java 实现图片像素质量压缩与图片长宽缩放

java 实现图片像素质量压缩与图片长宽缩放

目录java 图片像素质量压缩与图片长宽缩放java 修改图片dpi(像素/vWelDgIl大小)

java 图片像素质量压缩与图片长宽缩放

今天找到的这个方法比以前项目用到的方法更好，这里记录下，方便日后使用！

/**

* 缩放图片(压缩图片质量，改变图片尺寸)

* 若原图宽度小于新宽度，则宽度不变！

* @param newWidth 新的宽度

* @param quality 图片质量参数 0.7f 相当于70%质量

* 2015年12月11日

*/

public static void resize(File originalFile, File resizedFile,

int newWidth, float quality) throws IOException {

if (quality > 1) {

throhttp://w new IllegalArgumentException(

"Quality has to be between 0 and 1");

}

ImageIcon ii = new ImageIcon(originalFile.getCanonicalPath());

Image i = ii.getImage();

Image resizedImage = null;

int iWidth = i.getWidth(null);

int iHeight = i.getHeight(null);

if(iWidth < newWidth){

newWidth = iWidth;

}

if (iWidth > iHeight) {

resizedImage = i.getScaledInstance(newWidth, (newWidth * iHeight)

/ iWidth, Image.SCALE_SMOOTH);

} else {

resizedImage = i.getScaledInstance((newWidth * iWidth) / iHeight,

newWidth, Image.SCALE_SMOOTH);

}

// This code ensures that all the pixels in the image are loaded.

Image temp = new ImageIcon(resizedImage).getImage();

// Create the buffered image.

BufferedImage bufferedImage = new BufferedImage(temp.getWidth(null),

temp.getHeight(null), BufferedImage.TYPE_INT_RGB);

// Copy image to buffered image.

Graphics g = bufferedImage.createGraphics();

// Clear background and paint the image.

g.setColor(Color.white);

g.fillRect(0, 0, temp.getWidth(null), temp.getHeight(null));

g.drawImage(temp, 0, 0, null);

g.dispose();

// Soften.

float softenFactor = 0.05f;

float[] softenArray = { 0, softenFactor, 0, softenFactor,

1 - (softenFactor * 4), softenFactor, 0, softenFactor, 0 };

Kernel kernel = new Kernel(3, 3, softenArray);

ConvolveOp cOp = new ConvolveOp(kernel, ConvolveOp.EDGE_NO_OP, null);

bufferedImage = cOp.filter(bufferedImage, null);

// Write the jpeg to a file.

FileOutputStream out = new FileOutputStream(resizedFile);

// Encodes image as a JPEG data stream

JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);

JPEGEncodeParam param = encoder

.getDefaultJPEGEncodeParam(bufferedImage);

param.setQuality(quality, true);

encoder.setJPEGEncodeParam(param);

encoder.encode(bufferedImage);

} // Example usage

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

// File originalImage = new File("C:\\11.jpg");

// resize(originalImage, new File("c:\\11-0.jpg"),150, 0.7f);

// resize(originalImage, new File("c:\\11-1.jpg"),150, 1f);

File originalImage = new File("d:\\testImg\\1.jpg");

System.out.println("源文件大小" + originalImage.length());

// File resizedImg = new File("d:\\testImg\\11.jpg");

// resize(originalImage, resizedImg, 850, 1f);

// System.out.println("0.5转换后文件大小" + resizedImg.length());

// File resizedImg1 = new File("d:\\testImg\\111.jpg");

File resizedImg1 = new File("/alidata/zkyj/dashixiong/tempImgFile/11.jpg");

resize(originalImage, resizedImg1, 1550, 0.7f);

System.out.println("0.7转换后文件大小" + resizedImg1.length());

}

java 修改图片dpi(像素/大小)

import com.sun.image.codec.jpeg.JPEGCodec;

import com.sun.image.codec.jpeg.JPEGEncodeParam;

import com.sun.image.codec.jpeg.JPEGImageEncoder;

import javax.imageio.ImageIO;

import java.awt.image.BufferedImage;

import java.io.File;

import java.io.FileOutputStream;

import java.io.IOException;

public class DPIHandleHelper {

private static int DPI = 300;

public static void main(String[] args) {

String path = "C:\\test.jpg";

File file = new File(path);

handleDpi(file, 300, 300);

}

/**

* 改变图片DPI

*

* @param file

* @param xDensity

* @param yDensity

*/

public static void handleDhttp://pi(File file, int xDensity, int yDensity) {

try {

BufferedImage image = ImageIO.read(file);

JPEGImageEncoder jpegEncoder = JPEGCodec.createJPEGEncoder(new FileOutputStream(file));

JPEGEncodeParam jpegEncodeParam = jpegEncoder.getDefaultJPEGEncodeParam(image);

jpegEncodeParam.setDensityUnit(JPEGEncodeParam.DENSITY_UNIT_DOTS_INCH);

jpegEncoder.setJPEGEncodeParam(jpegEncodeParam);

jpegEncodeParam.setQuality(0.75f, false);

jpegEncodeParam.setXDensity(xDensity);

jpegEncodeParam.setYDensity(yDensity);

jpegEncoder.encode(image, jpegEncodeParam);

image.flush();

} catch (IOException e) {

e.printStackTrace();

}

}

}

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