Evropski sklad za regionalni razvoj
Indoor Mapping of a House with a Phone Camera

Indoor Mapping of a House with a Phone Camera

Location: Ljubljana, Slovenia
Date: June, 2018

In this project we will show you how to use our software in a bit different manner as in previous showcases. The object of use is a two-storey house, which is in the initial phase of the construction.

With our technology we decided to map the installations that are already in the house, in order to document the existing placement of different cables. This is how we will know, when the walls will be finished, where the installations are and in case of drilling holes in the wall we will be able to avoid any unpleasant situation. 

Dense point cloud house

To start with, these kinds of projects are also interesting because of the orientation itself – to measure ground control points (GCP), we don’t have to use expensive measuring instruments such as total station and GPS, which does not work inside the house. All we needed to do to measure GCP is to define the coordinates of the GCPs with the aid of a measuring tape. We chose two rectangular longer sides of the place, we measured them and then we made a *txt file from it for the orientation.

Local GCP points

 For the height we chose 100, so the coordinates at the end are not negative. 

Scan from Ground Floor to Upper Floor

On the ground floor, we made 77 photos in a way that we took a photo of every detail, on at least 3 photos.

Indoor Hand Shoots

We have to take care of how we are taking photos, as is shown on the image below:

Indoor mapping camera positions

When taking photos, you have to place yourself against the wall and then take the photos circularly. Do not place yourself in the middle of the room taking photos from the centre to the walls of the room. 

We did the same way on the upper floor – in our case we did 115 photos.

Room Scan from Photogrammetry

 Because the floors are connected only with the staircase it would have been very difficult to take photos of the entire house, so we did it in two separate projects. For the GCPs we used the same coordinates, we just added 3m of height, since the height of the ceiling is 2,70 m + the thickness of the panel 0,3. The orientation is working well in this way and it fits together. 

Measure anything you like

This resulted in 3D point cloud that enables the users to measure the distances between the different elements in the house – for example distance from different cables in the wall. It also enabled us to have a documented cross-section of the different layers in the house for future use and we will be able to see the specific of the desired layer in case we will need it. 

 

Tips: how to achieve better results?

  • Instead of the mobile camera use standard digital camera as those have a bigger size of the sensor (the number of the pixels in this case is not as relevant)
  • In the popup wizard for camera specification instead of clicking “estimate automatically”, insert the camera sensor width manually (Google the size of your sensor)

 

 

  • Location: Ljubljana, SLO
  • Date: June, 2018
  • Tool: Google Pixel I.
  • Camera: Integrated 12,3 MPIX
  • Orientation: Local coordinate system - 3 GCP points
  • Number of images: 182
  • Flaying height: / Hand shoots
  • Time of processing data on a high-performance computer: BA: 6 min, Orientation: 15 min, Dense reconstruction: 6h (on Extreme). Dof, volumes, profiles - on the GO.
  • DOF Resolution: no orthophoto, just point cloud
  • Area size: 90 m2
  • Results:
    • point cloud (ground floor + upper floor)
    • cross-sections on different heights