As part of a script, I am trying to find the image ID's of already made images. When I run this command for instance:

```
ec2-describe-images --filter "description=$instance_ID" -O $O -W $W

```

It returns all information on the resulting images. 

```
IMAGE ami-##dc64da ######/i-e45d81c4/141014 ##### available private x86_64 machine
aki-##### ebs paravirtual xen BLOCKDEVICEMAPPING EBS /dev/sda1 snap-##### 8 true standard
BLOCKDEVICEMAPPING EBS /dev/sdb snap-##### 100 false standard BLOCKDEVICEMAPPING EBS /dev/sdf
snap-##### 100 false standard

```

Is there anyway I can return only the image id `ami-##dc64da`?