问Java:将图像旋转90度

EN

 /**
* intialize a picture by giving an image matrix
* @param imageMatrix two dimansionar RGBColor array
*/
public Picture(RGBColor imageMatrix[][]){
    this.width = imageMatrix.length;
    this.height = imageMatrix[0].length;
    this.imageMatrix = imageMatrix;
}

/**
 * turns this picture 90 degrees to the right
 *
 */
public void rot90DegRight(){
    int w = imageMatrix.length;
    int h = imageMatrix[0].length;
    RGBColor[][] rotatedMatrix = new RGBColor[h][w];
    for (int i = 0; i<h; i++){
        for(int j = 0; j<w; j++){
            rotatedMatrix[i][j] = imageMatrix[w-j-1][i];
        }
    }

}

@Test(timeout=1000)
public void testRot90DegRight(){
    RGBColor[][] imageMatrix = new RGBColor[100][100];
    for (int w=0; w<100; w++){
        for (int h=0; h<100; h++){
            if ((w==20) & (h==20)){
                imageMatrix[w][h] = new RGBColor(255,255,255);
            } else {
                imageMatrix[w][h] = new RGBColor(0,0,0);
            }
        }
    }
    Picture p = new Picture(imageMatrix);
    p.rot90DegRight();
    assertTrue("The white pixel was not rotated", !(p.getImageMatrix()[20][20].isWhite()));
    assertTrue("The white pixel was not rotated", (p.getImageMatrix()[79][20].isWhite()));

}