In order to work, photogrammetry requires multiple images of a scene that have been captured from distinct angles. For simplicity, TeleSculptor refers to these distinct images as frames, whether or not they are derived from a single, continuous video. Although a frame corresponds to a camera pose, the term “frame” is used to indicate instances where the pose may not yet be known.
Camera Model:

In TeleSculptor, a camera model (often shortened to “camera”) describes the intrinsic and extrinsic parameters of a camera at a given frame. Intrinsic parameters include focal length and lens distortion. Extrinsic parameters are the camera pose — orientation and position. A frame may have at most one camera pose, which is unique to that frame. While extrinsic parameters are never shared across frames, intrinsic parameters may or may not be shared depending on the algorithm that produced them.

In the GUI, cameras are represented as rectangular pyramids. The peak of the pyramid is the camera center of projection. The rectangle base is proportional to the image aspect ratio, and a triangle attached to the base indicates which direction is “up” in the image. The pyramid visualizes the field of view of the camera.

A feature describes a salient point in an image. Features have enough visual texture that they can be reliably localized in images across time. Features are also known as interest points or corner points.
A (feature) track is a collection of correlated features; that is, detected feature points estimated to correspond to the same landmark.
A landmark is an estimated 3D world point that, when projected into the images, gave rise to an observed feature track.
A residual, in general, is the difference between an observed value and an estimated value[1]. In TeleSculptor, the observed value is typically a detected feature point, and the estimated value is the projection of its corresponding landmark into the image.
Ground Control Point (GCP):
A ground control point is a 3D point that is manually placed in the scene by a user. Ground control points are often attached to an identifiable location from a reference image or map. The user can assign the true geodetic location (latitude, longitude, elevation) to a ground control point, and that ground control point can then serve as a constraint when geo-registering the model.
Camera Registration Point (CRP):
A camera registration point is a 2D point that is manually placed by the user in one or more frame images. Camera registration points are associated with a ground control point and can tie that ground control point to multiple images, even when no camera model has been estimated. Whereas a ground control point is the manually placed version of a landmark, a camera registration point is the manually placed version of a feature track. A collection of camera registration points can be used to manually estimate a camera model when automated feature matching is not possible.