Java-Android-在一部手机上压缩位图的速度非常慢,在另一部手机上的压缩速度非常快

2023-08-07 22:37:10

我正在编写一个具有简单摄像头功能的应用程序.我在主要活动中拍照,然后启动一个新线程以旋转图像,添加透明水印并将其另存为.PNG.

这个程序在运行自定义rom的三星银河S3上运行良好：AOKP,Android 4.4.2.下面给出的代码执行总时间约为2秒.根据任务管理器,我的应用程序使用了大约9 Mb的内存.

当我在运行有库存(有根)的Android 4.4.2的银河S4上运行该应用程序时,执行时间超过了27秒.该应用程序根据任务管理器使用大约124 Mb的内存(太多).有时,应用程序崩溃并抛出OutOfMemory错误,这在S3上不会发生.

这是负责将图像保存到我的SaveThread中的代码：

            TimingLogger tl = new TimingLogger("MyTag", "Saving");            
            String name = new SimpleDateFormat("dd-MM-yyyy_HH-mm-ss")
                    .format(new Date());
            File myNewFolder = new File(path);
            myNewFolder.mkdir();
            File file = new File(path, name + ".JPEG");
            OutputStream imageFileOS;

            // Get EXIF rotation from byte array
            int rotation = getOrientation(data);
            tl.addSplit("Rotation calculated");
            // Convert byte array to bitmap, and watermark bitmap
            Bitmap pictureObject = BitmapFactory.decodeByteArray(data, 0,
                    data.length);
            tl.addSplit("Decoded ByteArray to Bitmap");

            // Rotate bitmap image according to EXIF data
            pictureObject = rotateBitmap(rotation, pictureObject);
            tl.addSplit("Bitmap rotated");
            // Add watermark to rotated bitmap
            Bitmap waterMarkedBitmap = addWaterMarkText(pictureObject);
            tl.addSplit("Bitmap watermarked");
            try {
                imageFileOS = new FileOutputStream(file);
                waterMarkedBitmap.compress(Bitmap.CompressFormat.PNG, 100,
                        imageFileOS);
                tl.addSplit("Bitmap compressed");
                imageFileOS.flush();
                imageFileOS.close();
            } catch (Exception e) {
                e.printStackTrace();
            }

如您所见,我添加了一个计时记录器来找出花费这么长时间的时间.下面的LogCat返回结果表明,将位图压缩为.PNG需要很长时间.我认为这可能与垃圾收集器有关.我的Logcat在执行期间返回以下内容：

        02-04 13:57:08.166: I/Choreographer(30003): Skipped 73 frames!  The
        application may be doing too much work on its main thread.
        02-04 13:57:10.528: D/dalvikvm(30003): GC_FOR_ALLOC freed 552K, 19% free 24803K/30324K, paused 48ms, total 49ms
        02-04 13:57:10.628: I/dalvikvm-heap(30003): Grow heap (frag case) to 76.336MB for 51121168-byte allocation
        02-04 13:57:10.918: D/dalvikvm(30003): GC_FOR_ALLOC freed 4K, 7% free 74723K/80248K, paused 23ms, total 23ms
        02-04 13:57:11.019: I/dalvikvm-heap(30003): Grow heap (frag case) to 125.086MB for 51121168-byte allocation
        02-04 13:57:11.859: D/dalvikvm(30003): GC_FOR_ALLOC freed 49923K, 43% free 74723K/130172K, paused 25ms, total 26ms
        02-04 13:57:11.869: I/dalvikvm-heap(30003): Grow heap (frag case) to 125.086MB for 51121168-byte allocation
        02-04 13:57:39.967: D/MyTag(30003): Saving: begin
        02-04 13:57:39.967: D/MyTag(30003): Saving:      3 ms, Rotation calculated
        02-04 13:57:39.967: D/MyTag(30003): Saving:      418 ms, Decoded ByteArray to Bitmap
        02-04 13:57:39.967: D/MediaScannerConnection(30003): Scanning file 7klwibgf7fvntblfd7(7KhzCbvfib7(,6()6)(*._*+6./6*(5QHFG
        02-04 13:57:39.967: D/MyTag(30003): Saving:      939 ms, Bitmap rotated
        02-04 13:57:39.967: D/MyTag(30003): Saving:      96 ms, Bitmap watermarked
        02-04 13:57:39.967: D/MyTag(30003): Saving:      28023 ms, Bitmap compressed
        02-04 13:57:39.967: D/MyTag(30003): Saving:      0 ms, Done saving
        02-04 13:57:39.967: D/MyTag(30003): Saving:      8 ms, Media scanned
        02-04 13:57:39.967: D/MyTag(30003): Saving: end, 29487 ms

我不确定是否相关,但LogCat行：

D/MediaScannerConnection(30003): Scanning file 7klwibgf7fvntblfd7(7KhzCbvfib7(,6()6)(*._*+6./6*(5QHFG

显然不会显示扫描文件的路径(尽管它确实可以工作).当我将S3连接到Eclipse时,此行会显示扫描的文件路径.

我尝试更改压缩质量,但是并没有在速度或内存使用方面做出重大改变.我不知道是什么原因导致了RAM使用率和执行时间的巨大差异.是什么会导致这种差异,我该如何解决？

编辑：完整地说,这就是在银河S3上压缩的速度：

02-04 15:40:47.980: D/MyTag(25536): Saving:      6 ms, Rotation calculated
02-04 15:40:47.980: D/MyTag(25536): Saving:      53 ms, Decoded ByteArray to Bitmap
02-04 15:40:47.980: D/MyTag(25536): Saving:      94 ms, Bitmap rotated
02-04 15:40:47.980: D/MyTag(25536): Saving:      19 ms, Bitmap watermarked
02-04 15:40:47.980: D/MyTag(25536): Saving:      210 ms, Bitmap compressed
02-04 15:40:47.980: D/MyTag(25536): Saving:      0 ms, Done saving
02-04 15:40:47.980: D/MyTag(25536): Saving:      3 ms, Media scanned
02-04 15:40:47.980: D/MyTag(25536): Saving: end, 385 ms

当我在S3上使用前置摄像头拍摄照片时,压缩时间要长得多(我真的不知道为什么…)：

02-04 20:24:31.245: D/MyTag(29496): Saving: begin
02-04 20:24:31.245: D/MyTag(29496): Saving:      2 ms, Rotation calculated
02-04 20:24:31.245: D/MyTag(29496): Saving:      95 ms, Decoded ByteArray to Bitmap
02-04 20:24:31.245: D/MyTag(29496): Saving:      160 ms, Bitmap rotated
02-04 20:24:31.245: D/MyTag(29496): Saving:      25 ms, Bitmap watermarked
02-04 20:24:31.245: D/MyTag(29496): Saving:      4548 ms, Bitmap compressed
02-04 20:24:31.245: D/MyTag(29496): Saving:      0 ms, Done saving
02-04 20:24:31.245: D/MyTag(29496): Saving:      3 ms, Media scanned
02-04 20:24:31.245: D/MyTag(29496): Saving: end, 4833 ms

解决方法:

我想到了.我犯了一个非常愚蠢的错误.我正在压缩为.PNG,但另存为.JPEG,这显然是某些设备的问题.现在压缩3096×4128图像需要2秒钟,我认为这是正常的(100％).

虽然这不能解决所有问题.该代码仍然在S4上使用超过100 Mb,并且有时仍会引发OutOfMemory错误.该代码可在S3上完美运行.

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