如何优化我在GridView中使用的图像？

Question

我在Android中有一个基本的GridView以及它的自定义布局。我想知道，如何让我的应用程序在显示图像时更加优化？它与它们的大小有关（我想我会坚持使用450x450px）还是我实施像Picasso这样的东西来管理图像？

GridView适配器

    public final class GridViewAdapter extends BaseAdapter {
    private final List<Item> mItems = new ArrayList<Item>();
    private final LayoutInflater mInflater;
    private int i;
    private String imageText;
    private boolean hasDescription;

    public GridViewAdapter(Context context, ArrayList<String> arrayListName, ArrayList<String> arrayListDescription) {
        mInflater = LayoutInflater.from(context);

        if (arrayListDescription != null){
            i = 0;
            while(arrayListName.size()>i) {

                imageText = arrayListName.get(i).toLowerCase().replace(" ","");

                mItems.add(new Item(arrayListName.get(i), arrayListDescription.get(i), context.getResources().getIdentifier(imageText, "drawable", context.getPackageName())));
                i++;

                hasDescription = true;

            }
        }
        else{
            i = 0;
            while(arrayListName.size()>i) {

                imageText = arrayListName.get(i).toLowerCase().replace(" ","");

                mItems.add(new Item(arrayListName.get(i), "",context.getResources().getIdentifier(imageText, "drawable", context.getPackageName())));

                i++;

                hasDescription = false;
            }
        }

    }

    @Override
    public int getCount() {
        return mItems.size();
    }

    @Override
    public Item getItem(int i) {
        return mItems.get(i);
    }

    @Override
    public long getItemId(int i) {
        return mItems.get(i).drawableId;
    }

    @Override
    public View getView(int i, View view, ViewGroup viewGroup) {
        View v = view;
        ImageView picture;
        TextView name;
        TextView description;

        if (v == null) {
            v = mInflater.inflate(R.layout.grid_item, viewGroup, false);
            v.setTag(R.id.picture, v.findViewById(R.id.picture));
            v.setTag(R.id.text, v.findViewById(R.id.text));
            v.setTag(R.id.description, v.findViewById(R.id.description));
        }

        picture = (ImageView) v.getTag(R.id.picture);
        name = (TextView) v.getTag(R.id.text);
        description = (TextView) v.getTag(R.id.description);


        Item item = getItem(i);

        picture.setImageResource(item.drawableId);
        name.setText(item.name);

        if (!hasDescription){
            description.setPadding(0,0,0,0);
        }
        else{
            description.setText(item.description);
        }

        return v;
    }

    private static class Item {
        public final String name;
        public final String description;
        public final int drawableId;

        Item(String name, String description, int drawableId) {
            this.name = name;
            this.description = description;
            this.drawableId = drawableId;
        }
    }
}

方形图像视图

    public class SquareImageView extends ImageView {
    public SquareImageView(Context context) {
        super(context);
    }

    public SquareImageView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public SquareImageView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        setMeasuredDimension(getMeasuredWidth(), getMeasuredWidth());     
     }
}

布局

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent" android:layout_height="match_parent">

    <com.example.package.SquareImageView
        android:id="@+id/picture"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:scaleType="centerCrop" />

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="bottom"
        android:orientation="vertical">
        <TextView
            android:id="@+id/text"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:paddingLeft="10dp"
            android:paddingRight="10dp"
            android:paddingTop="5dp"
            android:paddingBottom="5dp"
            android:textColor="@android:color/white"
            android:textSize="15sp"
            android:background="#55000000"/>

        <TextView
            android:id="@+id/description"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:paddingLeft="10dp"
            android:paddingRight="10dp"
            android:paddingBottom="5dp"
            android:textColor="@android:color/white"
            android:textStyle="italic"
            android:textSize="12.5sp"
            android:background="#55000000"/>
    </LinearLayout>
</FrameLayout>

目前有一些图像，我的内存使用量约为50-100mb。也许有办法将它们缓存到SD卡？你们建议使用另一个线程来加载图像吗？

谢谢！