我是java初学者。

我想自己做旋转，我知道如何使用图形类，但我试图理解它是如何在这些类中工作的。

我有一张从google Image中随机选择的图像。我把它变成了一个像素的数组，使用这个函数，它工作得很好：

BufferedImage immeuble = ImageIO.read( new File( "....jpg" ) );
int width = immeuble.getWidth();
int height = immeuble.getHeight();
int[] pixArray;
pixArray = Util.convertToPixels( immeuble );



public static int[] convertToPixels(Image img) {
            int width = img.getWidth(null);
            int height = img.getHeight(null);
            int[] pixel = new int[width * height];

        PixelGrabber pg = new PixelGrabber(img, 0, 0, width, height, pixel, 0, width);
        try {
            pg.grabPixels();
        } catch (InterruptedException e) {
            throw new IllegalStateException("Error: Interrupted Waiting for Pixels");
        }
        if ((pg.getStatus() & ImageObserver.ABORT) != 0) {
            throw new IllegalStateException("Error: Image Fetch Aborted");
        }
        return pixel;
    }

然后，我根据给定的角度旋转这个像素阵列。

pixArray = util.rotate( angle, pixArray, width, height );

public int[] rotate( double angle, int[] pixels, int width, int height ) {
        final double radians = Math.toRadians( angle );
        final double cos = Math.cos( radians );
        final double sin = Math.sin( radians );
        final int[ ] pixels2 = new int[ pixels.length ];
        for( int pixel = 0; pixel < pixels2.length; pixel++ ) {
            pixels2[pixel] = 0xFFFFFF;
        }
        for( int x = 0; x < width; x++ ) {
            for( int y = 0; y < height; y++ ) {
                final int centerx = width / 2;
                final int centery = height / 2;
                final int m = x - centerx;
                final int n = y - centery;
                final int j = ( ( int ) ( m * cos + n * sin ) ) + centerx;
                final int k = ( ( int ) ( n * cos - m * sin ) ) + centery;
                if( j >= 0 && j < width && k >= 0 && k < height ){
                    pixels2[ ( y * width + x ) ] = pixels[ ( k * width + j ) ];
                }
            }
        }
        return pixels2;
    }

然后，我通过旋转显示新图像，将数组（像素数组）转换为二维数组：

array2d = util.monoToMulti( pixArray, height, width );
public int[][] monoToMulti(final int[] array, final int height, final int width) {
        if (array.length != (height * width))
            throw new IllegalArgumentException("Invalid array length");

        int[][] multi = new int[height][width];

        for ( int i = 0; i < height; i++ )
            System.arraycopy(array, (i*width), multi[i], 0, width);

        return multi;
    }

并创建一个新的BufferedImage：

BufferedImage bufferedImage = new BufferedImage( array2d.length, array2d[0].length,
                                                         BufferedImage.TYPE_INT_ARGB );
        for ( int x = 0; x < array2d.length; x++ )
        {
            for ( int y = 0; y < array2d[x].length; y++ )
            {
                bufferedImage.setRGB( x, y, array2d[x][y] );
            }
        }


        util.saveToPNG( bufferedImage, "rotation_test" );

我有几个问题：

>

double angle = 18;


public void saveToPNG(Image image, String name) throws IOException {
        File f = new File (name + ".png");
        try {
            ImageIO.write((RenderedImage) image, "png", f);
        } catch (IOException e) {
            e.printStackTrace();
        }