Rotate images from any angle

the function of rotating an image from any angle is concise.

/** <Br/> * @ Param imgsource source image <br/> * @ Param CX: the rotation point is relative to the x-axis of the source image. <br/> * @ Param Cy: the rotation point is relative to the source image is taken as the vertical coordinate <br/> * @ Param Theta the angle from which the image rotates counterclockwise <br/> * @ return the rotated image <br/> */<br/> Public Image rotate (image imgsource, int CX, int cy, double theta) <br/>{< br/> If (math. ABS (theta % 360) <1) <br/> return imgsource; // return directly if the angle is very small </P> <p> int W1 = imgsource. getwidth (); // the height and width of the original image </P> <p> int H1 = imgsource. getheight (); </P> <p> int [] Srcmap = new int [W1 * H1]; </P> <p> imgsource. getrgb (srcmap, 0, W1, 0, 0, W1, H1 ); // obtain the pixel information of the original image </P> <p> int dx = Cx> W1/2? CX: W1-cx; // calculate the rotation radius </P> <p> int DY = Cy> H1/2? Cy: H1-cy; </P> <p> double DR = math. SQRT (dx * dx + dy * Dy); </P> <p> int wh2 = (INT) (2 * Dr + 1 ); // After rotation, the new image is a square with the side length + 1 to prevent array out of bounds </P> <p> int [] destmap = new int [wh2 * wh2]; // array for storing new image pixels </P> <p> double destx and desty; </P> <p> double radian = Theta * Math. PI/180; // calculate the radian value from the angle </P> <p> for (INT I = 0; I <W1; I ++) {<br/> for (Int J = 0; j <H1; j ++) {<br/> If (srcmap [J * W1 + I]> 24! = 0) {// process non-transparent Points <br/> // obtain the coordinates of the current point after rotation relative to the upper left corner of the new image <br/> destx = DR + (I-cx) * Math. cos (radian) + (J-cy) // This location does not understand <br/> * Math. sin (radian); <br/> desty = DR + (J-cy) * Math. cos (radian)-(I-cx) // This location does not understand <br/> * Math. sin (radian); <br/> // fill in pixels from the source image to the new image <br/> destmap [(INT) desty * wh2 + (INT) destx] = srcmap [J * W1 <br/> + I]; // do not understand <br/>}< br/> return image. creatergbimage (destmap, wh2, wh2, true); // returns the rotated image <br/>}

 

Another drawback is that the rotated image is a little distorted. The function marks a point that you don't understand.