Image compression gives different size on different OS?

Question

I am capturing image from camera and onActivityResult(). I'm rescaling the image to 800 x 600 along with 70% compression factor. While I am doing so I am getting different image sizes for the same camera resolution.

Bitmap pic = BitmapFactory.decodeFile(myPath);
Bitmap bitmap = Bitmap.createScaledBitmap(pic, 800, 600, true);
OutputStream os = null;
File file = new File("MyFile.png");

try {
    os = new FileOutputStream(file);
    bitmap.compress(Bitmap.CompressFormat.JPEG,70,outputStream);
    os.flush();
    os.close();
    pic = null;

}catch (IOException e){ 
...
}

The data below is for 5 MP in both the cases but with different device having different android version. The output that i got was:

On GingerBread(2.3.3) the image size that got saved to the SDCard was 130 KB.

On JellyBean(4.2) the image size that got saved to the SDCard was 59.3 KB.

The compressibility, and hence resulting file size, depends on the image! — Ernest Friedman-Hill, Oct 14 '13 at 10:56
it not depends on OS, it depends on camera of that particular device. — Sagar Maiyad, Oct 14 '13 at 11:25
@ErnestFriedman-Hill is right. Imagine taking a picture of a black dot on a piece of paper, that can be compressed very heavily independent of resolution or OS because there isn't much information (variety, entropy, whatever) in the picture. — arynaq, Oct 14 '13 at 11:58
Thank you for the quick response but both the images are identical, so in that case the compression should be the same. Right? — CodeWarrior, Oct 14 '13 at 13:11
@Segi That idea crossed my mind so i checked that too but the resolution of the camera for 5 MP in both the cases was same, is there any other parameter of the camera that may cause this to happen? — CodeWarrior, Oct 14 '13 at 13:13

score 0 · Answer 1 · edited May 23 '17 at 12:28

I was also observing the same thing happening when I was saving a bitmap loaded from resources when compressed and saved leading to different sized files on different Android OS. It is a little different problem than the one asked in the question but may be it gives some insight.

"Maybe you get your bitmap from a resource, in which case the bitmap dimension will depend on the phone screen density". The reasoning was part of answer to the following question:

How to make Bitmap compress without change the bitmap size?

Image compression gives different size on different OS?

1 Answers1