Move emoji files from drawable-nodpi to internal storage cause performance problem

[missmess]

I'm tring to move all the emoji pngs from drawable-nodpi into internal storage, but when showing all of the emojis in a TextView, load emoji from the drawable-nodpi dir is near 10 times faster than loading from the internal storage. Here is my modified EmojiconSpan.java:

public Drawable getDrawable() {
        if (mDrawable == null) {
            try {
                // I want to load from the file path
                mDrawable = Drawable.createFromPath(mFilePath);
                // load from resource
                // mDrawable = mContext.getResources().getDrawable(mResourceId);
                mHeight = mSize;
                mWidth = mHeight * mDrawable.getIntrinsicWidth() / mDrawable.getIntrinsicHeight();
                mTop = (mTextSize - mHeight) / 2;
                mDrawable.setBounds(0, mTop, mWidth, mTop + mHeight);
            } catch (Exception e) {
                // swallow
            }
        }
        return mDrawable;
    }

I dont know why it happens? And how can I move emojis to internal storage and keep it load as fast as it was?

[missmess]

I want to reduce the apk size by remove the emojis(5.8M) from apk, and download background when app opened.