GLSL实现Image Filter

约定不等于承诺〃 2022-08-05 15:06 146阅读 0赞

[http://blog.csdn.net/a3070173/archive/2008/11/27/3390477.aspx][http_blog.csdn.net_a3070173_archive_2008_11_27_3390477.aspx]

1.  图像过滤无论是在作图工具还是特效的实现上都时有运用,这里发一些通常会使用到的图像
2.  过滤着色器供有需要的朋友参考.
3.  备注:这里列出的都是片元着色器,顶点着色器都是一样地简单变换顶点和传递纹理坐标.
4.  
5.  高斯过滤 - 常用于进行图像模糊
6.  横向过滤:
7.  const int g\_iWeightNumber = 17;
8.                                      
9.  uniform sampler2D g\_FilterTexture;  // 被过滤纹理 
10. uniform float g\_aryWeight\[g\_iWeightNumber\]; // Blur权重数组 
11. uniform vec2 g\_aryVerticalOffset\[g\_iWeightNumber\];  // 横向Blur偏移数组 
12. 
13. void main()
14. \{
15.     vec4 vec4Sum = vec4(0.0);
16.     for(int i = 0; i < g\_iWeightNumber; ++i)
17.     \{
18.         vec4Sum += texture2D(g\_FilterTexture, gl\_TexCoord\[0\].st + g\_aryVerticalOffset\[i\])\*g\_aryWeight\[i\];
19.     \}
20.         
21.     gl\_FragColor = vec4Sum;
22. \}
23. 纵向过滤:
24. const int g\_iWeightNumber = 17;
25.                                     
26. uniform sampler2D g\_FilterTexture;  // 被过滤纹理 
27. uniform float g\_aryWeight\[g\_iWeightNumber\]; // Blur权重数组 
28. uniform vec2 g\_aryHorizontalOffset\[g\_iWeightNumber\];    // 横向Blur偏移数组 
29. 
30. void main()
31. \{
32.     vec4 vec4Sum = vec4(0.0);
33.     for(int i = 0; i < g\_iWeightNumber; ++i)
34.     \{
35.         vec4Sum += texture2D(g\_FilterTexture, gl\_TexCoord\[0\].st + g\_aryHorizontalOffset\[i\])\*g\_aryWeight\[i\];
36.     \}
37.         
38.     gl\_FragColor = vec4Sum;
39. \}
40. 
41. Mean过滤 - 用于纹理抗锯齿
42. // Mean kernel 
43. // 1 1 1 
44. // 1 1 1 
45. // 1 1 1     
46. const int g\_iWeightNumber = 9;
47.                                     
48. uniform sampler2D g\_FilterTexture;  // 被过滤纹理 
49. uniform float g\_aryWeight\[g\_iWeightNumber\]; // Blur权重数组 
50. uniform vec2 g\_aryOffset\[g\_iWeightNumber\];  // 横向Blur偏移数组 
51. 
52. void main()
53. \{
54.     vec4 vec4Sum = vec4(0.0);
55.     if (gl\_TexCoord\[0\].s < 0.495)
56.     \{
57.         for(int i = 0; i < g\_iWeightNumber; ++i)
58.         \{
59.             vec4Sum += texture2D(g\_FilterTexture, gl\_TexCoord\[0\].st + g\_aryOffset\[i\])\*g\_aryWeight\[i\];
60.         \}
61.     \}
62.     else if (gl\_TexCoord\[0\].s > 0.505)
63.     \{
64.         vec4Sum = texture2D(g\_FilterTexture, gl\_TexCoord\[0\].st);
65.     \}
66.     else
67.     \{
68.         vec4Sum = vec4(1.0, 0.0, 0.0, 1.0);
69.     \}
70. 
71.     gl\_FragColor = vec4Sum;
72. \}
73. 
74. Laplacian过滤 - 用于突显图像轮廓
75. // Edge detection kernel (Laplacian filter). 
76. // 0  -1 0 
77. // -1  4 -1 
78. // 0  -1 0       
79. const int g\_iWeightNumber = 9;
80.                                     
81. uniform sampler2D g\_FilterTexture;  // 被过滤纹理 
82. uniform float g\_aryWeight\[g\_iWeightNumber\]; // Blur权重数组 
83. uniform vec2 g\_aryOffset\[g\_iWeightNumber\];  // 横向Blur偏移数组 
84. 
85. void main()
86. \{
87.     vec4 vec4Sum = vec4(0.0);
88.     if (gl\_TexCoord\[0\].s < 0.495)
89.     \{
90.         for(int i = 0; i < g\_iWeightNumber; ++i)
91.         \{
92.             vec4Sum += texture2D(g\_FilterTexture, gl\_TexCoord\[0\].st + g\_aryOffset\[i\])\*g\_aryWeight\[i\];
93.         \}
94.         vec4 vec4BaseColor = texture2D(g\_FilterTexture, gl\_TexCoord\[0\].st);
95.         vec4Sum += vec4BaseColor\*0.1;
96.     \}
97.     else if (gl\_TexCoord\[0\].s > 0.505)
98.     \{
99.         vec4Sum = texture2D(g\_FilterTexture, gl\_TexCoord\[0\].st);
100.     \}
101.     else
102.     \{
103.         vec4Sum = vec4(1.0, 0.0, 0.0, 1.0);
104.     \}
105. 
106.     gl\_FragColor = vec4Sum;
107. \}
108. 
109. Emboss过滤 - used to simulate the relief of an image
110. // Emboss filter 
111. // 2   0  0 
112. // 0  -1  0 
113. // 0   0  -1         
114. const int g\_iWeightNumber = 9;
115.                                     
116. uniform sampler2D g\_FilterTexture;  // 被过滤纹理 
117. uniform float g\_aryWeight\[g\_iWeightNumber\]; // Blur权重数组 
118. uniform vec2 g\_aryOffset\[g\_iWeightNumber\];  // 横向Blur偏移数组 
119. 
120. void main()
121. \{
122.     vec4 vec4Sum = vec4(0.0);
123.     if (gl\_TexCoord\[0\].s < 0.495)
124.     \{
125.         for(int i = 0; i < g\_iWeightNumber; ++i)
126.         \{
127.             vec4Sum += texture2D(g\_FilterTexture, gl\_TexCoord\[0\].st + g\_aryOffset\[i\])\*g\_aryWeight\[i\];
128.         \}
129.         vec4Sum += 0.5;
130.     \}
131.     else if (gl\_TexCoord\[0\].s > 0.505)
132.     \{
133.         vec4Sum = texture2D(g\_FilterTexture, gl\_TexCoord\[0\].st);
134.     \}
135.     else
136.     \{
137.         vec4Sum = vec4(1.0, 0.0, 0.0, 1.0);
138.     \}
139. 
140.     gl\_FragColor = vec4Sum;
141. \}
142. 
143. Sharpness过滤 - 突显图像的细节
144. // Sharpness filter 
145. // -1  -1  -1 
146. // -1   9  -1 
147. // -1  -1  -1        
148. const int g\_iWeightNumber = 9;
149.                                     
150. uniform sampler2D g\_FilterTexture;  // 被过滤纹理 
151. uniform float g\_aryWeight\[g\_iWeightNumber\]; // Blur权重数组 
152. uniform vec2 g\_aryOffset\[g\_iWeightNumber\];  // 横向Blur偏移数组 
153. 
154. void main()
155. \{
156.     vec4 vec4Sum = vec4(0.0);
157.     if (gl\_TexCoord\[0\].s < 0.495)
158.     \{
159.         for(int i = 0; i < g\_iWeightNumber; ++i)
160.         \{
161.             vec4Sum += texture2D(g\_FilterTexture, gl\_TexCoord\[0\].st + g\_aryOffset\[i\])\*g\_aryWeight\[i\];
162.         \}
163.     \}
164.     else if (gl\_TexCoord\[0\].s > 0.505)
165.     \{
166.         vec4Sum = texture2D(g\_FilterTexture, gl\_TexCoord\[0\].st);
167.     \}
168.     else
169.     \{
170.         vec4Sum = vec4(1.0, 0.0, 0.0, 1.0);
171.     \}
172. 
173.     gl\_FragColor = vec4Sum;
174. \}
175. 
176. Demo效果截图:
177. ![1.JPG][]
178. 
179. ![2.JPG][]
180. ![3.JPG][]
181. ![4.JPG][]
182. ![5.JPG][]
183. exe文件:[http://www.fileupyours.com/view/219112/GLSL/Image%20Filter%20Demo.rar][http_www.fileupyours.com_view_219112_GLSL_Image_20Filter_20Demo.rar]

[http_blog.csdn.net_a3070173_archive_2008_11_27_3390477.aspx]: http://blog.csdn.net/a3070173/archive/2008/11/27/3390477.aspx
[1.JPG]: /images/20220805/77aac509c54c4f549c9aaae399340287.png
[2.JPG]: /images/20220805/0ef3d4d939b6465e9b7acb1bc611f65c.png
[3.JPG]: /images/20220805/7da199a0982e44288bec59b4ba938ae4.png
[4.JPG]: /images/20220805/9338777d353545858e82044b2ef872ca.png
[5.JPG]: /images/20220805/023b609a4d0f4a97a361d5b8cc8e5afb.png
[http_www.fileupyours.com_view_219112_GLSL_Image_20Filter_20Demo.rar]: http://www.fileupyours.com/view/219112/GLSL/Image%20Filter%20Demo.rar