使用Android拍摄黑白照片（黑白）

如果您希望图像为1位黑白，则可以使用简单的（慢速）阈值算法

public static Bitmap createBlackAndWhite(Bitmap src) {    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;    // 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); R = Color.red(pixel); G = Color.green(pixel); B = Color.blue(pixel); int gray = (int) (0.2989 * R + 0.5870 * G + 0.1140 * B); // use 128 as threshold, above -> white, below -> black if (gray > 128)      gray = 255; else     gray = 0; // set new pixel color to output bitmap bmOut.setPixel(x, y, Color.argb(A, gray, gray, gray));        }    }    return bmOut;}

但是，根据看起来不太好的东西，要获得更好的结果，您需要使用抖动算法，请参阅算法概述
-这是阈值方法。

对于256级灰度转换：

根据http://www.mathworks.de/help/toolbox/images/ref/rgb2gray.html，您可以计算每个像素的灰度值，以

gray= 0.2989 * R + 0.5870 * G + 0.1140 * B

public static Bitmap createGrayscale(Bitmap src) {    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;    // 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); R = Color.red(pixel); G = Color.green(pixel); B = Color.blue(pixel); int gray = (int) (0.2989 * R + 0.5870 * G + 0.1140 * B); // set new pixel color to output bitmap bmOut.setPixel(x, y, Color.argb(A, gray, gray, gray));        }    }    return bmOut;}

但这很慢，因为您必须分别为数百万个像素执行此操作。

具有更好的方法来实现这一点。

// pre from that answer put into method from abovepublic static Bitmap createGrayscale(Bitmap src) {    int width = src.getWidth();    int height = src.getHeight();    Bitmap bmOut = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);    Canvas canvas = new Canvas(bmOut);    ColorMatrix ma = new ColorMatrix();    ma.setSaturation(0);    Paint paint = new Paint();    paint.setColorFilter(new ColorMatrixColorFilter(ma));    canvas.drawBitmap(src, 0, 0, paint);    return bmOut;}