Image processing algorithm (7)

VII. Diffusion
Move the color values of random points within the range of xoffset and yoffset to the current position for display. Another way is to move the current vertex to another position for display. P1 + Stride * Yin + Xin *   3 is the offset calculation method. 1 Public   Static   Bool Diffuse (Bitmap B, Int Xoffset, Int Yoffset, Int Step)
2 {
3 Bitmapdata bmdata = B. lockbits ( New Rectangle ( 0 , 0 , B. Width, B. Height ),
4 Imagelockmode. readwrite, pixelformat. format24bpprgb );
5 Int Stride = Bmdata. stride;
6 System. intptr scan0 = Bmdata. scan0;
7 Unsafe
8 {
9 Byte   * P = ( Byte   * )( Void   * ) Scan0;
10 Byte   * P1 = P;
11 Int Noffset = Stride - B. Width * 3 ;
12 Random Rad =   New Random ();
13 For ( Int Y = 0 ; Y < B. height; ++ Y)
14 {
15 For ( Int X = 0 ; X < B. width; ++ X)
16 {
17 If (Y % Step =   0   && X % Step =   0 )
18 {
19 Int Xin = Rad. Next ( 2   * Xoffset) - Xoffset + X;
20 Int Yin = Rad. Next ( 2   * Yoffset) - Yoffset + Y;
21 If (Xin <   1 ) Xin =   0 ;
22 Else   If (Xin > B. Width -   1 ) Xin = B. Width -   1 ;
23 If (Yin <   1 ) Yin =   0 ;
24 Else   If (Yin > B. Height -   1 ) Yin = B. Height -   1 ;
25 Byte   * Ptemp = P1 + Stride * Yin + Xin *   3 ;
26 P [ 0 ] = Ptemp [ 0 ];
27 P [ 1 ] = Ptemp [ 1 ];
28 P [ 2 ] = Ptemp [ 2 ];
29 }
30 P + =   3 ;
31 }
32 P + = Noffset;
33 }
34 }
35 B. unlockbits (bmdata );
36 Return   True ;
37 }