压缩图片 · java development

[TOC] # 压缩图片 ## 1. 不改变宽高 1. 通过改变像素只改变内容大小，不改变宽高 ``` package net.aexit.zongjian.ent.common.utils; import javax.imageio.IIOImage; import javax.imageio.ImageIO; import javax.imageio.ImageWriteParam; import javax.imageio.ImageWriter; import java.awt.image.BufferedImage; import java.awt.image.ColorModel; import java.io.ByteArrayInputStream; import java.io.ByteArrayOutputStream; import java.io.IOException; public class ImageCompressUtil { /** * 压缩图片，修改像素尺寸不变 * @param imgBytes 字节 * @param qality 压缩比例 0~1 * @param format 图片格式 * @return 字节 * @throws IOException */ public static byte[] compressPictureByQality(byte[] imgBytes, float qality,String format) throws IOException { BufferedImage src; ByteArrayOutputStream outStream = null; ImageWriter imgWrier; ImageWriteParam imgWriteParams; ByteArrayInputStream inputStream =null; byte[] rtnByte = null; try { // 指定写图片的方式为 jpg imgWrier = ImageIO.getImageWritersByFormatName(format).next(); imgWriteParams = new javax.imageio.plugins.jpeg.JPEGImageWriteParam( null); // 要使用压缩，必须指定压缩方式为MODE_EXPLICIT imgWriteParams.setCompressionMode(imgWriteParams.MODE_EXPLICIT); // 这里指定压缩的程度，参数qality是取值0~1范围内， imgWriteParams.setCompressionQuality(qality); imgWriteParams.setProgressiveMode(imgWriteParams.MODE_DISABLED); inputStream = new ByteArrayInputStream(imgBytes); ColorModel colorModel = ImageIO.read(inputStream).getColorModel();// ColorModel.getRGBdefault(); imgWriteParams.setDestinationType(new javax.imageio.ImageTypeSpecifier( colorModel, colorModel.createCompatibleSampleModel(32, 32))); inputStream = new ByteArrayInputStream(imgBytes); src = ImageIO.read(inputStream); outStream = new ByteArrayOutputStream(); imgWrier.reset(); imgWrier.setOutput(ImageIO.createImageOutputStream(outStream)); // 调用write方法，就可以向输入流写图片 imgWrier.write(null, new IIOImage(src, null, null), imgWriteParams); rtnByte = outStream.toByteArray(); } finally { if (outStream != null) { outStream.close(); } if (inputStream != null) { inputStream.close(); } } return rtnByte; } public static void main(String args[]) throws Exception { // ImageCompressUtil.saveMinPhoto("C:\\Users\\1\\Desktop\\Snapshots\\\\20180907_10.55.08_8068.jpg", "C:\\Users\\1\\Desktop\\Snapshots\\20180907_10.44.05_8068副本.jpg", 800, 1); } } ``` ## 2. 改变宽高 ``` package com.aixin.tuna.workflow.util; import java.awt.Image; import java.awt.image.BufferedImage; import java.io.File; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import javax.imageio.ImageIO; import com.sun.image.codec.jpeg.JPEGCodec; import com.sun.image.codec.jpeg.JPEGEncodeParam; import com.sun.image.codec.jpeg.JPEGImageEncoder; public class ImageCompressUtil { /** * 直接指定压缩后的宽高： * (先保存原文件，再压缩、上传) * 壹拍项目中用于二维码压缩 * @param oldFile 要进行压缩的文件全路径 * @param width 压缩后的宽度 * @param height 压缩后的高度 * @param quality 压缩质量 * @param smallIcon 文件名的小小后缀(注意，非文件后缀名称),入压缩文件名是yasuo.jpg,则压缩后文件名是yasuo(+smallIcon).jpg * @return 返回压缩后的文件的全路径 */ public static String zipImageFile(String oldFile, int width, int height, float quality, String smallIcon) { if (oldFile == null) { return null; } String newImage = null; try { /**对服务器上的临时文件进行处理 */ Image srcFile = ImageIO.read(new File(oldFile)); /** 宽,高设定 */ BufferedImage tag = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB); tag.getGraphics().drawImage(srcFile, 0, 0, width, height, null); String filePrex = oldFile.substring(0, oldFile.indexOf('.')); /** 压缩后的文件名 */ newImage = filePrex + smallIcon + oldFile.substring(filePrex.length()); /** 压缩之后临时存放位置 */ FileOutputStream out = new FileOutputStream(newImage); JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out); JPEGEncodeParam jep = JPEGCodec.getDefaultJPEGEncodeParam(tag); /** 压缩质量 */ jep.setQuality(quality, true); encoder.encode(tag, jep); out.close(); } catch (FileNotFoundException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } return newImage; } /** * 保存文件到服务器临时路径(用于文件上传) * @param fileName * @param is * @return 文件全路径 */ public static String writeFile(String fileName, InputStream is) { if (fileName == null || fileName.trim().length() == 0) { return null; } try { /** 首先保存到临时文件 */ FileOutputStream fos = new FileOutputStream(fileName); byte[] readBytes = new byte[512];// 缓冲大小 int readed = 0; while ((readed = is.read(readBytes)) > 0) { fos.write(readBytes, 0, readed); } fos.close(); is.close(); } catch (FileNotFoundException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } return fileName; } /** * 等比例压缩算法： * 算法思想：根据压缩基数和压缩比来压缩原图，生产一张图片效果最接近原图的缩略图 * @param srcURL 原图地址 * @param deskURL 缩略图地址 * @param comBase 压缩基数 * @param scale 压缩限制(宽/高)比例一般用1： * 当scale>=1,缩略图height=comBase,width按原图宽高比例;若scale<1,缩略图width=comBase,height按原图宽高比例 * @throws Exception * @author shenbin * @createTime 2014-12-16 * @lastModifyTime 2014-12-16 */ public static void saveMinPhoto(String srcURL, String deskURL, double comBase, double scale) throws Exception { File srcFile = new java.io.File(srcURL); Image src = ImageIO.read(srcFile); int srcHeight = src.getHeight(null); int srcWidth = src.getWidth(null); int deskHeight = 0;// 缩略图高 int deskWidth = 0;// 缩略图宽 double srcScale = (double) srcHeight / srcWidth; /**缩略图宽高算法*/ if ((double) srcHeight > comBase || (double) srcWidth > comBase) { if (srcScale >= scale || 1 / srcScale > scale) { if (srcScale >= scale) { deskHeight = (int) comBase; deskWidth = srcWidth * deskHeight / srcHeight; } else { deskWidth = (int) comBase; deskHeight = srcHeight * deskWidth / srcWidth; } } else { if ((double) srcHeight > comBase) { deskHeight = (int) comBase; deskWidth = srcWidth * deskHeight / srcHeight; } else { deskWidth = (int) comBase; deskHeight = srcHeight * deskWidth / srcWidth; } } } else { deskHeight = srcHeight; deskWidth = srcWidth; } BufferedImage tag = new BufferedImage(deskWidth, deskHeight, BufferedImage.TYPE_3BYTE_BGR); tag.getGraphics().drawImage(src, 0, 0, deskWidth, deskHeight, null); //绘制缩小后的图 FileOutputStream deskImage = new FileOutputStream(deskURL); //输出到文件流 JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(deskImage); encoder.encode(tag); //近JPEG编码 deskImage.close(); } public static void main(String args[]) throws Exception { // ImageCompressUtil.zipImageFile("C:\\Users/*/\\1\\Desktop\\1.png", 1280, 1280, 1f, "-副本"); ImageCompressUtil.saveMinPhoto("C:\\Users\\1\\Desktop\\1.png", "C:\\Users\\1\\Desktop\\1-副本1.png", 500, 1); } } ```