There are so many comparations between Android phone and iPhone. We cannot make the conclusion about which one is better, but we all knows that the image quality of Android phone is much worse than iPhone. No matter you are using Facebook, Twitter or even Instagram, after taking the photo, adding a filter, then sharing to the social network, the images produced by Android phone are always coarse. Why?

Our team had been working on this issue in the last year. After very deep research, we found that this was a "TINY" mistake made by Google. Although tiny, but the influence was very huge (all Android Apps related to image), and lasted till today.

The problem is : libjpeg.

We all know that libjpeg is widely used open source JPEG library. Android also uses libjpeg to compress images. After digging into the source code of Android, we can find that instead of using libjpeg directly, Android is based on an open source image engine called Skia. The Skia is a wonderful engine maintained by Google himself, all image functions are implemented in it, and it is widely used by Google and other companies' products (e.g.: Chrome, Firefox, Android......). The Skia has a good encapsulation of libjpeg, you can easily develop image utilites base on this engine.

When using libjpeg to compress images, optimize_coding is a very important parameter. In libjpeg.