代码如下:

public class Picture {

// TODO Auto-generated constructor stub

public static void resizePNG(String fromFile, String toFile, int outputWidth, int outputHeight,boolean proportion) {

try {

File f2 = new File(fromFile);

BufferedImage bi2 = ImageIO.read(f2);

int newWidth;

int newHeight;

// 判断是否是等比缩放

if (proportion == true) {

// 为等比缩放计算输出的图片宽度及高度

double rate1 = ((double) bi2.getWidth(null)) / (double) outputWidth + 0.1;

double rate2 = ((double) bi2.getHeight(null)) / (double) outputHeight + 0.1;

// 根据缩放比率大的进行缩放控制

double rate = rate1 < rate2 ? rate1 : rate2;

newWidth = (int) (((double) bi2.getWidth(null)) / rate);

newHeight = (int) (((double) bi2.getHeight(null)) / rate);

} else {

newWidth = outputWidth; // 输出的图片宽度

newHeight = outputHeight; // 输出的图片高度

}

BufferedImage to = new BufferedImage(newWidth, newHeight,

BufferedImage.TYPE_INT_RGB);

Graphics2D g2d = to.createGraphics();

to = g2d.getDeviceConfiguration().createCompatibleImage(newWidth,newHeight,

Transparency.TRANSLUCENT);

g2d.dispose();

g2d = to.createGraphics();

Image from = bi2.getScaledInstance(newWidth, newHeight, bi2.SCALE_AREA_AVERAGING);

g2d.drawImage(from, 0, 0, null);

g2d.dispose();

ImageIO.write(to, "png", new File(toFile));

} catch (IOException e) {

e.printStackTrace();

}

}

public static void main(String[] args) throws IOException {

System.out.println("Start");

resizePNG("C:\\Documents and Settings\\Administrator\\桌面\\8d9e9c82d158ccbf8b31059319d8bc3eb035414e.jpg", "C:\\Documents and Settings\\Administrator\\桌面\\ell.png",200, 100,true);

System.out.println("OK");

}

}

时间： 2014-04-12