【Android图像处理】图像处理之-幻觉滤镜

所谓的幻觉，其实就是将在原有图片的基础上生成几个幻象，看上去就像自己出现了幻觉一样。

具体的代码如下：

	//幻觉
	public static Bitmap Illusion(Bitmap bitmap){
		int w = bitmap.getWidth();
		int h = bitmap.getHeight();

		Bitmap result = Bitmap.createBitmap(w, h, Bitmap.Config.RGB_565);

		int r, g, b, color;
		int r1, g1, b1, color1;

		int[] oldPx = new int[w * h];
		int[] newPx = new int[w * h];

		bitmap.getPixels(oldPx, 0, w, 0, 0, w, h);

		for(int x = 0 ; x < (w - 1) ; x++){
			for(int y = 0 ; y < (h - 1) ; y++){
				//得到当前点的r,g,b值
				color = oldPx[x * h + y];
				r = Color.red(color);
				g = Color.green(color);
				b = Color.blue(color);

				double _scale = Math.sqrt(w*w + h*h) / 2 ;
				double _offset = (int)(_scale / 2) ;
				double cx = (x - w / 2.0) / _scale ;
				double cy = (y - h / 2.0) / _scale ;
				double _amount = Math.PI / 3 ;
				double angle = Math.floor ( Math.atan2(cy,cx) / 2.0 / _amount) * 2.0 * _amount + _amount;
				double radius =  Math.sqrt(cx*cx + cy*cy) ;
				int xx = (int)(x - _offset *  Math.cos(angle)) ;
				int yy = (int)(y - _offset *  Math.sin(angle)) ;

				xx = Function.FClamp(xx, 0, (int)(w-1));
				yy = Function.FClamp(yy, 0, (int)(h-1));

				//得到当前点的r,g,b值
				color1 = oldPx[xx * h + yy];
				r1 = Color.red(color1);
				g1 = Color.green(color1);
				b1 = Color.blue(color1);

				r = Function.FClamp0255 (r + radius * (r1 - r)) ;
				g = Function.FClamp0255 (g + radius * (g1 - g)) ;
				b = Function.FClamp0255 (b + radius * (b1 - b)) ;

				newPx[x * h + y] = Color.rgb(r, g, b);
			}
		}
		result.setPixels(newPx, 0, w, 0, 0, w, h);
		return result;
	}

public class Function {

	public static int FClamp(final int t, final int tLow, final int tHigh)
	{
		if (t < tHigh)
		{
			return ((t > tLow) ? t : tLow) ;
		}
		return tHigh ;
	}

	public static double FClampDouble(final double t, final double tLow, final double tHigh)
	{
		if (t < tHigh)
		{
			return ((t > tLow) ? t : tLow) ;
		}
		return tHigh ;
	}

	public static int FClamp0255(final double d)
	{
		return (int)(FClampDouble(d, 0.0, 255.0) + 0.5) ;
	}
}

                     效果图                                                          原图

右边的原图是经过压缩后的图，在使用这个算法的时候，最好采用压缩算法，将图片截取成宽高相等的图片，否则达不到预期的效果。