android 图片素描算法

1、原图片去色

int[] getGray(int[] pixels, int width, int height)
    {
        int gray[] = new int[width * height];
        for (int i = 0; i < width - 1; i++)
        {
            for (int j = 0; j < height - 1; j++)
            {
                int index = width * j + i;
                int rgba = pixels[index];
                int g = ((rgba & 0x00FF0000) >> 16) * 3 + ((rgba & 0x0000FF00) >> 8) * 6 + ((rgba & 0x000000FF)) * 1;
                gray[index] = g / 10;
            }
        }

        return gray;
    }

2、对去色灰度图取反色

public int[] getInverse(int[] gray)
    {
        int[] inverse = new int[gray.length];

        for (int i = 0, size = gray.length; i < size; i++)
        {
            inverse[i] = 255 - gray[i];
        }
        return inverse;
    }

3、对反色高斯模糊

public int[] guassBlur(int[] inverse, int width, int height)
    {
        int[] guassBlur = new int[inverse.length];

        for (int i = 0; i < width; i++)
        {
            for (int j = 0; j < height; j++)
            {
                int temp = width * (j) + (i);
                if ((i == 0) || (i == width - 1) || (j == 0) || (j == height - 1))
                {
                    guassBlur[temp] = 0;
                }
                else
                {
                    int i0 = width * (j - 1) + (i - 1);
                    int i1 = width * (j - 1) + (i);
                    int i2 = width * (j - 1) + (i + 1);
                    int i3 = width * (j) + (i - 1);
                    int i4 = width * (j) + (i);
                    int i5 = width * (j) + (i + 1);
                    int i6 = width * (j + 1) + (i - 1);
                    int i7 = width * (j + 1) + (i);
                    int i8 = width * (j + 1) + (i + 1);

                    int sum = inverse[i0] + 2 * inverse[i1] + inverse[i2] + 2 * inverse[i3] + 4 * inverse[i4] + 2 * inverse[i5] + inverse[i6] + 2 * inverse[i7] + inverse[i8];

                    sum /= 16;

                    guassBlur[temp] = sum;
                }
            }
        }
        return guassBlur;
    }

4、对取得高斯灰度值与 去色灰度值 进行颜色减淡混合

public int[] deceasecolorCompound(int[] guassBlur, int[] gray, int width, int height)
    {        
        int a, b, temp;
        float ex;
        int[] output = new int[guassBlur.length];

        for(int i=0 ; i< width ; i++)
        {
            for(int j=0 ; j)
            {
                int index = j*width + i;
                b = guassBlur[index];
                a = gray[index];
                
                temp = a+a*b/(256-b);
                ex = temp*temp*1.0f/255/255;
                temp = (int) (temp *ex);
                
                a = Math.min(temp, 255);
                
                output[index] = a;
            }
        }
        return output;
    }

5、根据混合结果灰度值生成图片

public Bitmap create(int[] pixels , int[] output,int width , int height)
    {
        for(int i=0 ,size = pixels.length ; i)
        {
            int gray = output[i];
            int pixel = (pixels[i] & 0xff000000) | (gray<<16) | (gray<< 8) | gray;//注意加上原图的 alpha通道
            
            output[i] = pixel;
        }
        
        return Bitmap.createBitmap(output, width, height, Config.ARGB_8888);
    }

6、整合

    public Bitmap createPencli(Bitmap bitmap)
    {
        int width = bitmap.getWidth();
        int height = bitmap.getHeight();
        int[] pixels = new int[width * height];
        bitmap.getPixels(pixels, 0, width, 0, 0, width, height);

        int[] gray = getGray(pixels, width, height);
        int[] inverse = getInverse(gray);

        int[] guassBlur = guassBlur(inverse, width, height);
        
        int[] output = deceasecolorCompound(guassBlur , gray , width , height);

        return create(pixels, output, width, height);
    }

 

参考文章：

http://blog.csdn.net/wsfdl/article/details/7610634

http://lzhj.me/archives/69

http://www.websbook.com/photoshop/Photoshopjzpzwxsdsmxgt_17510.html

http://blog.csdn.net/jia20003/article/details/7234741