Luban—Image compression with efficiency very close to WeChat Moments

郑梓斌

Last update: Dec 29, 2022

Overview

Luban

📖 English Documentation

Luban（鲁班） —— Android图片压缩工具，仿微信朋友圈压缩策略。

Luban-turbo —— 鲁班项目的turbo版本，查看trubo分支。

写在前面

家境贫寒，工作繁忙。只能不定期更新，还望网友们见谅！

项目描述

目前做App开发总绕不开图片这个元素。但是随着手机拍照分辨率的提升，图片的压缩成为一个很重要的问题。单纯对图片进行裁切，压缩已经有很多文章介绍。但是裁切成多少，压缩成多少却很难控制好，裁切过头图片太小，质量压缩过头则显示效果太差。

于是自然想到App巨头“微信”会是怎么处理，Luban（鲁班）就是通过在微信朋友圈发送近100张不同分辨率图片，对比原图与微信压缩后的图片逆向推算出来的压缩算法。

因为有其他语言也想要实现Luban，所以描述了一遍算法步骤。

因为是逆向推算，效果还没法跟微信一模一样，但是已经很接近微信朋友圈压缩后的效果，具体看以下对比！

效果与对比

内容	原图	`Luban`	`Wechat`
截屏 720P	720*1280,390k	720*1280,87k	720*1280,56k
截屏 1080P	1080*1920,2.21M	1080*1920,104k	1080*1920,112k
拍照 13M(4:3)	3096*4128,3.12M	1548*2064,141k	1548*2064,147k
拍照 9.6M(16:9)	4128*2322,4.64M	1032*581,97k	1032*581,74k
滚动截屏	1080*6433,1.56M	1080*6433,351k	1080*6433,482k

导入

implementation 'top.zibin:Luban:1.1.8'

使用

方法列表

方法	描述
load	传入原图
filter	设置开启压缩条件
ignoreBy	不压缩的阈值，单位为K
setFocusAlpha	设置是否保留透明通道
setTargetDir	缓存压缩图片路径
setCompressListener	压缩回调接口
setRenameListener	压缩前重命名接口

异步调用

Luban内部采用IO线程进行图片压缩，外部调用只需设置好结果监听即可：

Luban.with(this)
        .load(photos)
        .ignoreBy(100)
        .setTargetDir(getPath())
        .filter(new CompressionPredicate() {
          @Override
          public boolean apply(String path) {
            return !(TextUtils.isEmpty(path) || path.toLowerCase().endsWith(".gif"));
          }
        })
        .setCompressListener(new OnCompressListener() {
          @Override
          public void onStart() {
            // TODO 压缩开始前调用，可以在方法内启动 loading UI
          }

          @Override
          public void onSuccess(File file) {
            // TODO 压缩成功后调用，返回压缩后的图片文件
          }

          @Override
          public void onError(Throwable e) {
            // TODO 当压缩过程出现问题时调用
          }
        }).launch();

同步调用

同步方法请尽量避免在主线程调用以免阻塞主线程，下面以rxJava调用为例

Flowable.just(photos)
    .observeOn(Schedulers.io())
    .map(new Function<List<String>, List<File>>() {
      @Override public List<File> apply(@NonNull List<String> list) throws Exception {
        // 同步方法直接返回压缩后的文件
        return Luban.with(MainActivity.this).load(list).get();
      }
    })
    .observeOn(AndroidSchedulers.mainThread())
    .subscribe();

RELEASE NOTE

Here

License

Copyright 2016 Zheng Zibin

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.

Comments

讨论帖，新需求与新想法集中营

您这个是图片上传的时候，本地图片压缩吗？我之前也研究过微信朋友圈的图片压缩，当时得到的结果是：第一步进行采样率压缩；第二步进行宽高的等比例压缩（微信对原图和缩略图限制了最大长宽或者最小长宽）；第三步就是对图片的质量进行压缩（一般75或者70）；第四部就是采用webP的格式。经过这四部的处理，基本上和微信朋友圈的效果一致，包括文件大小和显示效果。（PS：最近看到微信朋友圈好像换了图片格式，这还有待考证）

opened by wo327808864 18
批量压缩有问题
for (int i = 0; i < activity.selectedImgList.size(); i++) { final ImageItem img = activity.selectedImgList.get(i); if (img.size / 1024 < 500) { /*不压缩直接添加*/ compressedImgList.add(new File(img.path)); checkComplete(); } else { /*压缩后再添加*/ compressImg(new File(img.path), i); } }

上面是添加压缩任务

然后开始压缩，结果 compressedImgList.add(file);的时候添加的是重复的图片 private void compressImg(final File imgFile, int position) { L.i("压缩图片"); Luban.get(activity) .load(imgFile) .putGear(Luban.THIRD_GEAR) .setFilename(imgFile.getName()) .setCompressListener(new OnCompressListener() { @Override public void onStart() {

Log.i("开始压缩,原图大小：", imgFile.length() / 1024 + "k"); } @Override public void onSuccess(File file) { Log.i("压缩完成，压缩后大小：", file.length() / 1024 + "k"); compressedImgList.add(file); L.i("添加的文件名是：" + file.getName()); checkComplete(); } @Override public void onError(Throwable e) { /*压缩失败添加原图*/ L.i("压缩失败添加原图"); compressedImgList.add(imgFile); checkComplete(); } }).launch(); }

下面是打印日志

I/压缩完成，压缩后大小：: 191k 10-27 15:02:26.023 28680-28680/com.ship.yzq.ship I/shipApp: 添加的文件名是：IMG_20161027_142337.jpg.jpg 10-27 15:02:26.605 28680-28680/com.ship.yzq.ship I/压缩完成，压缩后大小：: 178k 10-27 15:02:26.606 28680-28680/com.ship.yzq.ship I/shipApp: 添加的文件名是：IMG_20161027_142331.jpg.jpg 10-27 15:02:26.682 28680-28680/com.ship.yzq.ship I/压缩完成，压缩后大小：: 184k 10-27 15:02:26.682 28680-28680/com.ship.yzq.ship I/shipApp: 添加的文件名是：IMG_20161027_142331.jpg.jpg 10-27 15:02:26.781 28680-28680/com.ship.yzq.ship I/压缩完成，压缩后大小：: 189k 10-27 15:02:26.781 28680-28680/com.ship.yzq.ship I/shipApp: 添加的文件名是：IMG_20161027_142327.jpg.jpg 10-27 15:02:26.807 28680-28680/com.ship.yzq.ship I/shipApp: IMG_20161027_142337.jpg.jpg 10-27 15:02:26.807 28680-28680/com.ship.yzq.ship I/shipApp: IMG_20161027_142331.jpg.jpg 10-27 15:02:26.807 28680-28680/com.ship.yzq.ship I/shipApp: IMG_20161027_142331.jpg.jpg 10-27 15:02:26.807 28680-28680/com.ship.yzq.ship I/shipApp: IMG_20161027_142327.jpg.jpg
opened by yuzhiqiang1993 9
Luban 压缩后得到的文件路径问题

Luban.get(getContext()) .load(new File(item.path)) //传人要压缩的图片 .putGear(Luban.THIRD_GEAR) //设定压缩档次，默认三挡 .setFilename(SDCardUtils.SdPath(getContext(), "qa") + System.currentTimeMillis() + "." + FileUtils.getFilenameExtension(item.path))

为了在压缩后有时是没有后缀,所以设置文件路径名称,使其压缩后按该文件路径跟名称保存. 但是,目前情况是得到的文件结果不可预料...有时候是按设置的路径名称,有时候是原路径,设置的没有起作用.对于该方法到底是起到一个什么作用疑惑.我就是想压缩后按我给的路径生成文件,希望能给出具体的解决方案.

opened by BloodBamboo 6
小公告

1、我最近在找工作，Luban 也是这两天突然爆发起来，如果有问题请各位包涵 2、图片压缩是安卓开发的刚需，我希望能靠大家一起讨论完善 Luban 3、如果想把 Luban 用上线上产品的大大请直接用源码，并针对自家产品优化，不要因为 Luban 而对产品造成影响 4、我会不断花时间优化 Luban 项目，希望大家多多支持 5、想加入讨论的大家是希望建Q群，微信群，还是继续在 issues 中讨论，可以在本 issues 下发表意见

opened by Curzibn 6

好像是导致不清晰的原因

213, 214 行 width 和 height 转变成了最短边和最长边

        width = thumbW > thumbH ? thumbH : thumbW;
        height = thumbW > thumbH ? thumbW : thumbH;

可是后面有用它来当做宽高来计算 (取名字多么重要)

   thumbW = width / 2;
   thumbH = height / 2;

   thumbW = width / 4;
    thumbH = height / 4;

是不是想写 ?

thumbW/=2;

opened by u787i 5

循环压缩图片可能会把压缩的图片输出在相同的文件地址导致覆盖

rt,我是这么循环压缩的

for(String fileUrl : fileList){
            Luban.get(this).putGear(Luban.THIRD_GEAR)
            .load(new File(fileUrl))
//            .setFilename(getCurrentPhotoFile().getAbsolutePath())
            .setCompressListener(new OnCompressListener() {

                @Override
                public void onSuccess(File file) {
                    DLog.i("完成剪裁:" + file.getAbsolutePath());
                    mCompressList.add(file.getAbsolutePath());
                    if(mCompressList.size() == fileList.size()){
                        uploadFile(mCompressList);
                    }
                }

                @Override
                public void onStart() {
                    DLog.i("开始剪裁");
                }

                @Override
                public void onError(Throwable e) {
                    DLog.i("error:" + e.toString());
                }
            }).launch();

结果发现剪裁完的地址可能会出现相同的结果。

opened by Baifann 5

java.lang.NoClassDefFoundError: Failed resolution of: Lrx/Observable;
public void dealImg(ArrayList fileList){ files.clear(); for (int i = 0; i < fileList.size(); i++) { File file = fileList.get(i); Luban.get(this) .load(file) //传人要压缩的图片 .putGear(Luban.THIRD_GEAR) //设定压缩档次，默认三挡 .setCompressListener(new OnCompressListener() { @Override public void onStart() {

} @Override public void onSuccess(File file) { files.add(file); } public void onError(Throwable e) { } }).launch(); //启动压缩 } }

java.lang.NoClassDefFoundError: Failed resolution of: Lrx/Observable; at top.zibin.luban.Luban.launch(Luban.java:113) at com.xinji.jugongyouyue.workeractivity.WorkerActivityAddProject.dealImg(WorkerActivityAddProject.java:304) at com.xinji.jugongyouyue.workeractivity.WorkerActivityAddProject.onActivityResult(WorkerActivityAddProject.java:296) at android.app.Activity.dispatchActivityResult(Activity.java:6378) at android.app.ActivityThread.deliverResults(ActivityThread.java:3970) at android.app.ActivityThread.handleSendResult(ActivityThread.java:4017) at android.app.ActivityThread.access$1300(ActivityThread.java:178) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1602) at android.os.Handler.dispatchMessage(Handler.java:111) at android.os.Looper.loop(Looper.java:192) at android.app.ActivityThread.main(ActivityThread.java:5784) at java.lang.reflect.Method.invoke(Native Method) at java.lang.reflect.Method.invoke(Method.java:372) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1084) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:850) Caused by: java.lang.ClassNotFoundException: Didn't find class "rx.Observable" on path: DexPathList[[zip file "/data/app/com.xinji.jugongyouyue-1/base.apk"],nativeLibraryDirectories=[/data/app/com.xinji.jugongyouyue-1/lib/arm, /vendor/lib, /system/lib]] at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:56) at java.lang.ClassLoader.loadClass(ClassLoader.java:511) at java.lang.ClassLoader.loadClass(ClassLoader.java:469) at top.zibin.luban.Luban.launch(Luban.java:113) at com.xinji.jugongyouyue.workeractivity.WorkerActivityAddProject.dealImg(WorkerActivityAddProject.java:304) at com.xinji.jugongyouyue.workeractivity.WorkerActivityAddProject.onActivityResult(WorkerActivityAddProject.java:296) at android.app.Activity.dispatchActivityResult(Activity.java:6378) at android.app.ActivityThread.deliverResults(ActivityThread.java:3970) at android.app.ActivityThread.handleSendResult(ActivityThread.java:4017) at android.app.ActivityThread.access$1300(ActivityThread.java:178) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1602) at android.os.Handler.dispatchMessage(Handler.java:111) at android.os.Looper.loop(Looper.java:192) at android.app.ActivityThread.main(ActivityThread.java:5784) at java.lang.reflect.Method.invoke(Native Method) at java.lang.reflect.Method.invoke(Method.java:372) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1084) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:850) Suppressed: java.lang.ClassNotFoundException: rx.Observable at java.lang.Class.classForName(Native Method) at java.lang.BootClassLoader.findClass(ClassLoader.java:781) at java.lang.BootClassLoader.loadClass(ClassLoader.java:841) at java.lang.ClassLoader.loadClass(ClassLoader.java:504) ... 16 more
opened by andansky 5
Engine.compress(Engine.java:79) this line throws java.lang.NullPointerException,please fixed.thx

日志如下：

Attempt to invoke virtual method 'boolean android.graphics.Bitmap.compress(android.graphics.Bitmap$CompressFormat, int, java.io.OutputStream)' on a null object reference

top.zibin.luban.Engine.compress(Engine.java:79)

opened by steven-gao 4
java.lang.NoSuchFieldException

e.e.d.b.an.a(UnsafeAccess.java:109) 3 ...... 4 Caused by: 5 java.lang.NoSuchFieldException:producerIndex 6 java.lang.Class.getDeclaredField(Class.java:596) 7 e.e.d.b.an.a(UnsafeAccess.java:106) 8 e.e.d.b.n.(MpmcArrayQueue.java:31) 9 e.e.d.j.a(ObjectPool.java:153) 10 e.e.d.j.(ObjectPool.java:57) 11 e.e.d.j.(ObjectPool.java:36) 12 e.e.d.o$1.(RxRingBuffer.java:280) 13 e.e.d.o.(RxRingBuffer.java:280) 14 e.d.a(Observable.java:6394) 15 top.zibin.luban.b.a(Luban.java:135)

是什么问题啊？

opened by shenminjie 4

压缩时一直loading，且有不小的概率会Crash

华为mate30Pro，鸿蒙系统 v3.10.6 已经设置targetSdk = 29和android:requestLegacyExternalStorage="true"

public class ImageCompressEngine implements CompressFileEngine {

    @Override
    public void onStartCompress(Context context, ArrayList<Uri> source, OnKeyValueResultCallbackListener call) {
        Luban.with(context).load(source).ignoreBy(500)
                .filter(path -> PictureMimeType.isUrlHasImage(path) && !PictureMimeType.isHasHttp(path))
                .setCompressListener(new OnNewCompressListener() {
                    @Override
                    public void onStart() {

                    }

                    @Override
                    public void onSuccess(String source, File compressFile) {
                        LogUtils.i("localMediaCompress",source);
                        if (call != null) {
                            call.onCallback(source, compressFile.getAbsolutePath());
                        }
                    }

                    @Override
                    public void onError(String source, Throwable e) {
                        LogUtils.i("localMediaCompress", source);
                        LogUtils.i("localMediaCompress", e.getMessage());
                        if (call != null) {
                            call.onCallback(source, null);
                        }
                    }
                }).launch();
    }
}

稍微大点的图片，2-3M的，手机拍照的，就会loading很长时间，一张差不多2分钟左右吧，且大几率会crash

opened by jerry9433 3

android.graphics.Bitmap.compres()方法在安卓11上代码执行报错

执行代码：Luban.with(context).load(fileList).get(); 运行设备：荣耀magic ui 安卓11设备上报错，小米安卓12上代码正常执行报错信息： Attempt to invoke virtual method 'boolean android.graphics.Bitmap.compress(android.graphics.Bitmap$CompressFormat, int, java.io.OutputStream)' on a null object reference

opened by pigMan15 1

android Q适配

android Q上若传文件Uri，使用Uri类型的InputStreamProvider

new InputStreamProvider() {
@Override
                public InputStream open() throws IOException {
                    return context.getContentResolver().openInputStream(uri);
                }

                @Override
                public String getPath() {
                    return uri.getPath();
                }

                @Override
                public boolean isUri() {
                    return true;
                }

                @Override
                public long getLength() {
                    try {
                        switch (uri.getScheme()) {
                            case ContentResolver.SCHEME_FILE:
                                return new File(uri.getPath()).length();
                            case ContentResolver.SCHEME_CONTENT:
                                Cursor cursor = context.getContentResolver().query(uri, null, null, null, null);
                                long tempLength = 0;
                                if (cursor != null && cursor.moveToFirst()) {
                                    tempLength = new File(cursor.getString(cursor.getColumnIndex("_data"))).length();
                                    cursor.close();
                                }
                                return tempLength;
                        }
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                    return 0;
                }
            }

在原Luban compress方法中

private File compress(Context context, InputStreamProvider path) throws IOException {
        File result;

        File outFile = getImageCacheFile(context, Checker.SINGLE.extSuffix(path));

        if (mRenameListener != null) {
            String filename = mRenameListener.rename(path.getPath());
            outFile = getImageCustomFile(context, filename);
        }

        if (mCompressionPredicate != null) {
            if (mCompressionPredicate.apply(path.getPath())
                    && Checker.SINGLE.needCompress(mLeastCompressSize, path)) {
                result = new Engine(path, outFile, focusAlpha).compress();
            } else {
                result = new File(path.getPath());
            }
        } else {
            result = Checker.SINGLE.needCompress(mLeastCompressSize, path) ?
                    new Engine(path, outFile, focusAlpha).compress() :
                    new File(path.getPath());
        }

        return result;
    }

若Checker.SINGLE.needCompress()返回false，直接返回uri.getPath() = eg：/external/images/media/1947 这个路径是公共目录，不能直接通过uri访问但通过根据InputStreamProvider的open方法返回的InputStream，可以获取到源文件数据，copy到私有目录即可

private File compress(Context context, InputStreamProvider path) throws IOException {
        File result;

        File outFile = getImageCacheFile(context, Checker.SINGLE.extSuffix(path));

        if (mRenameListener != null) {
            String filename = mRenameListener.rename(path.getPath());
            outFile = getImageCustomFile(context, filename);
        }

        if (mCompressionPredicate != null) {
            if (mCompressionPredicate.apply(path.getPath())
                    && Checker.SINGLE.needCompress(mLeastCompressSize, path)) {
                result = new Engine(path, outFile, focusAlpha).compress();
            } else {
                // android Q后拷贝文件到私有目录
                result = path.isUri() ? new Mold(path, outFile).copy() : new File(path.getPath());
            }
        } else {
            result = Checker.SINGLE.needCompress(mLeastCompressSize, path) ?
                    new Engine(path, outFile, focusAlpha).compress() :
                    // android Q后拷贝文件到私有目录
                    (path.isUri() ? new Mold(path, outFile).copy() : new File(path.getPath()));
        }

        return result;
    }

/**

copy file */

class Mold {
    private InputStreamProvider srcImg;
    private File tagImg;

    Mold(InputStreamProvider srcImg, File tagImg) {
        this.tagImg = tagImg;
        this.srcImg = srcImg;
    }

    File copy() throws IOException {
        InputStream inputStream = srcImg.open();
        FileOutputStream fos = new FileOutputStream(tagImg);
        byte[] b = new byte[1024];
        while ((inputStream.read(b)) != -1) {
            fos.write(b);// 写入数据
        }
        inputStream.close();
        fos.flush();
        fos.close();
        return tagImg;
    }
}

opened by yongshengdev 0

Improve GRADLE build Performance

Parallel test execution maxParallelForks. Gradle can run multiple test cases in parallel by setting maxParallelForks.

Disable report generation. We can conditionally disable it by setting reports.html.required = false; reports.junitXml.required = false. If you need to generate reports, add -PcreateReports to the end of Gradle's build command line.

===================== If there are any inappropriate modifications in this PR, please give me a reply and I will change them.

opened by shisheng-1 0

Releases(turbo-1.0.0)

turbo-1.0.0(Jul 23, 2018)

use libjpeg-turbo
Source code(tar.gz)
Source code(zip)
1.1.8(Jul 17, 2018)

fix bug that the method extSuffix() was sometimes OOM
Source code(tar.gz)
Source code(zip)
1.1.7(Jun 22, 2018)

fix some bug like StringIndexOutOfBoundsException
Source code(tar.gz)
Source code(zip)
1.1.6(Jun 20, 2018)
去除 ExifInterface 依赖

新增是否保留 png 图片的 alpha 通道功能（保留通道压缩缓慢，不保留透明部分会被黑色背景代替）

Source code(tar.gz)
Source code(zip)
1.1.5(Jun 20, 2018)
添加压缩前重命名接口

Source code(tar.gz)
Source code(zip)
1.1.4(Jun 19, 2018)
load 方法新增传入类型用以兼容 Uri、InputStream。

新增 filter 方法在图片压缩做判断是否需要压缩

Source code(tar.gz)
Source code(zip)