,y+1) + w1 * quant_error);
      setPixel(x+1,y+1, getPixel(x+1,y+1) + w1 * quant_error);
      setPixel(x,y+2, getPixel(x,y+2) + w1 * quant_error);
    }
  }
 }
 else if (method=="Jarvis-Judice-Ninke"){
  w7=7/48;
  w5=5/48;
  w3=3/48;
  w1=1/48;
  for (y=0; y<h; y++){
    for (x=0; x<w; x++){
      oldpixel = getPixel(x,y);
      if (oldpixel<128) newpixel = 0; else newpixel=255;
      setPixel(x,y, newpixel);
      quant_error = oldpixel - newpixel;
      setPixel(x+1,y, getPixel(x+1,y) + w7 * quant_error);
      setPixel(x+2,y, getPixel(x+2,y) + w5 * quant_error);
      setPixel(x-2,y+1, getPixel(x-2,y+1) + w3 * quant_error);
      setPixel(x-1,y+1, getPixel(x-1,y+1) + w5 * quant_error);
      setPixel(x,y+1, getPixel(x,y+1) + w7 * quant_error);
      setPixel(x+1,y+1, getPixel(x+1,y+1) + w5 * quant_error);
      setPixel(x+2,y+1, getPixel(x+2,y+1) + w3 * quant_error);
      setPixel(x-2,y+2, getPixel(x-2,y+2) + w1 * quant_error);
      setPixel(x-1,y+2, getPixel(x-1,y+2) + w3 * quant_error);
      setPixel(x,y+2, getPixel(x,y+2) + w5 * quant_error);
      setPixel(x+1,y+2, getPixel(x+1,y+2) + w3 * quant_error);
      setPixel(x+2,y+2, getPixel(x+2,y+2) + w1 * quant_error);
    }
  }
 }
 else if (method=="Stucki"){
  w8= 8/42;
  w7=7/42;
  w5=5/42;
  w4= 4/42;
  w2=2/42;
  w1=1/42;
  for (y=0; y<h; y++){
    for (x=0; x<w; x++){
      oldpixel = getPixel(x,y);
      if (oldpixel<128) newpixel = 0; else newpixel=255;
      setPixel(x,y, newpixel);
      quant_error = oldpixel - newpixel;
      setPixel(x+1,y, getPixel(x+1,y) + w7 * quant_error);
      setPixel(x+2,y, getPixel(x+2,y) + w5 * quant_error);
      setPixel(x-2,y+1, getPixel(x-2,y+1) + w2 * quant_error);
      setPixel(x-1,y+1, getPixel(x-1,y+1) + w4 * quant_error);
      setPixel(x,y+1, getPixel(x,y+1) + w8 * quant_error);
      setPixel(x+1,y+1, getPixel(x+1,y+1) + w4 * quant_error);
      setPixel(x+2,y+1, getPixel(x+2,y+1) + w2 * quant_error);
      setPixel(x-2,y+2, getPixel(x-2,y+2) + w1 * quant_error);
      setPixel(x-1,y+2, getPixel(x-1,y+2) + w2 * quant_error);
      setPixel(x,y+2, getPixel(x,y+2) + w4 * quant_error);
      setPixel(x+1,y+2, getPixel(x+1,y+2) + w2 * quant_error);
      setPixel(x+2,y+2, getPixel(x+2,y+2) + w1 * quant_error);
    }
  }
 }
 else if (method=="Bayer_2x2"){
  d= newArray(2,3,4,1);
  for (i=0; i<d.length; i++)
    d[i]=d[i] * 64 - 1;

  for (y=0; y<h; y++){
    for (x=0; x<w; x++){
      if (getPixel(x,y)>=d[(y%2*2+x%2)])
          newpixel = 255; 
      else 
          newpixel=0;
      setPixel(x,y, newpixel);
    }
  }
 }
 else if (method=="Bayer_4x4"){
  d= newArray(0.1250, 1.0000, 0.1875, 0.8125, 0.6250, 0.3750, 0.6875,
     0.4375,0.2500, 0.8750, 0.0625, 0.9375, 0.7500, 0.5000, 0.5625, 0.3125);
  for (i=0; i<d.length; i++)
    d[i]*=255;
  for (y=0; y<h; y++){
    for (x=0; x<w; x++){
      if (getPixel(x,y)>=d[(y%4*4+x%4)])
          newpixel = 255; 
      else 
          newpixel = 0;
      setPixel(x,y, newpixel);
    }
  }
 }
 else if (method=="Bayer_8x8"){
  d= newArray(1, 33,  9, 41, 3,  35, 11, 43, 49, 17, 57, 25, 51, 19, 59, 27, 13, 45, 5, 
    37, 15, 47, 7, 39, 61, 29, 53, 21, 63, 31, 55, 23, 4, 36, 12, 44, 2, 34, 10, 42, 52,
    20, 60, 28, 50, 18, 58, 26, 16, 48, 8, 40, 14, 46, 6, 38, 64, 32, 56, 24, 62, 30,
    54, 22);

  for (i=0; i<d.length; i++)
    d[i]=d[i] * 4 - 1;

  for (y=0; y<h; y++){
    for (x=0; x<w; x++){
      if (getPixel(x,y)>=d[(y%8*8+x%8)])
          newpixel = 255; 
      else 
          newpixel = 0;
      setPixel(x,y, newpixel);

    }
  }
 }
 else if (method=="Clustered_4x4"){
  d= newArray(0.7500, 0.3750, 0.6250, 0.2500, 0.0625, 1.0000, 0.8750, 0.4375,
    0.5000, 0.8125, 0.9375, 0.1250, 0.1875, 0.5625, 0.3125, 0.6875);
  for (i=0; i<d.length; i++)
    d[i]*=255;

  for (y=0; y<h; y++){
    for (x=0; x<w; x++){
      if (getPixel(x,y)>=d[(y%4*4+x%4)])
          newpixel = 255; 
      else 
          newpixel = 0;
      setPixel(x,y, newpixel);
    }
  }
 }
else if (method=="Random"){
  w1=1/8;
  for (y=0; y<h; y++){
    for (x=0; x<w; x++){
      if(getPixel(x,y)> random*255)
        setPixel(x,y, 255);
      else   
        setPixel(x,y, 0);
    }
  }
 }
}