Android的JPEG为位图的大小=减少 [英] Android JPEG to Bitmap = reduction in size

问题描述

我发现后，我将我的JPEG文件为位图的大小几乎降低一半，这正常吗？我做这样的事情：

  = BMP1 BitmapFactory.de codeFILE（Environment.getExternalStorageDirectory（）
                            +/测试/测试+ System.currentTimeMillis的（）
                            +.JPG）;
    ByteArrayOutputStream流=新ByteArrayOutputStream（）;
    bmp1.com preSS（Bitmap.Com pressFormat.JPEG，100，流）;
    字节[]的字节数组= stream.toByteArray（）;
    的System.out.println（byteArray.length）;
 

解决方案

您code为解码JPEG成位图，然后重新COM $ P $再次pssing它成JPEG。重新玉米pression很可能被降低文件的大小，在也降低了图象的质量的费用。

Jpeg的COM pression（甚至在品质100）不是无损的。

I noticed that after I converted my jpeg file into a bitmap the size drops almost by half, is this normal? I doing something like this:

    bmp1 = BitmapFactory.decodeFile(Environment.getExternalStorageDirectory()
                            + "/Test/test" + System.currentTimeMillis()
                            + ".jpg");
    ByteArrayOutputStream stream = new ByteArrayOutputStream();
    bmp1.compress(Bitmap.CompressFormat.JPEG, 100, stream);
    byte[] byteArray = stream.toByteArray();
    System.out.println(byteArray.length);

解决方案

Your code is decoding a jpeg into a bitmap and then re-compressing it into a jpeg again. The re-compression is likely to be reducing the file size, at the cost of also reducing the quality of the image.

Jpeg compression (even at quality 100) is not lossless.

这篇关于Android的JPEG为位图的大小=减少的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！