Java实现的图片高质量缩放类定义与用法示例

2021-02-23 10:38CodingSir JAVA教程

这篇文章主要介绍了Java实现的图片高质量缩放类定义与用法,涉及java针对图片的运算与转换等相关操作技巧,需要的朋友可以参考下

本文实例讲述了Java实现的图片高质量缩放类定义与用法。分享给大家供大家参考，具体如下：

找了很多都不理想，最后找个到老外写的，不得不承认老外写的确实牛B。

									package com.test;

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

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

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

									import javax.swing.*;

									import java.io.File;

									import java.io.FileOutputStream;

									import java.io.IOException;

									import java.awt.*;

									import java.awt.image.BufferedImage;

									import java.awt.image.Kernel;

									import java.awt.image.ConvolveOp;

									public class ImageUtil {

									  public static void resize(File originalFile, File resizedFile,

									      int newWidth, float quality) throws IOException {

									    if (quality > 1) {

									      throw 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 > 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("C:\\1207.gif");

									     resize(originalImage, new File("c:\\1207-0.jpg"),150, 0.7f);

									     resize(originalImage, new File("c:\\1207-1.jpg"),150, 1f);

									  }

									}