This article describes the definition and usage of high-quality scaling classes implemented in Java. Share it for your reference, as follows:
I found a lot of them but were not ideal, and finally found someone who wrote them from a foreigner. I have to admit that what the foreigner wrote is indeed awesome.
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); }}For more Java-related content, readers who are interested in this site can view the topics: "Summary of Java Image Operation Skills", "Summary of Java Date and Time Operation Skills", "Summary of Java Operation DOM Node Skills", "Summary of Java File and Directory Operation Skills" and "Tutorials of Java Data Structure and Algorithm".
I hope this article will be helpful to everyone's Java programming.