Java2D图像轮换问题 [英] Java2D Image Rotation Issue
本文介绍了Java2D图像轮换问题的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我使用以下代码来旋转给定的图像。
I am using following code to rotate an given image.
public int getImageWidth(BufferedImage img) {
if (rotate == Rotate.UPSIDE_DOWN || rotate == Rotate.ABOUT_CENTER)
return img.getWidth();
else
return img.getHeight();
}
public int getImageHeight(BufferedImage img) {
if (rotate == Rotate.UPSIDE_DOWN || rotate == Rotate.ABOUT_CENTER)
return img.getHeight();
else
return img.getWidth();
}
这是轮换枚举
public enum Rotate {
DOWN, UP, UPSIDE_DOWN, ABOUT_CENTER;
}
实际轮换方式
public BufferedImage rotateImage(BufferedImage source, int x, int y,
float orientation) throws Exception {
int newWidth = getImageWidth(source);
int newHeight = getImageHeight(source);
int cWidth = newWidth / 2;
int cHeight = newHeight / 2;
int imgType = source.getType() == 0 ? 5 : source.getType();
BufferedImage result = new BufferedImage(getImageWidth(source),
getImageHeight(source),imgType);
Graphics2D g2 = result.createGraphics();
if (rotate == Rotate.DOWN) {
g2.translate(x + cHeight, y + cWidth);
g2.rotate(Math.toRadians(90));
g2.drawImage(source, 0, 0, newWidth, newHeight, null);
} else if (rotate == Rotate.UP) {
g2.translate(x + cHeight, y + cWidth);
g2.rotate(Math.toRadians(-90));
g2.drawImage(source, 0, 0, newWidth, newHeight, null);
} else if (rotate == Rotate.UPSIDE_DOWN) {
g2.translate(x + cWidth, y + cHeight);
g2.rotate(Math.toRadians(180));
g2.drawImage(source, 0, 0, newWidth, newHeight, null);
} else if (rotate == Rotate.ABOUT_CENTER) {
Rectangle r = new Rectangle(x, y, newWidth, newHeight);
g2.setClip(r);
AffineTransform original = g2.getTransform();
AffineTransform at = new AffineTransform();
at.concatenate(original);
at.rotate(orientation, x + cWidth, y + cHeight);
g2.setTransform(at);
g2.drawImage(source, 0, 0, newWidth, newHeight, null);
g2.setTransform(original);
}
g2.dispose();
g2 = null;
return result;
}
客户代码
// rotate derived & filtered image to 90 degree
// using Affine transform
setRotate(Rotate.UP);
BufferedImage rSubImage = rotateImage(fSubImage, 0, 0, -90);
现在以下是源图像,
当我旋转此图像时使用上面的代码,结果很奇怪
When i rotate this image using above code , the result is very strange
我做错了什么?
轮换后质量也会丢失,请注意。
推荐答案
我认为解决方案是使用AffineTranform,将Image翻译成中心的reamin。我修改了你的代码并对其进行了测试,对我来说它是有效的:
I think the solution is to use AffineTranform, translating the Image to reamin in the center. I modified your code and tested it, for me it works:
public BufferedImage rotateImage(BufferedImage source, int x, int y,
float orientation) throws Exception {
int newWidth = getImageWidth(source);
int newHeight = getImageHeight(source);
int imgType = source.getType() == 0 ? 5 : source.getType();
BufferedImage result = new BufferedImage(getImageWidth(source),
getImageHeight(source), imgType);
if (rotate == Rotate.DOWN) {
AffineTransform tranform = new AffineTransform();
tranform.translate(newWidth / 2, newHeight / 2);
tranform.rotate(Math.toRadians(90));
tranform.translate(-source.getWidth()/2, -source.getHeight()/2);
Graphics2D g2d = result.createGraphics();
g2d.drawImage(source, tranform, null);
} else if (rotate == Rotate.UP) {
AffineTransform tranform = new AffineTransform();
tranform.translate(newWidth / 2, newHeight / 2);
tranform.rotate(Math.toRadians(-90));
tranform.translate(-source.getWidth()/2, -source.getHeight()/2);
Graphics2D g2d = result.createGraphics();
g2d.drawImage(source, tranform, null);
} else if (rotate == Rotate.UPSIDE_DOWN) {
AffineTransform tranform = new AffineTransform();
tranform.translate(newWidth / 2, newHeight / 2);
tranform.rotate(Math.toRadians(180));
tranform.translate(-source.getWidth()/2, -source.getHeight()/2);
Graphics2D g2d = result.createGraphics();
g2d.drawImage(source, tranform, null);
} else if (rotate == Rotate.ABOUT_CENTER) {
//......
}
return result;
}
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