Image Set

An Image Set node represents multiple images of the same scene along with extra data like per-image camera poses, 3D sparse points, image masks or detected AprilTags.

General

Images Import/Select/Track

This field shows the numbers of images in three stages of processing:

Import is the number of image files or video frames that were imported.
Select is the number of images that were selected based on the Max Image Count parameter.
Track is the number of images that have camera poses available, either from a pose import or from Postshot's camera tracking process.

Camera tracking by

This field displays the version of Postshot that did the camera tracking for this image set.

Sparse Points

This field displays the number of sparse 3D points there were extracted from the images or imported. These points will be used to initialize the radiance field training.

Mask Mode

If the Image Set has associated image mask files, the Mask Mode selects whether the masks remove occluders (foreground) or the background.

Note that in either case the white/active part of the mask images marks the regions that will be used in the model.

Timeline Selects Image

If this option is checked, the timeline can be used to select an image from the Image Set. See also Selected Image.

Selected Image

Selects an image from the Image Set to display its details in the Image Properties section below and to use its camera pose in the viewport, if the Image Set node is selected as the Viewport Camera.

Image Properties

Filename

Displays the external file path of the image or video file and frame number.

Postshot does not store images or videos in a .PSHT project file but only paths to external files. If the external paths change, the Relocate Files action can be used to update the project file.

Mask Filename

If the selected image has an associated image mask, its path is displayed in this field.

Resolution

The resolution of the original image in pixels.

If the Downsample Images option is active, the a lower resolution will be used for training.

Lens Shift

Lens Shift is also known as the Principal Point. It is the negative of Sensor Shift.

This value is part of the intrinsic camera parameters. Unless the Single Lens & Focal Length option was checked during training, each image may have different values.

Focal Length

The Focal Length value displayed here was computed from the image during the camera alignment process. It can deviate from the Focal Length value specified by the lens manufacturer. However, if the discrepancy too high, this can indicate a failure in aligning the image.

This value is part of the intrinsic camera parameters. Unless the Single Lens & Focal Length option was checked during training, each image may have different values.

Radial/Tangential Distortion

The distortion coefficients model the lens distortion based on the Brown-Conrady model.

These values are part of the intrinsic camera parameters. Unless the Single Lens & Focal Length option was checked during training, each image may have different values.

Position

This field displays the position of the camera center in world coordinates as determined by the camera alignment process.

Rotation

This field displays the tilt/pan/roll rotation of the camera as determined by the camera alignment process.

Actions

Create Camera

Creates a new, animated Camera object in the Scene Tree that moves through the camera poses of the Image Set.

This Camera object can be used to

export the camera poses from the Image Set via the File / Export Cameras... menu,
render the reconstructed scene from the original camera poses,
as a starting point for manual camera animation.

Export Images

Re-export the image files that are be used to train the radiance field. This works both for extracting the selected images from a video file or to convert the original images to a different image file format.

Relocate Files

Relocate the external image or video files to new file paths.

Postshot does not store images or videos in a .PSHT project file but only paths to external files. This action can be used to point the Image Set to new external file paths.

This may be necessary if the have been moved. It can also be used to replace the images with versions that have been processed or converted to different file formats.

Export COLMAP database

The camera poses and points extracted form the images during camera tracking or imported from external files can be exported in COLMAP database format.