Android下常用的图像处理程序(灰度化、线性灰度变化、二值化)

1、图像灰度化：

public Bitmap bitmap2Gray(Bitmap bmSrc) {
		// 得到图片的长和宽
		int width = bmSrc.getWidth();
		int height = bmSrc.getHeight();
		// 创建目标灰度图像
		Bitmap bmpGray = null;
		bmpGray = Bitmap.createBitmap(width, height, Bitmap.Config.RGB_565);
		// 创建画布
		Canvas c = new Canvas(bmpGray);
		Paint paint = new Paint();
		ColorMatrix cm = new ColorMatrix();
		cm.setSaturation(0);
		ColorMatrixColorFilter f = new ColorMatrixColorFilter(cm);
		paint.setColorFilter(f);
		c.drawBitmap(bmSrc, 0, 0, paint);
		return bmpGray;
	}

2、对图像进行线性灰度变化

public Bitmap lineGrey(Bitmap image) 
	{
		//得到图像的宽度和长度
		int width = image.getWidth();
		int height = image.getHeight();
		//创建线性拉升灰度图像
		Bitmap linegray = null;
		linegray = image.copy(Config.ARGB_8888, true);
		//依次循环对图像的像素进行处理
		for (int i = 0; i < width; i++) {
			for (int j = 0; j < height; j++) {
				//得到每点的像素值
				int col = image.getPixel(i, j);
				int alpha = col & 0xFF000000;
				int red = (col & 0x00FF0000) >> 16;
				int green = (col & 0x0000FF00) >> 8;
				int blue = (col & 0x000000FF);
				// 增加了图像的亮度
				red = (int) (1.1 * red + 30);
				green = (int) (1.1 * green + 30);
				blue = (int) (1.1 * blue + 30);
				//对图像像素越界进行处理
				if (red >= 255) 
				{
					red = 255;
				}

				if (green >= 255) {
					green = 255;
				}

				if (blue >= 255) {
					blue = 255;
				}
				// 新的ARGB
				int newColor = alpha | (red << 16) | (green << 8) | blue;
				//设置新图像的RGB值
				linegray.setPixel(i, j, newColor);
			}
		}
		return linegray;
	}

3、对图像进行二值化

// 该函数实现对图像进行二值化处理
	public Bitmap gray2Binary(Bitmap graymap) {
		//得到图形的宽度和长度
		int width = graymap.getWidth();
		int height = graymap.getHeight();
		//创建二值化图像
		Bitmap binarymap = null;
		binarymap = graymap.copy(Config.ARGB_8888, true);
		//依次循环，对图像的像素进行处理
		for (int i = 0; i < width; i++) {
			for (int j = 0; j < height; j++) {
				//得到当前像素的值
				int col = binarymap.getPixel(i, j);
				//得到alpha通道的值
				int alpha = col & 0xFF000000;
				//得到图像的像素RGB的值
				int red = (col & 0x00FF0000) >> 16;
				int green = (col & 0x0000FF00) >> 8;
				int blue = (col & 0x000000FF);
				// 用公式X = 0.3×R+0.59×G+0.11×B计算出X代替原来的RGB
				int gray = (int) ((float) red * 0.3 + (float) green * 0.59 + (float) blue * 0.11);
				//对图像进行二值化处理
				if (gray <= 95) {
					gray = 0;
				} else {
					gray = 255;
				}
				// 新的ARGB
				int newColor = alpha | (gray << 16) | (gray << 8) | gray;
				//设置新图像的当前像素值
				binarymap.setPixel(i, j, newColor);
			}
		}
		return binarymap;
	}