Panoramas from .e57 Files

NavVis IVION can extract or reconstruct panoramas from .e57 Point clouds taken by a static laser scanner.

When you import a point cloud in .e57 format, NavVis IVION checks if there are panorama images embedded directly in the file.

If the file does not contain embedded images, NavVis IVION tries to reconstruct panoramas from the point cloud data based on intensity values or color (RGB) information.

Requirements for Panorama Extraction

NavVis IVION supports importing cube map images in the pinhole representation. If an .e57 file contains embedded panorama images, NavVis IVION extracts these images and converts them to equirectangular images.

Each successfully extracted panorama will correspond to a Location marker in NavVis IVION.

General Requirements for Panorama Reconstruction

If an .e57 file does not contain embedded panorama images, NavVis IVION tries to reconstruct panoramas for every scan location listed in the file.

A scan location is the point at which a static laser scanner was placed while scanning the area. Each scan location where a panorama was successfully reconstructed will correspond to a Location marker in NavVis IVION.

To reconstruct panoramas from an .e57 point cloud, the point cloud for each scan location must:

• Contain either color (RGB) information or intensity values. Otherwise panorama reconstruction is skipped for that scan location. Individual points without color information lead to black pixels in the resulting panorama.

• Be arranged in a grid with a height and width of at least 700x700 points. Otherwise panorama reconstruction is skipped for that scan location.

• Contain points across 360° horizontally. Otherwise the result will look distorted.

Note: .e57 projects containing RGB values must be exported separately from .e57 projects containing intensity values.

Structure Requirements for Panorama Reconstruction

To reconstruct panoramas from an .e57 point cloud, the point cloud must be structured. For NavVis IVION, structured means that:

• The points are assigned to the scan locations from which they were taken (scan-centric). A single .e57 file can contain points from multiple scan locations.

• The points for each scan location are arranged in a grid form with a height and width.

• The point cloud file contains metadata about the height and width of each grid.

You can export structured .e57 point clouds from standard point cloud processing applications for static laser scanners. Different applications have different names for this export option, but the results all work for import in NavVis IVION.

Organizational Requirements for Panorama Reconstruction

To reconstruct panoramas from an .e57 point cloud, the point cloud for each scan location should be organized to achieve the best quality. If the point cloud is unorganized, the points must be in either Cartesian or spherical coordinates. Otherwise panorama reconstruction is skipped for that scan location.

For NavVis IVION, organized means that:

• There is a point in the point cloud for every pixel of the grid.

• The number of points for the scan location is equal to the height and width of the grid.

If the point cloud is unorganized, NavVis IVION works around that and tries to fill in the missing pixels, but the result may contain some artifacts and black areas.

Note: .e57 point clouds can become unorganized if the processing software removes "invalid" points when exporting. Invalid points occur if the laser scanner does not find coordinates for the point. However, points without coordinates still contain color information which helps to reconstruct the panorama. Some processing applications remove these points when exporting, others do not. To export an organized .e57 point cloud, you may need to use a different processing software.

Note: Scanners with a tripod do not record points of a small circle on the floor at their own position while at that scan location. This circle cannot be filled in during panorama reconstruction, even if the point cloud is organized.

Importing .e57 Files

To import .e57 files, follow the instructions in Importing External Point Clouds. The panorama extraction and reconstruction starts automatically after processing the point clouds.