android图片特效处理之模糊效果

Posted 2020-09-11 brave-sailor

这篇将讲到图片特效处理的模糊效果。跟前面一样是对像素点进行处理，算法是通用的，但耗时会更长，至于为什么，看了下面的代码你就会明白。

算法：

一、简单算法：将像素点周围八个点包括自身一共九个点的RGB值分别相加后平均，作为当前像素点的RGB值，即可实现效果。

举例：

ABC

DEF

GHI

假如当前点是E，那么会有：

[java] view plaincopy

1. 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像素点RGB值的R值 

[java] view plain copy

1. 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像素点RGB值的R值  

E像素点的GB值类似。

二、采用高斯模糊：

高斯矩阵：

[java] view plaincopy

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

[java] view plain copy

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

算法是：将九个点的RGB值分别与高斯矩阵中的对应项相乘的和，然后再除以一个相应的值作为当前像素点的RGB值。

举例：（还是上面的九个点）
假如当前点是E，那么会有：

[java] view plaincopy

1. int delta = 16; 
2. 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 

[java] view plain copy

1. int delta = 16;  
2. 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像素点的GB值类似，delta的取值貌似没有规定值，可以自己设置任意值，但要想达到效果，能设的值很少，下面图片是值为16的效果。
处理效果：

原图片：

处理后：

两种处理方式的代码：

[java] view plaincopy

1. /**
2.      * 模糊效果
3.      * @param bmp
4.      * @return
5.      */ 
6.     private Bitmap blurImage(Bitmap bmp) 
7.     { 
8.         int width = bmp.getWidth(); 
9.         int height = bmp.getHeight(); 
10.         Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.RGB_565); 
11.          
12.         int pixColor = 0; 
13.          
14.         int newR = 0; 
15.         int newG = 0; 
16.         int newB = 0; 
17.          
18.         int newColor = 0; 
19.          
20.         int[][] colors = new int[9][3]; 
21.         for (int i = 1, length = width - 1; i < length; i++) 
22.         { 
23.             for (int k = 1, len = height - 1; k < len; k++) 
24.             { 
25.                 for (int m = 0; m < 9; m++) 
26.                 { 
27.                     int s = 0; 
28.                     int p = 0; 
29.                     switch(m) 
30.                     { 
31.                     case 0: 
32.                         s = i - 1; 
33.                         p = k - 1; 
34.                         break; 
35.                     case 1: 
36.                         s = i; 
37.                         p = k - 1; 
38.                         break; 
39.                     case 2: 
40.                         s = i + 1; 
41.                         p = k - 1; 
42.                         break; 
43.                     case 3: 
44.                         s = i + 1; 
45.                         p = k; 
46.                         break; 
47.                     case 4: 
48.                         s = i + 1; 
49.                         p = k + 1; 
50.                         break; 
51.                     case 5: 
52.                         s = i; 
53.                         p = k + 1; 
54.                         break; 
55.                     case 6: 
56.                         s = i - 1; 
57.                         p = k + 1; 
58.                         break; 
59.                     case 7: 
60.                         s = i - 1; 
61.                         p = k; 
62.                         break; 
63.                     case 8: 
64.                         s = i; 
65.                         p = k; 
66.                     } 
67.                     pixColor = bmp.getPixel(s, p); 
68.                     colors[m][0] = Color.red(pixColor); 
69.                     colors[m][1] = Color.green(pixColor); 
70.                     colors[m][2] = Color.blue(pixColor); 
71.                 } 
72.                  
73.                 for (int m = 0; m < 9; m++) 
74.                 { 
75.                     newR += colors[m][0]; 
76.                     newG += colors[m][1]; 
77.                     newB += colors[m][2]; 
78.                 } 
79.                  
80.                 newR = (int) (newR / 9F); 
81.                 newG = (int) (newG / 9F); 
82.                 newB = (int) (newB / 9F); 
83.                  
84.                 newR = Math.min(255, Math.max(0, newR)); 
85.                 newG = Math.min(255, Math.max(0, newG)); 
86.                 newB = Math.min(255, Math.max(0, newB)); 
87.                  
88.                 newColor = Color.argb(255, newR, newG, newB); 
89.                 bitmap.setPixel(i, k, newColor); 
90.                  
91.                 newR = 0; 
92.                 newG = 0; 
93.                 newB = 0; 
94.             } 
95.         } 
96.          
97.         return bitmap; 
98.     } 
99.      
100.     /**
101.      * 柔化效果(高斯模糊)(优化后比上面快三倍)
102.      * @param bmp
103.      * @return
104.      */ 
105.     private Bitmap blurImageAmeliorate(Bitmap bmp) 
106.     { 
107.         long start = System.currentTimeMillis(); 
108.         // 高斯矩阵 
109.         int[] gauss = new int[] { 1, 2, 1, 2, 4, 2, 1, 2, 1 }; 
110.          
111.         int width = bmp.getWidth(); 
112.         int height = bmp.getHeight(); 
113.         Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.RGB_565); 
114.          
115.         int pixR = 0; 
116.         int pixG = 0; 
117.         int pixB = 0; 
118.          
119.         int pixColor = 0; 
120.          
121.         int newR = 0; 
122.         int newG = 0; 
123.         int newB = 0; 
124.          
125.         int delta = 16; // 值越小图片会越亮，越大则越暗 
126.          
127.         int idx = 0; 
128.         int[] pixels = new int[width * height]; 
129.         bmp.getPixels(pixels, 0, width, 0, 0, width, height); 
130.         for (int i = 1, length = height - 1; i < length; i++) 
131.         { 
132.             for (int k = 1, len = width - 1; k < len; k++) 
133.             { 
134.                 idx = 0; 
135.                 for (int m = -1; m <= 1; m++) 
136.                 { 
137.                     for (int n = -1; n <= 1; n++) 
138.                     { 
139.                         pixColor = pixels[(i + m) * width + k + n]; 
140.                         pixR = Color.red(pixColor); 
141.                         pixG = Color.green(pixColor); 
142.                         pixB = Color.blue(pixColor); 
143.                          
144.                         newR = newR + (int) (pixR * gauss[idx]); 
145.                         newG = newG + (int) (pixG * gauss[idx]); 
146.                         newB = newB + (int) (pixB * gauss[idx]); 
147.                         idx++; 
148.                     } 
149.                 } 
150.                  
151.                 newR /= delta; 
152.                 newG /= delta; 
153.                 newB /= delta; 
154.                  
155.                 newR = Math.min(255, Math.max(0, newR)); 
156.                 newG = Math.min(255, Math.max(0, newG)); 
157.                 newB = Math.min(255, Math.max(0, newB)); 
158.                  
159.                 pixels[i * width + k] = Color.argb(255, newR, newG, newB); 
160.                  
161.                 newR = 0; 
162.                 newG = 0; 
163.                 newB = 0; 
164.             } 
165.         } 
166.          
167.         bitmap.setPixels(pixels, 0, width, 0, 0, width, height); 
168.         long end = System.currentTimeMillis(); 
169.         Log.d("may", "used time="+(end - start)); 
170.         return bitmap; 
171.     } 

[java] view plain copy

1. /** 
2.      * 模糊效果 
3.      * @param bmp 
4.      * @return 
5.      */  
6.     private Bitmap blurImage(Bitmap bmp)  
7.     {  
8.         int width = bmp.getWidth();  
9.         int height = bmp.getHeight();  
10.         Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.RGB_565);  
11.           
12.         int pixColor = 0;  
13.           
14.         int newR = 0;  
15.         int newG = 0;  
16.         int newB = 0;  
17.           
18.         int newColor = 0;  
19.           
20.         int[][] colors = new int[9][3];  
21.         for (int i = 1, length = width - 1; i < length; i++)  
22.         {  
23.             for (int k = 1, len = height - 1; k < len; k++)  
24.             {  
25.                 for (int m = 0; m < 9; m++)  
26.                 {  
27.                     int s = 0;  
28.                     int p = 0;  
29.                     switch(m)  
30.                     {  
31.                     case 0:  
32.                         s = i - 1;  
33.                         p = k - 1;  
34.                         break;  
35.                     case 1:  
36.                         s = i;  
37.                         p = k - 1;  
38.                         break;  
39.                     case 2:  
40.                         s = i + 1;  
41.                         p = k - 1;  
42.                         break;  
43.                     case 3:  
44.                         s = i + 1;  
45.                         p = k;  
46.                         break;  
47.                     case 4:  
48.                         s = i + 1;  
49.                         p = k + 1;  
50.                         break;  
51.                     case 5:  
52.                         s = i;  
53.                         p = k + 1;  
54.                         break;  
55.                     case 6:  
56.                         s = i - 1;  
57.                         p = k + 1;  
58.                         break;  
59.                     case 7:  
60.                         s = i - 1;  
61.                         p = k;  
62.                         break;  
63.                     case 8:  
64.                         s = i;  
65.                         p = k;  
66.                     }  
67.                     pixColor = bmp.getPixel(s, p);  
68.                     colors[m][0] = Color.red(pixColor);  
69.                     colors[m][1] = Color.green(pixColor);  
70.                     colors[m][2] = Color.blue(pixColor);  
71.                 }  
72.                   
73.                 for (int m = 0; m < 9; m++)  
74.                 {  
75.                     newR += colors[m][0];  
76.                     newG += colors[m][1];  
77.                     newB += colors[m][2];  
78.                 }  
79.                   
80.                 newR = (int) (newR / 9F);  
81.                 newG = (int) (newG / 9F);  
82.                 newB = (int) (newB / 9F);  
83.                   
84.                 newR = Math.min(255, Math.max(0, newR));  
85.                 newG = Math.min(255, Math.max(0, newG));  
86.                 newB = Math.min(255, Math.max(0, newB));  
87.                   
88.                 newColor = Color.argb(255, newR, newG, newB);  
89.                 bitmap.setPixel(i, k, newColor);  
90.                   
91.                 newR = 0;  
92.                 newG = 0;  
93.                 newB = 0;  
94.             }  
95.         }  
96.           
97.         return bitmap;  
98.     }  
99.       
100.     /** 
101.      * 柔化效果(高斯模糊)(优化后比上面快三倍) 
102.      * @param bmp 
103.      * @return 
104.      */  
105.     private Bitmap blurImageAmeliorate(Bitmap bmp)  
106.     {  
107.         long start = System.currentTimeMillis();  
108.         // 高斯矩阵  
109.         int[] gauss = new int[] { 1, 2, 1, 2, 4, 2, 1, 2, 1 };  
110.           
111.         int width = bmp.getWidth();  
112.         int height = bmp.getHeight();  
113.         Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.RGB_565);  
114.           
115.         int pixR = 0;  
116.         int pixG = 0;  
117.         int pixB = 0;  
118.           
119.         int pixColor = 0;  
120.           
121.         int newR = 0;  
122.         int newG = 0;  
123.         int newB = 0;  
124.           
125.         int delta = 16; // 值越小图片会越亮，越大则越暗  
126.           
127.         int idx = 0;  
128.         int[] pixels = new int[width * height];  
129.         bmp.getPixels(pixels, 0, width, 0, 0, width, height);  
130.         for (int i = 1, length = height - 1; i < length; i++)  
131.         {  
132.             for (int k = 1, len = width - 1; k < len; k++)  
133.             {  
134.                 idx = 0;  
135.                 for (int m = -1; m <= 1; m++)  
136.                 {  
137.                     for (int n = -1; n <= 1; n++)  
138.                     {  
139.                         pixColor = pixels[(i + m) * width + k + n];  
140.                         pixR = Color.red(pixColor);  
141.                         pixG = Color.green(pixColor);  
142.                         pixB = Color.blue(pixColor);  
143.                           
144.                         newR = newR + (int) (pixR * gauss[idx]);  
145.                         newG = newG + (int) (pixG * gauss[idx]);  
146.                         newB = newB + (int) (pixB * gauss[idx]);  
147.                         idx++;  
148.                     }  
149.                 }  
150.                   
151.                 newR /= delta;  
152.                 newG /= delta;  
153.                 newB /= delta;  
154.                   
155.                 newR = Math.min(255, Math.max(0, newR));  
156.                 newG = Math.min(255, Math.max(0, newG));  
157.                 newB = Math.min(255, Math.max(0, newB));  
158.                   
159.                 pixels[i * width + k] = Color.argb(255, newR, newG, newB);  
160.                   
161.                 newR = 0;  
162.                 newG = 0;  
163.                 newB = 0;  
164.             }  
165.         }  
166.           
167.         bitmap.setPixels(pixels, 0, width, 0, 0, width, height);  
168.         long end = System.currentTimeMillis();  
169.         Log.d("may", "used time="+(end - start));  
170.         return bitmap;  
171.     }