Converting Pixel Coordinates to spatial coordinates: Python, Ros

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I tried using image_geometry, but i get a 'NoneType' object has no attribute '__getitem__' error when using it. Here's what i did

self.img_geo = PinholeCameraModel()
(r_x,r_y,r_z) = self.img_geo.projectPixelTo3dRay((359,28))

any idea whats going on?

I obviously imported the packages beforehand

You need to read in the camera calibration parameters

cam_info = rospy.wait_for_message("/camera1/camera_info", CameraInfo, timeout=None)
img_proc = PinholeCameraModel()
img_proc.fromCameraInfo(cam_info)
n = img_proc.projectPixelTo3dRay((30,30))

So I added that bit to my code, but it seems that the code stops at rospy.wait_for_message and doesnt compute the rest

So I figrued that that cam_info was basically just subscribing to a camera, so i replcaed the wait_for_message with directly subscribing to the camera. and the error that i get says that 'Subscriber' object has no attribute 'K'

Your first comment indicates, most likely, that you weren't publishing a CameraInfo message on the /camera1/camera_info topic. Your second comment indicates that you are passing the created subscriber into the fromCameraInfo method. That is not correct.

The wait_for_message function creates a subscriber, waits until the topic is published, and returns a copy of the message that was received. My code doesn't return a subscriber, it returns a CameraInfo message that has been filled out with information from camera calibration.

So given that I revert back to wait_for_message, how do i publish a CameraInfo message? You can't publish to the camera right, you can only subscribe to it