Mark Salling: Bails Out After Child Porn Arrest

Mark Salling has bailed out of jail with the help of his family ... this after his arrest for allegedly possessing more than a thousand child porn images.

We got a shot of Mark leaving the jail -- leaning back out of view in the passenger's seat -- after being booked on possession of child porn ... specifically porn involving minors "engaging in or simulating sexual conduct."

We've learned the bail was set at $20,000 and his family posted it ... they put down $2k, or 10%.