universal image loader display images from SD card

Question

my goal is to display images(thumbnails) from SD card in smooth list so i edited the demo sample(loading images from web to gridview) a bit to load the images from SD card to see the performance , and when the images are not cached (first time) it's pretty slow since it should be loading the images from local SD card not the web, but after the images are cached iam pretty happy with the results,please take a look and let me know if iam doing anything wrong, or how can i increase performance at first loading, also iam open for other libraries that maybe more specialized in loading images form SD card,here is the code :-

public class ImageGridActivity extends AbsListViewBaseActivity {


    // get files path in camera folder
     public String[] getimages() {   
         String[] images=new String[175];
         String path="file:///mnt/sdcard/DCIM/Camera/";
         int counter=0;
          String name;
         File sdCardRoot = Environment.getExternalStorageDirectory();
         File yourDir = new File(sdCardRoot, "dcim/camera");
         for (File f : yourDir.listFiles()) {
             if (f.isFile()){
               name = path + f.getName().toString() ;
          images[counter]=name;
                 // make something with the name
             counter++;}
         }
         return images;
     }   



    String[] imageUrls= getimages();
    DisplayImageOptions options;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.ac_image_grid);



        Bundle bundle = getIntent().getExtras();
    //  imageUrls = bundle.getStringArray(Extra.IMAGES);
    //  imageUrls[0]="file:///mnt/sdcard/DCIM/Camera/abc.jpg";

        options = new DisplayImageOptions.Builder()
    /*      .showStubImage(R.drawable.ic_stub)
            .showImageForEmptyUri(R.drawable.ic_empty)
            .showImageOnFail(R.drawable.ic_error)
            .cacheInMemory(true)
            .cacheOnDisc(true)
            .bitmapConfig(Bitmap.Config.RGB_565)
            .build(); */
        .showStubImage(R.drawable.ic_stub)
        .showImageForEmptyUri(R.drawable.ic_empty)
        .imageScaleType(ImageScaleType.IN_SAMPLE_POWER_OF_2)
        .showImageOnFail(R.drawable.ic_launcher).cacheInMemory()
        .cacheOnDisc().bitmapConfig(Bitmap.Config.RGB_565).build();

        ImageLoaderConfiguration config = new ImageLoaderConfiguration.Builder(
                getApplicationContext()).discCacheExtraOptions(720  , 1280 , CompressFormat.PNG, 0, null).build();

        ImageLoader.getInstance().init(config);


        listView = (GridView) findViewById(R.id.gridview);
        ((GridView) listView).setAdapter(new ImageAdapter());
        listView.setOnItemClickListener(new OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                startImagePagerActivity(position);
            }
        });
    }

    private void startImagePagerActivity(int position) {
        Intent intent = new Intent(this, ImagePagerActivity.class);
        intent.putExtra(Extra.IMAGES, imageUrls);
        intent.putExtra(Extra.IMAGE_POSITION, position);
        startActivity(intent);
    }

    public class ImageAdapter extends BaseAdapter {


        @Override
        public int getCount() {
            return imageUrls.length;
        }

        @Override
        public Object getItem(int position) {
            return null;
        }

        @Override
        public long getItemId(int position) {
            return position;
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            final ImageView imageView;
            if (convertView == null) {
                imageView = (ImageView) getLayoutInflater().inflate(R.layout.item_grid_image, parent, false);
            } else {
                imageView = (ImageView) convertView;
            }

            imageLoader.displayImage(imageUrls[position], imageView, options);

            return imageView;
        }
    }
}

item_grid_image

<?xml version="1.0" encoding="utf-8"?>
<ImageView xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/image"
    android:layout_width="fill_parent"
    android:layout_height="120dip"
    android:adjustViewBounds="true"
    android:contentDescription="@string/descr_image"
    android:scaleType="centerCrop" />

thank you in advance,

Answer 1

First thing is that I would not initialize the image loader every time I pass through onCreate of your activity. Basically, you do not need more than one initialization so I suggest you initialize it in your Application onCreate. I do not know how the image loader will behave if you reinitialize it after it already started downloading some images.

Apart from that what you are doing seems a bit weird for me - you already have the images on your phone, but you give the image loader the task to take them and store them once more so that it has them cached. I think this parameter to your configuration is spurious: .cacheOnDisc() try doing without it and see if you get any faster (removing it will stop UIL from doing duplicate on SD card)