#1. Reading the block size and the volume size:
$ isoinfo -d -i /dev/cdrom | grep -i -E 'block size|volume size' 
Logical block size is: 2048
Volume size is: 327867
#2. Running dd with the parameters for block size and volume size:
$ dd if=/dev/cdrom of=test.iso bs=<block size from above> count=<volume size from above>

$ md5sum image.iso
$ md5sum /dev/sr0 #access to raw driver, not the mounted disk itself

$ bchunk <fichier.bin> <fichier.cue> <fichier.iso>