What version of AE do you have?
You must furst roto the gargabe can so that you can create a mask layer reveal just the object. If anything passes between the camera and the garbage can you also need to roto that object to that it will leave a hole in the mask.
You can then use the clone stamp, or sample other areas of the video, or create a photoshop image that fills in the hole using a copy of the frame as the source.
There's a good tutorial on using Mocha to replace a background. It should get you started.
Hello, I have this video of a car driving in the street. and it's passing by this garbage can that i need to completely remove from the video. how do I do this? this was given to us as an assigment after a rotoscoping class. but i have no idea where to begin...
Homework assignments for After Effects are not handed out without adquate preparation, that would be indefensibly lazy behavior for the instructor. Like physics or chemistry homeworkl, such assignments go out the door only after careful instruction, demonstration of complex concepts, samples, discussion, question and answer sessions and providing adequate resources. An After Effects class implies there is a comprehenisve text with a complete section on rotoscoping, a training DVD that came with the text and a handout that included endless online resources, not to mention the other students in the class who are facing the same problems.
You will find AE is no less complicated than physics or chemistry, it's just not as dogmatic.
Open the book.
Attend the study group or start one.