android圖片特效處理之模糊效果

這篇將講到圖片特效處理的模糊效果。跟前面一樣是對像素點進行處理，算法是通用的，但耗時會更長，至於為什么，看了下面的代碼你就會明白。

算法：

一、簡單算法：將像素點周圍八個點包括自身一共九個點的RGB值分別相加后平均，作為當前像素點的RGB值，即可實現效果。

舉例：

ABC

DEF

GHI

假如當前點是E，那么會有：

E.r = (A.r + B.r + C.r + D.r + E.r + F.r + G.r + H.r + I.r) /9  // r表示的是E像素點RGB值的R值 

E.r = (A.r + B.r + C.r + D.r + E.r + F.r + G.r + H.r + I.r) / 9  // r表示的是E像素點RGB值的R值  

　　

E像素點的GB值類似。

二、采用高斯模糊：

高斯矩陣：

int[] gauss = new int[] { 1, 2, 1, 2, 4, 2, 1, 2, 1 }; 
nt[] gauss = new int[] { 1, 2, 1, 2, 4, 2, 1, 2, 1 };  

算法是：將九個點的RGB值分別與高斯矩陣中的對應項相乘的和，然后再除以一個相應的值作為當前像素點的RGB值。

 

舉例：（還是上面的九個點）
假如當前點是E，那么會有：

int delta = 16; 
E.r =( A.r * gauss[0] + B.r * gauss[1] + C.r * gauss[2] + D.r * gauss[3] + E.r * gauss[4] + F.r * gauss[5] + G.r * gauss[6] + H.r * gauss[7] + I.r * gauss[8]) / delta 

int delta = 16;  
E.r =( A.r * gauss[0] + B.r * gauss[1] + C.r * gauss[2] + D.r * gauss[3] + E.r * gauss[4] + F.r * gauss[5] + G.r * gauss[6] + H.r * gauss[7] + I.r * gauss[8]) / delta  

E像素點的GB值類似，delta的取值貌似沒有規定值，可以自己設置任意值，但要想達到效果，能設的值很少，下面圖片是值為16的效果。
處理效果：

原圖片：

兩種處理方式的代碼：

/**
     * 模糊效果
     * @param bmp
     * @return
     */ 
    private Bitmap blurImage(Bitmap bmp) 
    { 
        int width = bmp.getWidth(); 
        int height = bmp.getHeight(); 
        Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.RGB_565); 
         
        int pixColor = 0; 
         
        int newR = 0; 
        int newG = 0; 
        int newB = 0; 
         
        int newColor = 0; 
         
        int[][] colors = new int[9][3]; 
        for (int i = 1, length = width - 1; i < length; i++) 
        { 
            for (int k = 1, len = height - 1; k < len; k++) 
            { 
                for (int m = 0; m < 9; m++) 
                { 
                    int s = 0; 
                    int p = 0; 
                    switch(m) 
                    { 
                    case 0: 
                        s = i - 1; 
                        p = k - 1; 
                        break; 
                    case 1: 
                        s = i; 
                        p = k - 1; 
                        break; 
                    case 2: 
                        s = i + 1; 
                        p = k - 1; 
                        break; 
                    case 3: 
                        s = i + 1; 
                        p = k; 
                        break; 
                    case 4: 
                        s = i + 1; 
                        p = k + 1; 
                        break; 
                    case 5: 
                        s = i; 
                        p = k + 1; 
                        break; 
                    case 6: 
                        s = i - 1; 
                        p = k + 1; 
                        break; 
                    case 7: 
                        s = i - 1; 
                        p = k; 
                        break; 
                    case 8: 
                        s = i; 
                        p = k; 
                    } 
                    pixColor = bmp.getPixel(s, p); 
                    colors[m][0] = Color.red(pixColor); 
                    colors[m][1] = Color.green(pixColor); 
                    colors[m][2] = Color.blue(pixColor); 
                } 
                 
                for (int m = 0; m < 9; m++) 
                { 
                    newR += colors[m][0]; 
                    newG += colors[m][1]; 
                    newB += colors[m][2]; 
                } 
                 
                newR = (int) (newR / 9F); 
                newG = (int) (newG / 9F); 
                newB = (int) (newB / 9F); 
                 
                newR = Math.min(255, Math.max(0, newR)); 
                newG = Math.min(255, Math.max(0, newG)); 
                newB = Math.min(255, Math.max(0, newB)); 
                 
                newColor = Color.argb(255, newR, newG, newB); 
                bitmap.setPixel(i, k, newColor); 
                 
                newR = 0; 
                newG = 0; 
                newB = 0; 
            } 
        } 
         
        return bitmap; 
    } 
     
    /**
     * 柔化效果(高斯模糊)(優化后比上面快三倍)
     * @param bmp
     * @return
     */ 
    private Bitmap blurImageAmeliorate(Bitmap bmp) 
    { 
        long start = System.currentTimeMillis(); 
        // 高斯矩陣 
        int[] gauss = new int[] { 1, 2, 1, 2, 4, 2, 1, 2, 1 }; 
         
        int width = bmp.getWidth(); 
        int height = bmp.getHeight(); 
        Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.RGB_565); 
         
        int pixR = 0; 
        int pixG = 0; 
        int pixB = 0; 
         
        int pixColor = 0; 
         
        int newR = 0; 
        int newG = 0; 
        int newB = 0; 
         
        int delta = 16; // 值越小圖片會越亮，越大則越暗 
         
        int idx = 0; 
        int[] pixels = new int[width * height]; 
        bmp.getPixels(pixels, 0, width, 0, 0, width, height); 
        for (int i = 1, length = height - 1; i < length; i++) 
        { 
            for (int k = 1, len = width - 1; k < len; k++) 
            { 
                idx = 0; 
                for (int m = -1; m <= 1; m++) 
                { 
                    for (int n = -1; n <= 1; n++) 
                    { 
                        pixColor = pixels[(i + m) * width + k + n]; 
                        pixR = Color.red(pixColor); 
                        pixG = Color.green(pixColor); 
                        pixB = Color.blue(pixColor); 
                         
                        newR = newR + (int) (pixR * gauss[idx]); 
                        newG = newG + (int) (pixG * gauss[idx]); 
                        newB = newB + (int) (pixB * gauss[idx]); 
                        idx++; 
                    } 
                } 
                 
                newR /= delta; 
                newG /= delta; 
                newB /= delta; 
                 
                newR = Math.min(255, Math.max(0, newR)); 
                newG = Math.min(255, Math.max(0, newG)); 
                newB = Math.min(255, Math.max(0, newB)); 
                 
                pixels[i * width + k] = Color.argb(255, newR, newG, newB); 
                 
                newR = 0; 
                newG = 0; 
                newB = 0; 
            } 
        } 
         
        bitmap.setPixels(pixels, 0, width, 0, 0, width, height); 
        long end = System.currentTimeMillis(); 
        Log.d("may", "used time="+(end - start)); 
        return bitmap; 
    } 

/** 
     * 模糊效果 
     * @param bmp 
     * @return 
     */  
    private Bitmap blurImage(Bitmap bmp)  
    {  
        int width = bmp.getWidth();  
        int height = bmp.getHeight();  
        Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.RGB_565);  
          
        int pixColor = 0;  
          
        int newR = 0;  
        int newG = 0;  
        int newB = 0;  
          
        int newColor = 0;  
          
        int[][] colors = new int[9][3];  
        for (int i = 1, length = width - 1; i < length; i++)  
        {  
            for (int k = 1, len = height - 1; k < len; k++)  
            {  
                for (int m = 0; m < 9; m++)  
                {  
                    int s = 0;  
                    int p = 0;  
                    switch(m)  
                    {  
                    case 0:  
                        s = i - 1;  
                        p = k - 1;  
                        break;  
                    case 1:  
                        s = i;  
                        p = k - 1;  
                        break;  
                    case 2:  
                        s = i + 1;  
                        p = k - 1;  
                        break;  
                    case 3:  
                        s = i + 1;  
                        p = k;  
                        break;  
                    case 4:  
                        s = i + 1;  
                        p = k + 1;  
                        break;  
                    case 5:  
                        s = i;  
                        p = k + 1;  
                        break;  
                    case 6:  
                        s = i - 1;  
                        p = k + 1;  
                        break;  
                    case 7:  
                        s = i - 1;  
                        p = k;  
                        break;  
                    case 8:  
                        s = i;  
                        p = k;  
                    }  
                    pixColor = bmp.getPixel(s, p);  
                    colors[m][0] = Color.red(pixColor);  
                    colors[m][1] = Color.green(pixColor);  
                    colors[m][2] = Color.blue(pixColor);  
                }  
                  
                for (int m = 0; m < 9; m++)  
                {  
                    newR += colors[m][0];  
                    newG += colors[m][1];  
                    newB += colors[m][2];  
                }  
                  
                newR = (int) (newR / 9F);  
                newG = (int) (newG / 9F);  
                newB = (int) (newB / 9F);  
                  
                newR = Math.min(255, Math.max(0, newR));  
                newG = Math.min(255, Math.max(0, newG));  
                newB = Math.min(255, Math.max(0, newB));  
                  
                newColor = Color.argb(255, newR, newG, newB);  
                bitmap.setPixel(i, k, newColor);  
                  
                newR = 0;  
                newG = 0;  
                newB = 0;  
            }  
        }  
          
        return bitmap;  
    }  
      
    /** 
     * 柔化效果(高斯模糊)(優化后比上面快三倍) 
     * @param bmp 
     * @return 
     */  
    private Bitmap blurImageAmeliorate(Bitmap bmp)  
    {  
        long start = System.currentTimeMillis();  
        // 高斯矩陣  
        int[] gauss = new int[] { 1, 2, 1, 2, 4, 2, 1, 2, 1 };  
          
        int width = bmp.getWidth();  
        int height = bmp.getHeight();  
        Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.RGB_565);  
          
        int pixR = 0;  
        int pixG = 0;  
        int pixB = 0;  
          
        int pixColor = 0;  
          
        int newR = 0;  
        int newG = 0;  
        int newB = 0;  
          
        int delta = 16; // 值越小圖片會越亮，越大則越暗  
          
        int idx = 0;  
        int[] pixels = new int[width * height];  
        bmp.getPixels(pixels, 0, width, 0, 0, width, height);  
        for (int i = 1, length = height - 1; i < length; i++)  
        {  
            for (int k = 1, len = width - 1; k < len; k++)  
            {  
                idx = 0;  
                for (int m = -1; m <= 1; m++)  
                {  
                    for (int n = -1; n <= 1; n++)  
                    {  
                        pixColor = pixels[(i + m) * width + k + n];  
                        pixR = Color.red(pixColor);  
                        pixG = Color.green(pixColor);  
                        pixB = Color.blue(pixColor);  
                          
                        newR = newR + (int) (pixR * gauss[idx]);  
                        newG = newG + (int) (pixG * gauss[idx]);  
                        newB = newB + (int) (pixB * gauss[idx]);  
                        idx++;  
                    }  
                }  
                  
                newR /= delta;  
                newG /= delta;  
                newB /= delta;  
                  
                newR = Math.min(255, Math.max(0, newR));  
                newG = Math.min(255, Math.max(0, newG));  
                newB = Math.min(255, Math.max(0, newB));  
                  
                pixels[i * width + k] = Color.argb(255, newR, newG, newB);  
                  
                newR = 0;  
                newG = 0;  
                newB = 0;  
            }  
        }  
          
        bitmap.setPixels(pixels, 0, width, 0, 0, width, height);  
        long end = System.currentTimeMillis();  
        Log.d("may", "used time="+(end - start));  
        return bitmap;  
    }  

在優化后的代碼中要注意了，pixels數組不能超過規定的大小，也就是說圖片的尺寸不能太大，否則會棧內存溢出。

轉自：http://blog.csdn.net/sjf0115/article/details/7266998