Bitmap

圖片原始像素大小爲2268X4032 佔用硬盤空間爲3.94MB

解析圖片尺寸        
BitmapFactory.Options opt = new BitmapFactory.Options();
        opt.inJustDecodeBounds = true;
        Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.raw.iii, opt);
        Log.e("iffy", "opt.outWidth" + opt.outWidth);
        Log.e("iffy", "opt.outHeight" + opt.outHeight);
        Log.e("iffy", "opt.inPreferredConfig" + opt.inPreferredConfig);
        Log.e("iffy", "縮放前大小" + opt.outWidth+"*"+opt.outHeight+"* ARGB_8888(4)/1024="+opt.outWidth*opt.outHeight*4/1024/1024+"M");

 

 

計算採樣值

opt.inSampleSize = calculateInSampleSize(opt, 500, 500);
        Log.e("iffy", "opt.inSampleSize" + opt.inSampleSize);

        opt.inJustDecodeBounds = false;
        Bitmap bm = BitmapFactory.decodeResource(getResources(), R.raw.iii, opt);
        Log.e("iffy", "bm.getWidth()" + bm.getWidth());
        Log.e("iffy", "bm.getHeight()" + bm.getHeight());
        Log.e("iffy", "縮放後大小" + bm.getWidth()+"*"+bm.getHeight()+"* ARGB_8888(4)/1024="+bm.getWidth()*bm.getHeight()*4/1024/1024+"M");

讓imageview顯示

        ImageView imgView = findViewById(R.id.img);
        imgView.setImageBitmap(bm);

Dump信息

查看內存情況

1.查看Bitmap大小

2.查看Bitmap實際佔用空間15Mb和logcat計算的大小一致

3.查看bitmap長寬