程序博客网 > 软件开源有什么用

java 图片压缩、缩放

来源：互联网 发布：软件开源有什么用 编辑：程序博客网 时间：2024/05/22 06:41
对图像的缩放可以带来很多好处，比如在载入图像时可以有效减少各方面的压力。 
这里依靠thumbnailator、imgscalr这两个jar包分别实现。 
为了能够粗粒度的控制压缩，定义一个ScalrConfig来控制图像尺寸，图像类型(JPG、BMP。。。。)等。
  1. public class ScalrConfig {
  2. //图片质量
  3. private Float quality = 1F;
  4. //图片高度
  5. private int height = 600;
  6. //图片宽度
  7. private int width = 600;
  8. //使长或宽适应到某一个长度
  9. private Integer size ;
  10. //重写format
  11. private ImageExtensionEnum type = ImageExtensionEnum.JPG;
  12. //是否重写
  13. private boolean retype = true;
  14. //保持横纵比
  15. private boolean aspectRatio = true;
  16. //压缩过滤
  17. private ScalrFilter filter;
  19. public ScalrConfig(int size,int allowWidth,
  20. int allowHeight){
  21. this.size = size;
  22. this.filter = new DefautlScalrFiter(allowWidth,allowHeight);
  23. }
  25. public ScalrConfig(int width,int height,
  26. int allowWidth,int allowHeight){
  27. this.height = height;
  28. this.width = width;
  29. this.filter = new DefautlScalrFiter(allowWidth,allowHeight);
  30. }
  32. class DefautlScalrFiter implements ScalrFilter{
  34. private int allowWidth;
  36. private int allowHeight;
  37.  
  38. @Override
  39. public boolean doFilter(int _width, int _height) {
  40. return allowWidth < _width || allowHeight < _height;
  41. }
  42.  
  43. public DefautlScalrFiter(int allowWidth, int allowHeight) {
  44. this.allowWidth = allowWidth;
  45. this.allowHeight = allowHeight;
  46. }
  47. }
  48. //省略setter、getter

ImageExtensionEnum用来定义图片格式（GIF不支持。。。。）

  1. public enum ImageExtensionEnum {
  3. JPG,JPEG,PNG,BMP,GIF;
  5. public final static String [] getExtensions(){
  6. ImageExtensionEnum enums [] = ImageExtensionEnum.values();
  7. String [] extensions = new String [enums.length];
  8. for(int i=0;i<enums.length;i++)
  9. extensions[i] = enums[i].name();
  10. return extensions;
  11. }
  13. public static boolean isJPG(String extension){
  14. return JPEG.name().equalsIgnoreCase(extension) || 
  15. JPG.name().equalsIgnoreCase(extension);
  16. }
  18. public static boolean isSameType(String extension1,String extension2){
  19.     if(extension1 == null || extension2 == null) return false;
  20.     return (extension1.equalsIgnoreCase(extension2))||
  21.     (isJPG(extension1)&&isJPG(extension2))?true : false;
  22.     }
  23. }
ScalrFilter用来控制图片是否需要被压缩，如果图片过小，此时缩放是不明智的。
  1. public interface ScalrFilter {
  3. public boolean doFilter(int _width,int _height);
  4.  
  5. }
下面是图片压缩:
  1. public interface Thumbnailer {
  3. /**
  4.  * 
  5.  * @param is 图片文件流
  6.  * @param size 图片大小
  7.  * @param config 配置
  8.  * @param extension 图片后缀
  9.  * @return
  10.  * @throws Exception
  11.  */
  12. List<ThumbnailResult> createThumbnails(File file,
  13. ScalrConfig...configs) throws Exception;
  14.  
  15. }
thumnailResult是一个接口，用来控制缩放成文件、写入输出流、返回缩放后的图片类型和大小:
  1. public interface ThumbnailResult {
  3. File writeToFile(File destFile) throws Exception;
  5. void writeToStream(OutputStream stream) throws Exception;
  7. int getWidth() throws Exception;
  9. int getHeight() throws Exception;
  11. String getExtension();
  12.  
  14. }
最后读取、判断文件：
  1. public abstract class AbstractThumbaniler implements Thumbnailer{
  3. @Override
  4. public List<ThumbnailResult> createThumbnails(File file,
  5. ScalrConfig... configs) throws Exception {
  6. if(configs == null || configs.length == 0)
  7. {
  8. throw new IllegalArgumentException("必须指定一个 ScalrConfig");
  9. }
  10. if (file == null)
  11. {
  12. throw new IllegalArgumentException("文件不能为空");
  13. }
  14. if (!file.exists())
  15. {
  16. throw new IllegalArgumentException(file.getAbsolutePath() + "不存在");
  17. }
  18. String oldExtension = MyStringUtils.getFilenameExtension(file.getName());
  19. if(!isSupportedOutputFormat(oldExtension))
  20. {
  21. throw new IllegalArgumentException("文件不符合格式");
  22. }
  23. BufferedImage image = ImageIO.read(file);
  24. if (image == null)
  25. {
  26. throw new IllegalArgumentException("文件不是一个真正的图片");
  27. }
  28. List<ThumbnailResult> results = new ArrayList<ThumbnailResult>();
  29. for(ScalrConfig config : configs)
  30. {
  31. ScalrFilter filter = config.getFilter();
  32. if(filter == null || (filter != null && 
  33.     filter.doFilter(image.getWidth(), image.getHeight())))
  34.  {
  35. results.add(createThumbnail(image, config,oldExtension));
  36. }
  37. }
  38. return results;
  39. }
  41. abstract ThumbnailResult createThumbnail(BufferedImage image,
  42. ScalrConfig config,String oldExtension) throws Exception;
  44. protected List<String> getSupportedOutputFormats(){
  46. String[] formats = ImageIO.getWriterFormatNames();
  47. if (formats == null)
  48. {
  49. return Collections.emptyList();
  50. }
  51. else
  52. {
  53. return Arrays.asList(formats);
  54. }
  55. }
  57. private boolean isSupportedOutputFormat(String format){
  58. for (String supportedFormat : getSupportedOutputFormats())
  59. {
  60. if (supportedFormat.equals(format))
  61. {
  62. return true;
  63. }
  64. }
  66. return false;
  67. }
  68.  
  69. }

首先是 thumbnailator，它的使用非常简单！ 
项目地址(请自觉翻墙): 
http://code.google.com/p/thumbnailator/ 
它能够按照比例缩让、固定尺寸缩放、打水印、旋转和切割等各种的功能，牛逼的是完成这些功能只需要一行代码即可，例如:
  1. Thumbnails.of(new File("q:/user.bmp")).scale(0.25F).toFile(new File("q:/dest.bmmp"));
  2. Thumbnails.of(new File("q:/user.bmp")).size(300, 300).toFile(new File("q:/dest.bmmp"));
  3. Thumbnails.of(new File("q:/user.bmp")).size(300,300).
  4.                        keepAspectRatio(false).toFile(newFile("q:/dest.bmmp"));
下面是具体的使用:
  1. public class CoobirdThumbnailer extends AbstractThumbaniler {
  2.  
  3. @Override
  4. ThumbnailResult createThumbnail(BufferedImage image, ScalrConfig config,
  5. String oldExtension)throws Exception {
  6. int width = image.getWidth();
  7. int height = image.getHeight();
  8. this.calc(config, width, height);
  9. final Builder<BufferedImage> builder = Thumbnails.of(image);
  10. builder.size(config.getWidth(), config.getHeight())
  11. .keepAspectRatio(config.getAspectRatio());
  12. if (config.isRetype())
  13. {
  14. String newExtension = config.getType().name();
  15. if (!ImageExtensionEnum.isSameType(newExtension, oldExtension))
  16. oldExtension = newExtension;
  17. }
  18. builder.outputFormat(oldExtension);
  19. if (ImageExtensionEnum.isJPG(oldExtension)
  20. && config.getQuality() != null)
  21. {
  22. builder.outputQuality(config.getQuality());
  23. }
  24. return new CoobirdThumbnailResult(builder, oldExtension);
  25. }
  26.  
  27. private ScalrConfig calc(ScalrConfig config, int _width, int _height) {
  28. Integer size = config.getSize();
  29. if (size != null) {
  30. config.setAspectRatio(false);
  31. double sourceRatio = (double) _width / (double) _height;
  32. if (_width >= _height)
  33. {
  34. config.setWidth(size);
  35. config.setHeight((int) Math.round(size / sourceRatio));
  36. }
  37. if (_width < _height)
  38. {
  39. config.setHeight(size);
  40. config.setWidth((int) Math.round(size * sourceRatio));
  41. }
  42. }
  43. return config;
  44. }
  45.  
  46. private final class CoobirdThumbnailResult implements ThumbnailResult {
  47.  
  48. private Builder<BufferedImage> builder;
  49.  
  50. private String extension;
  51.  
  52. private CoobirdThumbnailResult(Builder<BufferedImage> builder,
  53. String extension) {
  54. super();
  55. this.builder = builder;
  56. this.extension = extension;
  57. }
  58.  
  59. @Override
  60. public File writeToFile(File destFile) throws Exception {
  61. String fileName = destFile.getName();
  62. String _extension = MyStringUtils.getFilenameExtension(fileName);
  63. if (!extension.equalsIgnoreCase(_extension))
  64. {
  65. destFile = new File(destFile.getParent(), fileName.concat(".")
  66. .concat(extension));
  67. }
  68. builder.toFile(destFile);
  69. return destFile;
  70. }
  71.  
  72. @Override
  73. public void writeToStream(OutputStream stream) throws Exception {
  74. builder.toOutputStream(stream);
  75. }
  76.  
  77. @Override
  78. public int getWidth() throws IOException {
  79. return builder.asBufferedImage().getWidth();
  80. }
  81.  
  82. @Override
  83. public int getHeight() throws IOException {
  84. return builder.asBufferedImage().getHeight();
  85. }
  86.  
  87. @Override
  88. public String getExtension() {
  89. return extension;
  90. }
  91. }
  92.  
  93. }

imgscalr，同样拥有图片压缩、裁剪等功能，使用同样非常简单。不过它好像没有输出到文件或者输出到流的功能（也许我没发现），它还支持多线程压缩？，感兴趣的可以看看 org.imgscalr.AsyncScalr 
项目地址: 
https://github.com/thebuzzmedia/imgscalr 或者 http://www.thebuzzmedia.com/software/imgscalr-java-image-scaling-library/ 
官网上的例子:
  1. BufferedImage thumbnail =
  2.   Scalr.resize(image, Scalr.Method.SPEED, Scalr.Mode.FIT_TO_WIDTH,
  3.                150, 100, Scalr.OP_ANTIALIAS);
具体使用:
  1. public class ImageScalrThumbnailer extends AbstractThumbaniler{
  2.  
  3. @Override
  4. ThumbnailResult createThumbnail(BufferedImage image, ScalrConfig config,
  5. String oldExtension) throws Exception {
  6. Integer size = config.getSize();
  7. if(size != null)
  8. {
  9. image = Scalr.resize(image, Method.QUALITY, size);
  10. }
  11. else
  12. {
  13. if(!config.getAspectRatio())
  14. {
  15. image = Scalr.resize(image, Method.QUALITY,
  16. Mode.FIT_EXACT,config.getWidth(),config.getHeight());
  17. }
  18. else
  19. {
  20. image = Scalr.resize(image, Method.QUALITY,
  21. config.getWidth(),config.getHeight());
  22. }
  23. }
  24. if (config.isRetype())
  25. {
  26. String newExtension = config.getType().name();
  27. if (!ImageExtensionEnum.isSameType(newExtension, oldExtension))
  28. oldExtension = newExtension;
  29. }
  30. return new ImgScalrThumbnailResult(oldExtension,
  31. config.getQuality(),image);
  32. }
  34. private final class ImgScalrThumbnailResult implements ThumbnailResult{
  36. private String extension ;
  38. private Float quality;
  40. private BufferedImage image;
  41.  
  42. @Override
  43. public File writeToFile(File destFile) throws Exception {
  44. String filename = destFile.getName();
  45. String targetExtension = MyStringUtils.getFilenameExtension(filename);
  46. if(!ImageExtensionEnum.isSameType(extension, targetExtension))
  47. {
  48. destFile = new File(destFile.getParent(),
  49. filename.concat(".").concat(extension));
  50. }
  51. ImageUtils.write(image, extension, quality, destFile);
  52. return destFile;
  53. }
  54.  
  55. @Override
  56. public void writeToStream(OutputStream stream) throws Exception {
  57. ImageUtils.write(image, extension, quality, stream);
  58. }
  59.  
  60. @Override
  61. public int getWidth() {
  62. return image.getWidth();
  63. }
  64.  
  65. @Override
  66. public int getHeight() {
  67. return image.getHeight();
  68. }
  69.  
  70. @Override
  71. public String getExtension(){
  72. return extension;
  73. }
  74.  
  75. private ImgScalrThumbnailResult(String extension, Float quality,
  76. BufferedImage image) {
  77. this.extension = extension;
  78. this.quality = quality;
  79. this.image = image;
  80. }
  82. }
  83.  
  84.  
  85. }
ImageUtils用来讲BufferedImage输出到文件或者流，具体如下（来源于Thumbanailator的util）:
  1. public final class ImageUtils {
  3. public static void write(BufferedImage img , String formatName,
  4. Float quality,File destFile) throws IOException{
  5. Iterator<ImageWriter> writers =
  6. ImageIO.getImageWritersByFormatName(formatName);
  7. if (!writers.hasNext())
  8. {
  9. throw new UnsupportedFormatException(
  10. formatName,
  11. "No suitable ImageWriter found for " + formatName + "."
  12. );
  13. }
  14. ImageWriter writer = writers.next();
  15. ImageWriteParam writeParam = writer.getDefaultWriteParam();
  16. if (writeParam.canWriteCompressed())
  17. {
  18. writeParam.setCompressionMode(ImageWriteParam.MODE_EXPLICIT);
  19. List<String> supportedFormats =
  20. ThumbnailatorUtils.getSupportedOutputFormatTypes(formatName);
  22. if (!supportedFormats.isEmpty())
  23. {
  24. writeParam.setCompressionType(supportedFormats.get(0));
  25. }
  26. if(quality != null)
  27. {
  28. writeParam.setCompressionQuality(quality);
  29. }
  30. }
  31. ImageOutputStream ios;
  32. FileOutputStream fos;
  33. fos = new FileOutputStream(destFile);
  34. ios = ImageIO.createImageOutputStream(fos);
  35. if (ios == null || fos == null)
  36. {
  37. throw new IOException("Could not open output file.");
  38. }
  39. if (
  40. formatName.equalsIgnoreCase("jpg")
  41. || formatName.equalsIgnoreCase("jpeg")
  42. || formatName.equalsIgnoreCase("bmp")
  43. )
  44. {
  45. int width = img.getWidth();
  46. int height = img.getHeight();
  47. BufferedImage newImage = new BufferedImage(width, height,
  48. BufferedImage.TYPE_INT_RGB);
  49. Graphics g = newImage.createGraphics();
  50. g.drawImage(img, 0, 0, null);
  51. g.dispose();
  52. img = newImage;
  53. }
  54. writer.setOutput(ios);
  55. writer.write(null, new IIOImage(img, null, null), writeParam);
  56. writer.dispose();
  57. ios.close();
  58. fos.close();
  59. }
  61. public static void write(BufferedImage img,String formatName,
  62. Float quality,OutputStream os) throws IOException{
  63. Iterator<ImageWriter> writers =
  64. ImageIO.getImageWritersByFormatName(formatName);
  65. if (!writers.hasNext())
  66. {
  67. throw new UnsupportedFormatException(
  68. formatName,
  69. "No suitable ImageWriter found for " + formatName + "."
  70. );
  71. }
  72. ImageWriter writer = writers.next();
  73. ImageWriteParam writeParam = writer.getDefaultWriteParam();
  74. if (writeParam.canWriteCompressed())
  75. {
  76. writeParam.setCompressionMode(ImageWriteParam.MODE_EXPLICIT);
  77. List<String> supportedFormats =
  78. ThumbnailatorUtils.getSupportedOutputFormatTypes(formatName);
  80. if (!supportedFormats.isEmpty())
  81. {
  82. writeParam.setCompressionType(supportedFormats.get(0));
  83. }
  84. if (quality != null)
  85. {
  86. writeParam.setCompressionQuality(quality);
  87. }
  88. }
  89. ImageOutputStream ios = ImageIO.createImageOutputStream(os);
  90. if (ios == null)
  91. {
  92. throw new IOException("Could not open OutputStream.");
  93. }
  94. if (
  95. formatName.equalsIgnoreCase("jpg")
  96. || formatName.equalsIgnoreCase("jpeg")
  97. || formatName.equalsIgnoreCase("bmp")
  98. )
  99. {
  100. int width = img.getWidth();
  101. int height = img.getHeight();
  102. BufferedImage newImage = new BufferedImage(width, height,
  103. BufferedImage.TYPE_INT_RGB);
  104. Graphics g = newImage.createGraphics();
  105. g.drawImage(img, 0, 0, null);
  106. g.dispose();
  107. img = newImage;
  108. }
  109. writer.setOutput(ios);
  110. writer.write(null, new IIOImage(img, null, null), writeParam);
  111. writer.dispose();
  112. ios.close();
  113. }
  114.  
  115. }
MyStringUitls主要用来获取文件后缀名: 
 
  1. public class MyStringUtils {
  3. private static final char EXTENSION_SEPARATOR = '.';
  5. private static final String FOLDER_SEPARATOR = "/";
  7. public static String getFilenameExtension(String path) {
  8. if (path == null) {
  9. return null;
  10. }
  11. int extIndex = path.lastIndexOf(EXTENSION_SEPARATOR);
  12. if (extIndex == -1) {
  13. return null;
  14. }
  15. int folderIndex = path.lastIndexOf(FOLDER_SEPARATOR);
  16. if (folderIndex > extIndex) {
  17. return null;
  18. }
  19. return path.substring(extIndex + 1);
  20. }
  21.  
  22. }

测试:
 

  1. public class Test {
  3. public static void main(String [] args) throws Exception{
  4. Thumbnailer thumbnailer = ThumbnailerFactory.getThumbnailer();
  5. File toThumbnail = new File("q:/user.bmp");
  6. ScalrConfig config = new ScalrConfig(104,105, 160,160);
  7. config.setAspectRatio(true);
  8. config.setQuality(1F);
  9. config.setType(ImageExtensionEnum.BMP);
  10. List<ThumbnailResult> results = thumbnailer.
  11. createThumbnails(toThumbnail, config);
  12. if(!results.isEmpty())
  13. {
  14. File destFile = new File("q:/target22222.bmp");
  15. ThumbnailResult result = results.get(0);
  16. result.writeToFile(destFile);
  17. }
  18. }
  21. }
0 0
软件开源有什么用 软件开源有什么用
原创粉丝点击
热门IT博客
淘宝联盟怎么提现?淘宝联盟怎么提现?
办公软件官方下载办公软件官方下载
linux 查看文件第一行
淘宝客推广渠道
推荐java培训学校
安卓数据恢复破解版apk
暴风影音软件
网络真人视频赌博揭秘
怎么利用网络看电视
有特效的编程软件
中信建投mac版下载
大数据产业的未来
街霸5网络功能已禁用
ios webview性能优化
国际化 数据库设计
言不由衷 徐佳莹 知乎
大班幼儿美工作品图片
python实现二叉树
matlab2015a破解版mac
linux ntp客户端配置
热门问题 老师的惩罚 人脸识别 我在镇武司摸鱼那些年 重生之率土为王 我在大康的咸鱼生活 盘龙之生命进化 天生仙种 凡人之先天五行 春回大明朝 姑娘不必设防，我是瞎子 唱歌上不去怎么办 遇到老婆出轨怎么办 怎么办吉他谱txt蒋山 怎么办布衣乐队吉他谱 没有你我怎么办 没有理想该怎么办 没有工作该怎么办 子宫肌腺病怎么办 子宫泉肌症该怎么办 我该怎么办,歌曲 美国总统死了怎么办 塔吊信号工证怎么办? 发财树皮软怎么办 家庭主妇离婚了怎么办 没工作该怎么办 弹钢琴翘手指怎么办 弹钢琴小拇指翘怎么办 上身很瘦腿很粗怎么办 月经稀少怎么办 腿粗怎么办 猫咪有口臭怎么办 猫咪口臭怎么办 嘴臭怎么办 小猫嘴巴臭怎么办 小猫嘴巴腥臭怎么办 嘴巴臭怎么办 口水臭怎么办 猫嘴巴丑怎么办 小猫有点口臭怎么办 猫咪得了口炎怎么办 金珉锡 你怎么办 怎么办我爱卞白贤汤圆 怎么办我爱你边伯贤 怎么办我爱你边伯贤78 怎么办我爱你边伯贤97 怎么办,我爱你小说 韩国软件限制怎么办 cad不能缩放怎么办 鼠标滚动不了怎么办 屁眼流血怎么办 骨骼变形怎么办

程序博客网，程序员的互联网技术博客家园。csdn论坛精品 msdn技术资料都在这里