如何在Android中將彩色圖像製作成黑白色

Question

我想知道如何將彩色圖像（我從網上下載）轉換爲黑白圖像，當我在android中將其顯示給用戶時。 任何人都可以在你的任何Android工作中發現這個要求。請告訴我。

感謝 拉克什曼

Answer 1

嗨，你可以使用對比度使圖像黑N白。

查看代碼..

public static Bitmap createContrast(Bitmap src, double value) { 
    // image size 
    int width = src.getWidth(); 
    int height = src.getHeight(); 
    // create output bitmap 
    Bitmap bmOut = Bitmap.createBitmap(width, height, src.getConfig()); 
    // color information 
    int A, R, G, B; 
    int pixel; 
    // get contrast value 
    double contrast = Math.pow((100 + value)/100, 2); 

    // scan through all pixels 
    for(int x = 0; x < width; ++x) { 
     for(int y = 0; y < height; ++y) { 
      // get pixel color 
      pixel = src.getPixel(x, y); 
      A = Color.alpha(pixel); 
      // apply filter contrast for every channel R, G, B 
      R = Color.red(pixel); 
      R = (int)(((((R/255.0) - 0.5) * contrast) + 0.5) * 255.0); 
      if(R < 0) { R = 0; } 
      else if(R > 255) { R = 255; } 

      G = Color.red(pixel); 
      G = (int)(((((G/255.0) - 0.5) * contrast) + 0.5) * 255.0); 
      if(G < 0) { G = 0; } 
      else if(G > 255) { G = 255; } 

      B = Color.red(pixel); 
      B = (int)(((((B/255.0) - 0.5) * contrast) + 0.5) * 255.0); 
      if(B < 0) { B = 0; } 
      else if(B > 255) { B = 255; } 

      // set new pixel color to output bitmap 
      bmOut.setPixel(x, y, Color.argb(A, R, G, B)); 
     } 
    } 

    return bmOut; 
} 

坐落在馬託通話雙值50。例createContrast(Bitmap src, 50)

Answer 2

使用內置的方法：

public static Bitmap toGrayscale(Bitmap srcImage) { 

    Bitmap bmpGrayscale = Bitmap.createBitmap(srcImage.getWidth(), srcImage.getHeight(), Bitmap.Config.ARGB_8888); 

    Canvas canvas = new Canvas(bmpGrayscale); 
    Paint paint = new Paint(); 

    ColorMatrix cm = new ColorMatrix(); 
    cm.setSaturation(0); 
    paint.setColorFilter(new ColorMatrixColorFilter(cm)); 
    canvas.drawBitmap(srcImage, 0, 0, paint); 

    return bmpGrayscale; 
}