Questions[resize](ubuntu)

Context

I have a 16 GB SD card with a Linux based OS for a Raspberry Pi. Most of the space is empty.

I want to share the SD .img with other people but if I use the command

dd if=/dev/sdXX of=/home/user123/SD.img

it will create a 16 GB image. Too big.

Question

How can I re-size a 16GB SD card image into a smaller 4GB?

I have tried with GParted: it creates a partition with 4GB with no problem, however the whole .img of the SD card continues to be 16 GB with 12 GB of unallocated space.

I have read the question and answer Cloning multiple partitions in Ubuntu, but I still cannot re-size the 16GB SD card into a 4GB one.

More info

~$ lsblk 
...

sdc      8:32   1  14,9G  0 disk 
├─sdc1   8:33   1   100M  0 part 
└─sdc2   8:34   1     4G  0 part 

~$ sudo fdisk -l /dev/sdc
Disk /dev/sdc: 14,9 GiB, 15931539456 bytes, 31116288 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0xf8a631ce

Device     Boot  Start     End Sectors  Size Id Type
/dev/sdc1  *      2048  206847  204800  100M  c W95 FAT32 (LBA)
/dev/sdc2       206848 8595455 8388608    4G 83 Linux

Any advice is appreciated!

Please note: as observed by Melebius in a comment, the right word to use is shrink:

You cannot resize an SD card as it is hardware with a given capacity that cannot be changed. You clearly want to shrink an SD card image.

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apt search ubuntu.*tweak

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