Question

I am facing this issue but unable to resolve. My problem goes like this:

• I have a list view. My list row contains an image view and one text view
• I have 20 images each of 12 MB size stored in my SD card
• I have to set these images in imageView of my list view

I am able to do it by following code. This I am doing in getView method of my custom adapter:

public View getView (int position, View convertView, ViewGroup parent) {
    //other stuffs like recycling, view holder etc...
    BitmapFactory.Options opt = new BitmapFactory.Options();
    opt.inSampleSize = 4; // tried with 8,12 too
    Bitmap bitmap = BitmapFactory.decodeFile(imageUri, opt);
    holder.imageView.setImageBitmap(bitmap);
    return convertView;
}

Now this code works fine with small images but plays havoc for image of large size. Application crashes with OutOfMemoryError. If I try to increase inSampleSize to 8 or 12, it works but image quality drastically comes down and image doesn’t look original image at all. I tried with imageView.setImageURI(imageUri) also but documentation suggests to use setImageBitmap only.

Now please someone help me to rectify this issue. How can I resolve this without compromising with image quality?

Answer 1

Try setting inSampleSize to 2 or 4, and scale width and height down using the Matrix class.
But as you said in another answer, this may hit performance.

float desiredWidth = 60; // the width you want your icon/image to be
float scale = desiredWidth/actualWidth // bitmap.getWidth() for actualWidth
// float scale = desiredHeight/actualHeight // If you want to go by a particular height

Matrix matrix = new Matrix();
matrix.setScale(scale, scale);

holder.imageView.setImageBitmap(Bitmap.createBitmap(bitmap, 0, 0, bitmap.getWidth(), bitmap.getHeight(), matrix, false));
bitmap.recycle(); // ish

Second option. Before instantiating the Adapter class, get a Cursor object to thumbnail images and pass the cursor into the constructor of the adapter, making it a class varaible. Use the same cursor on every view row in the ListView.

Uri tUri = MediaStore.Images.Thumbnails.EXTERNAL_CONTENT_URI; // Where thumbnails are stored
String[] columns = { MediaStore.Images.ImageColumns._ID,  MediaStore.Images.ImageColumns.DATE_TAKEN, MediaStore.Images.ImageColumns.DISPLAY_NAME};

Cursor thumbCursor = this.managedQuery(tUri, null, null, null, null); // May want to use more paramaters to filter results
cursor.moveToFirst();

.... instantiate adapter, pass in cursor ....

public View getView (int position, View convertView, ViewGroup parent) {

int columnIndex = cursor.getColumnIndex(MediaStore.Images.Thumbnails.DATA);
String filePath = cursor.getString(columnIndex);
Bitmap bitmap = BitmapFactory.decodeFile(filePath);
holder.imageView.setImageBitmap(bitmap);
cur.moveToNext();
// BitmapDrawable d = new BitmapDrawable(listActivity.getResources(), filePath);
// holder.imageView.setImageDrawable(d);
}

Something like that. I did it in a hurry. Good luck =)