dd if=/dev/sr1 of=IDT.img conv=sync,noerror status=progress
Though, there is a recommendation to use ddrescue (not part of ubuntu)
Use ddrescue. It can read damaged media "preserving" damaged parts while dd cannot.
Imagine your original data:
+-+-+-+-+-+-+-+-+-+-+-+-+
|a b c d e f g h i j k l|
+-+-+-+-+-+-+-+-+-+-+-+-+
After damage (X) they look like that:
+-+-+-+-+-+-+-+-+-+-+-+-+
|a b c X X X X h i j k l|
+-+-+-+-+-+-+-+-+-+-+-+-+
What dd conv=sync,noerror will read:
+-+-+-+-+-+-+-+-+
|a b c h i j k l|
+-+-+-+-+-+-+-+-+
What ddrescue will read.
+-+-+-+-+-+-+-+-+-+-+-+-+
|a b c 0 0 0 0 h i j k l|
+-+-+-+-+-+-+-+-+-+-+-+-+
As you can see original message read by dd is skewed and if you produce this way filesystem image it will be rendered unusable. Ddrescue image you are able to mount witout problem which will help you to access undamaged data as usual and damaged to be easily put aside and dealt next.