Is it possible to calculate world coordinates of a pixel given its pixel coordinates in a photo and camera calibration values?

Hi,

I am trying to calculate world coordinates of some points in the set of aerial (drone) photos. The set of photos was processed and aligned within the aerotriangulation process in the Pix4D software. For exemplary point, I have its pixel coodinates, camera calibration values (e.g. focal length, cx, cy, calculated distortions, photo size etc.) along with camera position in world (external) coordinate system.

I am trying to reverse engineer the steps for calculating pixel coordinates based on world coordinates in this article, but trying to go from 2D to 3D coordinates in the camera coordinate system, I lack the information about Z value and it's probably not possible to obtain it based on the data I have.

Could anyone, please, confirm that my logic is valid and I cannot calculate world coordinates, given the data I have? If so, what information is needed to calculate these world coordinates? Or is it possible only with at least 2 photos? (stereography)