title: Getting blur images in Image View Android
body: <p>I am getting images from server, images are large in size, I am displaying them in thumbnail manner in my app, but the images look like compressed and blur.
  I am downloading them using lazy list method.</p>
  
  <p><img src="https://i.stack.imgur.com/uH7Os.png" alt="enter image description here"></p>
  
  <p>I have used Gallery and created its custom array adapter to show images.</p>
  
  <p>Here is the XML of Gallery item</p>
  
  <pre><code> &lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_marginLeft="20dp"
      android:layout_marginRight="20dp"
      android:background="@drawable/galimagebg"
      android:gravity="center_vertical|center_horizontal"
      android:orientation="vertical" &gt;
  
      &lt;ImageView
          android:id="@+id/ivGal"
          android:layout_width="250dp"
          android:layout_height="200dp"
          android:layout_margin="10dp"
           /&gt;
  
  &lt;/LinearLayout&gt;
  </code></pre>
  
  <p>LAZY LIST VIEW CODE (the class which is doing the work)</p>
  
  <pre><code>package imageutil;
  
  import java.io.File;
  import java.io.FileInputStream;
  import java.io.FileNotFoundException;
  import java.io.FileOutputStream;
  import java.io.InputStream;
  import java.io.OutputStream;
  import java.net.HttpURLConnection;
  import java.net.URL;
  import java.util.Collections;
  import java.util.Map;
  import java.util.Stack;
  import java.util.WeakHashMap;
  
  import android.app.Activity;
  import android.graphics.Bitmap;
  import android.graphics.BitmapFactory;
  import android.graphics.drawable.BitmapDrawable;
  import android.graphics.drawable.Drawable;
  import android.widget.ImageView;
  
  
  
  
  
  public class ImageLoader {
  
      MemoryCache memoryCache=new MemoryCache();
      FileCache fileCache;
      private Map&lt;ImageView, String&gt; imageViews=Collections.synchronizedMap(new WeakHashMap&lt;ImageView, String&gt;());
  
      Activity activity;
      public ImageLoader(Activity activity){
          //Make the background thead low priority. This way it will not affect the UI performance
          photoLoaderThread.setPriority(Thread.NORM_PRIORITY-1);
  
          fileCache=new FileCache(activity);
          this.activity = activity;
      }
  
      final int stub_id=R.drawable.loading;
      public void DisplayImage(String url, Activity activity, ImageView imageView)
      {
          imageViews.put(imageView, url);
          Bitmap bitmap=memoryCache.get(url);
          if(bitmap!=null)
          {
              //          imageView.setImageBitmap(bitmap);
              Drawable drawable = new  BitmapDrawable(bitmap);
              //          imageView.setBackgroundDrawable(drawable);
              imageView.setImageDrawable(drawable);
              //          imageView.setScaleType(ScaleType.CENTER);
          }
          else
          {
              queuePhoto(url, activity, imageView);
              imageView.setImageResource(stub_id);
          }    
      }
  
      private void queuePhoto(String url, Activity activity, ImageView imageView)
      {
          //This ImageView may be used for other images before. So there may be some old tasks in the queue. We need to discard them. 
          photosQueue.Clean(imageView);
          PhotoToLoad p=new PhotoToLoad(url, imageView);
          synchronized(photosQueue.photosToLoad){
              photosQueue.photosToLoad.push(p);
              photosQueue.photosToLoad.notifyAll();
          }
  
          //start thread if it's not started yet
          if(photoLoaderThread.getState()==Thread.State.NEW)
              photoLoaderThread.start();
      }
  
      private Bitmap getBitmap(String url) 
      {
          File f=fileCache.getFile(url);
  
          //from SD cache
          Bitmap b = decodeFile(f);
          if(b!=null)
              return b;
  
          //from web
          try {
              Bitmap bitmap=null;
              URL imageUrl = new URL(url);
              HttpURLConnection conn = (HttpURLConnection)imageUrl.openConnection();
              conn.setConnectTimeout(30000);
              conn.setReadTimeout(30000);
              InputStream is=conn.getInputStream();
              OutputStream os = new FileOutputStream(f);
              Utils.CopyStream(is, os);
              os.close();
              bitmap = decodeFile(f);
              return bitmap;
          } catch (Exception ex){
              ex.printStackTrace();
              return null;
          }
      }
  
      //decodes image and scales it to reduce memory consumption
      private Bitmap decodeFile(File f){
          try {
              //decode image size
              BitmapFactory.Options o = new BitmapFactory.Options();
              o.inJustDecodeBounds = true;
              BitmapFactory.decodeStream(new FileInputStream(f),null,o);
  
              //Find the correct scale value. It should be the power of 2.
              final int REQUIRED_SIZE=70;
              int width_tmp=o.outWidth, height_tmp=o.outHeight;
              int scale=1;
              while(true){
                  if(width_tmp/2&lt;REQUIRED_SIZE || height_tmp/2&lt;REQUIRED_SIZE)
                      break;
                  width_tmp/=2;
                  height_tmp/=2;
                  scale*=2;
              }
  
              //decode with inSampleSize
              BitmapFactory.Options o2 = new BitmapFactory.Options();
              o2.inSampleSize=scale;
              return BitmapFactory.decodeStream(new FileInputStream(f), null, o2);
          } catch (FileNotFoundException e) {}
          return null;
      }
  
      //Task for the queue
      private class PhotoToLoad
      {
          public String url;
          public ImageView imageView;
          public PhotoToLoad(String u, ImageView i){
              url=u; 
              imageView=i;
          }
      }
  
      PhotosQueue photosQueue=new PhotosQueue();
  
      public void stopThread()
      {
          photoLoaderThread.interrupt();
      }
  
      //stores list of photos to download
      class PhotosQueue
      {
          private Stack&lt;PhotoToLoad&gt; photosToLoad=new Stack&lt;PhotoToLoad&gt;();
  
          //removes all instances of this ImageView
          public void Clean(ImageView image)
          {
              for(int j=0 ;j&lt;photosToLoad.size();){
                  if(photosToLoad.get(j).imageView==image)
                      photosToLoad.remove(j);
                  else
                      ++j;
              }
          }
      }
  
      class PhotosLoader extends Thread {
          public void run() {
              try {
                  while(true)
                  {
                      //thread waits until there are any images to load in the queue
                      if(photosQueue.photosToLoad.size()==0)
                          synchronized(photosQueue.photosToLoad){
                              photosQueue.photosToLoad.wait();
                          }
                      if(photosQueue.photosToLoad.size()!=0)
                      {
                          PhotoToLoad photoToLoad;
                          synchronized(photosQueue.photosToLoad){
                              photoToLoad=photosQueue.photosToLoad.pop();
                          }
                          Bitmap bmp=getBitmap(photoToLoad.url);
                          memoryCache.put(photoToLoad.url, bmp);
                          String tag=imageViews.get(photoToLoad.imageView);
                          if(tag!=null &amp;&amp; tag.equals(photoToLoad.url)){
                              BitmapDisplayer bd=new BitmapDisplayer(bmp, photoToLoad.imageView);
  
  
                              //                          Activity a = (Activity)photoToLoad.imageView.getContext();
  
                              activity.runOnUiThread(bd);
                          }
                      }
                      if(Thread.interrupted())
                          break;
                  }
              } catch (InterruptedException e) {
                  //allow thread to exit
              }
          }
      }
  
      PhotosLoader photoLoaderThread=new PhotosLoader();
  
      //Used to display bitmap in the UI thread
      class BitmapDisplayer implements Runnable
      {
          Bitmap bitmap;
          ImageView imageView;
          public BitmapDisplayer(Bitmap b, ImageView i){bitmap=b;imageView=i;}
          public void run()
          {
              if(bitmap!=null)
                  imageView.setImageBitmap(bitmap);
              else
                  imageView.setImageResource(stub_id);
          }
      }
  
      public void clearCache() {
          memoryCache.clear();
          fileCache.clear();
      }
  
  }
  </code></pre>
  
  <p>Is it possible to make images look better and not blur. I have also doen SCALE TYPE to FIT XY, but they get stretched and more blur.</p>