在java中将图像旋转90度

问题描述

我设法旋转图像 180度但希望旋转它 90度 顺时针有人可以编辑我的代码，以便通过解释来完成此操作。谢谢。

I have managed to rotate an image 180 degrees but wish to rotate it 90 degrees clockwise can someone edit my code so that it does this with explanation. Thanks.

 private void rotateClockwise()
    {
        if(currentImage != null){
            int width = currentImage.getWidth();
            int height = currentImage.getHeight();
            OFImage newImage = new OFImage(width, height);
            for(int y = 0; y < height; y++) {
                for(int x = 0; x < width; x++) {
                    newImage.setPixel( x, height-y-1, currentImage.getPixel(x, y));
                }
        }
            currentImage = newImage;
            imagePanel.setImage(currentImage);
            frame.pack();
    }
    }

推荐答案

使用这种方法。

/**
 * Rotates an image. Actually rotates a new copy of the image.
 *
 * @param img The image to be rotated
 * @param angle The angle in degrees
 * @return The rotated image
 */
public static Image rotate(Image img, double angle)
{
    double sin = Math.abs(Math.sin(Math.toRadians(angle))),
           cos = Math.abs(Math.cos(Math.toRadians(angle)));

    int w = img.getWidth(null), h = img.getHeight(null);

    int neww = (int) Math.floor(w*cos + h*sin),
        newh = (int) Math.floor(h*cos + w*sin);

    BufferedImage bimg = toBufferedImage(getEmptyImage(neww, newh));
    Graphics2D g = bimg.createGraphics();

    g.translate((neww-w)/2, (newh-h)/2);
    g.rotate(Math.toRadians(angle), w/2, h/2);
    g.drawRenderedImage(toBufferedImage(img), null);
    g.dispose();

    return toImage(bimg);
}

取自我的 class。

taken from my ImageTool class.

希望它有所帮助。

这篇关于在java中将图像旋转90度的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！