How do you center a UIImageView in UITableViewCell regardless of orientation?

I added two more autoresizing masks and got a good result using your code and PengOne's answer:

playImage.autoresizingMask = UIViewAutoresizingFlexibleLeftMargin | UIViewAutoresizingFlexibleRightMargin | UIViewAutoresizingFlexibleTopMargin | UIViewAutoresizingFlexibleBottomMargin;
[cell.contentView addSubview:playImage];
playImage.center = CGPointMake(cell.contentView.bounds.size.width/2,cell.contentView.bounds.size.height/2);

After you add backcover_imageView to the contentView of the cell, use this to center it:

imageView.center = CGPointMake(cell.contentView.bounds.size.width/2,cell.contentView.bounds.size.height/2);