[C #] three-dimensional Verification Code (3 dcaptcha)

Source:

3 dcaptchaHttp://www-personal.umich.edu /~ Mressl/3 dcaptcha/

Http://code.google.com/p/3dcaptcha/

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This example is complete.ProgramTranslation, no additional processing.

C #AlgorithmImplementation

/*** Dcaptcha for. Net ** http://www-personal.umich.edu /~ Mressl/3 dcaptcha/(PHP) * http://code.google.com/p/3dcaptcha/ (PHP) ** translate: aimeast * blog: http://www.cnblogs.com/Aimeast/ */using system; using system. drawing; namespace CAPTCHA {public static class CAPTCHA {Private Static double [] addvector (double [] A, double [] B) {return New Double [] {A [0] + B [0], a [1] + B [1], a [2] + B [2]};} private Static double [] scalarproduct (double [] vector, double scalar) {return New Double [] {vector [0] * scalar, vector [1] * scalar, vector [2] * scalar};} Private Static double dotproduct (double [] A, double [] B) {return a [0] * B [0] + A [1] * B [1] + A [2] * B [2];} private Static double norm (double [] vector) {return math. SQRT (dotproduct (vector, vector);} Private Static double [] normalize (double [] vector) {return scalarproduct (vector, 1.0/norm (vector ));} // http://en.wikipedia.org/wiki/Cross_product Private Static double [] crossproduct (double [] A, double [] B) {return New Double [] {(A [1] * B [2]-A [2] * B [1]), (A [2] * B [0]-A [0] * B [2]), (A [0] * B [1]-A [1] * B [0])};} Private Static double [] vectorproductindexed (double [] V, double [] M, int I) {return New Double [] {v [I + 0] * m [0] + V [I + 1] * m [4] + V [I + 2] * m [8] + V [I + 3] * m [12], V [I + 0] * m [1] + V [I + 1] * m [5] + V [I + 2] * m [9] + V [I + 3] * m [13], V [I + 0] * m [2] + V [I + 1] * m [6] + V [I + 2] * m [10] + V [I + 3] * m [14], V [I + 0] * m [3] + V [I + 1] * m [7] + V [I + 2] * m [11] + V [I + 3] * m [15]};} private Static double [] vectorproduct (double [] V, double [] m) {return vectorproductindexed (v, M, 0 );} private Static double [] matrixproduct (double [] A, double [] B) {double [] O1 = vectorproductindexed (a, B, 0 ); double [] O2 = vectorproductindexed (a, B, 4); double [] O3 = vectorproductindexed (a, B, 8); double [] O4 = vectorproductindexed (A, B, 12); return New Double [] {O1 [0], O1 [1], O1 [2], O1 [3], O2 [0], O2 [1], o2 [2], O2 [3], O3 [0], O3 [1], O3 [2], O3 [3], O4 [0], O4 [1], o4 [2], O4 [3]};} // http://graphics.idav.ucdavis.edu/education/GraphicsNotes/Camera-Transform/Camera-Transform.html Private Static double [] cameratransform (double [] C, double []) {double [] W = normalize (addvector (C, scalarproduct (A,-1); double [] Y = new double [] {0, 1, 0 }; double [] U = normalize (crossproduct (Y, W); double [] V = crossproduct (W, U); double [] T = scalarproduct (C,-1 ); return New Double [] {u [0], V [0], W [0], 0, U [1], V [1], W [1], 0, U [2], V [2], W [2], 0, dotproduct (u, T), dotproduct (v, T), dotproduct (W, T ), 1 };}// http://graphics.idav.ucdavis.edu/education/GraphicsNotes/Viewing-Transformation/Viewing-Transformation.html Private Static double [] viewingtransform (double FOV, double N, double F) {FOV * = (math. PI/180); double cot = 1.0/math. tan (FOV/2); return New Double [] {cot, 0, 0, 0, Cot, 0, 0, 0, 0, (F + N)/(F-N ), -1, 0, 0, 2 * f * n/(F-N), 0 };} public static image generate (string captchatext) {random RND = new random (); // 3 dcha parameters int fontsize = 24; font = new font ("Arial", fontsize); sizef; using (Graphics G = graphics. fromimage (New Bitmap (1, 1) {sizef = G. measurestring (captchatext, Font, 0, stringformat. genericdefault);} int image2d_x = (INT) sizef. width; int image2d_y = (INT) (fontsize * 1.3); double bevel = 4; // create 2D image bitmap image2d = new Bitmap (image2d_x, image2d_y); color black = color. black; color white = color. white; // paint 2D image using (Graphics G = graphics. fromimage (image2d) {G. clear (black); G. drawstring (captchatext, Font, brushes. white, 0, 0);} // calculate projection matrix double [] T = cameratransform (New Double [] {RND. next (-90,90),-200, RND. next (150,250)}, new double [] {0, 0, 0}); t = matrixproduct (T, viewingtransform (60,300,300 0 )); // calculate coordinates double [] [] coord = new double [image2d_x * image2d_y] []; int COUNT = 0; For (INT y = 0; y <image2d_y; Y + = 2) {for (INT x = 0; x <image2d_x; X ++) {// calculate X1, Y1, X2, y2 int XC = x-image2d_x/2; int ZC = Y-image2d_y/2; double YC =-(double) (image2d. getpixel (x, y ). toargb () & 0xff)/256 * bevel; double [] xyz = new double [] {XC, YC, ZC, 1}; XYZ = vectorproduct (xyz, t ); coord [count] = xyz; count ++ ;}// create 3D image int image3d_x = 256; // $ image3d_y = $ image3d_x/1.618; int image3d_y = image3d_x * 9/16; bitmap image3d = new Bitmap (image3d_x, image3d_y); color fgcolor = color. white; color bgcolor = color. black; using (Graphics G = graphics. fromimage (image3d) {G. clear (bgcolor); Count = 0; double scale = 1.75-(double) image2d_x/400; For (INT y = 0; y <image2d_y; y + = 2) {for (INT x = 0; x <image2d_x; X ++) {If (x> 0) {double X0 = coord [count-1] [0] * scale + image3d_x/2; double Y0 = coord [count-1] [1] * scale + image3d_y/2; double X1 = coord [count] [0] * scale + image3d_x/2; double Y1 = coord [count] [1] * scale + image3d_y/2; G. drawline (new pen (fgcolor), (float) x0, (float) y0, (float) x1, (float) Y1) ;}count ++ ;}}} return image3d ;}}}

Usage

 
This. backgroundimage = CAPTCHA. Generate ("Code ");
 

Effect