java - 如何缩放 BufferedImage

Question

按照 javadocs，我尝试缩放 BufferedImage 没有成功这是我的代码:

BufferedImage image = MatrixToImageWriter.getBufferedImage(encoded);
Graphics2D grph = image.createGraphics();
grph.scale(2.0, 2.0);
grph.dispose();

我不明白为什么它不起作用，有什么帮助吗？

Answer 1

AffineTransformOp提供了选择插值类型的额外灵 active 。

BufferedImage before = getBufferedImage(encoded);
int w = before.getWidth();
int h = before.getHeight();
BufferedImage after = new BufferedImage(w, h, BufferedImage.TYPE_INT_ARGB);
AffineTransform at = new AffineTransform();
at.scale(2.0, 2.0);
AffineTransformOp scaleOp = 
   new AffineTransformOp(at, AffineTransformOp.TYPE_BILINEAR);
after = scaleOp.filter(before, after);

显示的片段说明了resampling ，而不是 cropping ;这个相关的answer地址issue ;检查了一些相关示例here .