Backup_RPi_img.txt

Step 1: Read SD card using card reader

Step 2: Resize partition using "disk" utility

Step 3: Use below cmd to find last sector (512 Bytes) of last partition
sudo fdisk -l /dev/<sdc>
Ex:
Device     Boot  Start      End Sectors  Size Id Type
/dev/sdc1         8192   532480  524289  256M  c W95 FAT32 (LBA)
/dev/sdc2       540672 10307583 9766912  4,7G 83 Linux
==>> 10307583 is the last sector

Step 4: Backup all sector upto last sector
sudo dd bs=512 count=10307583 if=/dev/sdc of=~/SDCardBackup.img