read from my text for my starting project

Im a newbie still little things I can do, just watching some tutorial , I believe starting this project I will learn more.

here what Im trying to do.

I want to read the data from a text file, I have room number and a image file info, when I run this, the info for the room will made a folder and the image info will be copy inside the folder. 

this might be the text containing

room: 1234

image name: honson.jpg

room: 2333

image name: walter.jpg

room: 5467

image name: bamboo.jpg

$imgdir = C:\images
$content =Get-Content C:\Users\You\Documents\book.txt
foreach ($line in $content)

i dont know how to remove the "room:" and to get only 1234 and copy honson.jpg and remove "image name:"

thank you in Advance ..