java调准图片代码,java调整图片大小

怎么用java代码放大或缩小图片不失真。

放大图像不会导致失真，而缩小图像将不可避免的失真。

Java中也同样是这样。

但java提供了4个缩放的微调选项。

image.SCALE_SMOOTH

//平滑优先

image.SCALE_FAST//速度优先

image.SCALE_AREA_AVERAGING

//区域均值

image.SCALE_REPLICATE

//像素复制型缩放

image.SCALE_DEFAULT

//默认缩放模式

调用方法

Image

new_img=old_img.getScaledInstance(1024,

768,

Image.SCALE_SMOOTH);

得到一张缩放后的新图。

相关问答

Q1: java如何修改图片大小

截取点代码片断，你自己看着改

修改图片大小用getScaledInstance方法

BufferedImage bimg = null;

Image img = null;

int width, height;

try {

bimg = ImageIO.read(u);

if(bimg.getWidth()  bimg.getHeight())

{

width = 40;

height = bimg.getHeight() * width / bimg.getWidth();

}

else

{

height = 40;

width = bimg.getWidth() * height / bimg.getHeight();

}

img = bimg.getScaledInstance(width, height, Image.SCALE_DEFAULT);

pre_image = bimg.getScaledInstance(width * 10, height * 10, Image.SCALE_DEFAULT);

} catch (IOException e) {

e.printStackTrace();

}

Q2: java设置插入图片大小

可以用Image中的getScaledInstance方法得到一个按照指定宽度和高度缩放以后的Image实例，然后再用setImage方法设置ImageIcon所显示的图像

一下示例：

×××××××××××××××××××××××××××××

import javax.swing.*;

import java.awt.*;

public class test extends JFrame

{

private ImageIcon img;

private JLabel showImg;

private final static int WIDTH=147;

private final static int HEIGHT=136;

public test()

{

img=new ImageIcon("1.png");

img.setImage(img.getImage().getScaledInstance(test.WIDTH,test.HEIGHT,Image.SCALE_DEFAULT));

showImg=new JLabel();

showImg.setIcon(img);

this.add(showImg,BorderLayout.CENTER);

this.setBounds(300,200,400,300);

this.pack();

this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

this.setVisible(true);

}

public static void main(String args[])

{

new test();

}

}

Q3: java 通过 路径 来调用已有图片（或其他任何文件）的代码怎么写？

Class.getResource("")    返回的是当前Class这个类所在包开始的位置

举例

URL url = XXXX.class.getResource("");

System.out.println(url);

//输出file:/D:/space/workspace/JDK8/bin/a/

所以a文件下的图片 不需要写 /1.jpg  而直接写 1.jpg

URL url = XXXX.class.getResource("1.jpg");

ImageIcon对象的构造方法很多

比如写图片路径来构造

相对路径的写法

ImageIcon icon = new ImageIcon("src\\a\\50.png");

完整路径,

ImageIcon icon = new ImageIcon("D:\\space\\workspace\\JDK8\\src\\a\\50.png");

使用完整路径,可以加载电脑上的其他位置的图片

比如  ImageIcon icon = new ImageIcon("c:\\50.png");

在图片上右键单击------选择Properties-------弹出对话框里有Location信息

这个信息就是完整路径

Q4: 高分求java代码，用来生成图片文件！！

//defaultSuffix是jpg

public static final boolean resizeImage(String fileName, String suffix) throws Exception {

boolean uploaded = false;

BufferedImage input;

if(suffix.equalsIgnoreCase("tif")||suffix.equalsIgnoreCase("tiff")||suffix.equalsIgnoreCase("png")) {

RenderedImage image = JAI.create("fileload", TurbineServlet.getRealPath(imageRoot + fileName+"."+suffix));

WritableRaster raster = image.copyData(null);

BufferedImage bi = new BufferedImage( image.getColorModel(), raster, true, null);

BufferedImage bi2 = new BufferedImage( maxResizeDimension, bi.getHeight()*maxResizeDimension/bi.getWidth(), BufferedImage.TYPE_INT_RGB);

Graphics2D g2 = bi2.createGraphics();

g2.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR);

g2.setBackground(java.awt.Color.WHITE);//把tiff和png转换后的背景设置为白色

g2.fillRect(0, 0, maxResizeDimension, bi.getHeight()*maxResizeDimension/bi.getWidth());

g2.drawImage(bi, 0, 0, maxResizeDimension, bi.getHeight()*maxResizeDimension/bi.getWidth(), null);

PlanarImage pi = PlanarImage.wrapRenderedImage(bi2);

JAI.create("FileStore", pi, TurbineServlet.getRealPath(resizeRoot + fileName+"."+defaultSuffix).replaceAll("\\\\","\\\\\\\\"), "JPEG", new JPEGEncodeParam());

input = pi.getAsBufferedImage();

int w = maxThumbDimension, h = maxThumbDimension;

BufferedImage output = new BufferedImage(w, h, BufferedImage.TYPE_3BYTE_BGR);

Graphics2D g = output.createGraphics();

g.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR);

g.drawImage(input,0,0,w,h, null);

ImageIO.write(output, defaultSuffix, new File(TurbineServlet.getRealPath(thumbRoot + fileName+"."+defaultSuffix)));

}

else {

input = ImageIO.read(new File(TurbineServlet.getRealPath(imageRoot + fileName+"."+suffix)));

int w = maxThumbDimension, h = maxThumbDimension;

BufferedImage output = new BufferedImage(w, h, BufferedImage.TYPE_3BYTE_BGR);

Graphics2D g = output.createGraphics();

g.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR);

g.drawImage(input,0,0,w,h, null);

ImageIO.write(output, defaultSuffix, new File(TurbineServlet.getRealPath(thumbRoot + fileName+"."+defaultSuffix)));

BufferedImage output2 = new BufferedImage(maxResizeDimension, input.getHeight()*maxResizeDimension/input.getWidth(), BufferedImage.TYPE_3BYTE_BGR);

Graphics2D g2 = output2.createGraphics();

g2.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR);

g2.drawImage(input,0,0,maxResizeDimension, input.getHeight()*maxResizeDimension/input.getWidth(), null);

ImageIO.write(output2, defaultSuffix, new File(TurbineServlet.getRealPath(resizeRoot + fileName+"."+defaultSuffix)));

}

uploaded = true;

return uploaded;

}