For Blender users, there is an official fSpy importer add-on that sets the parameters of the Blender camera and optionally sets the camera background image.

Follow these instructions to get started.

Getting your camera parameters into an applications without a dedicated importer is likely possible and involves copying the fSpy parameter values one by one and pasting them into the target application. Here's an outline of the process:

• Set the camera viewport to match the dimensions of the input image
• Use the input image as the camera background
• Set the camera field of view
• Set the camera position
• Set the camera orientation
• Set the principal point, unless it coincides with the image midpoint