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PEER REVIEW
PEER REVIEW
The Malaysian Surveyor
marked points projected in a straight
line from the camera station, through
the film. When the marked point
is constructed on the images, it is
possible to generate 3D model. One
of the objectives of this research is
to generate a 3D indoor modelling
by using sequential images.
Figure 8 shows the 3D indoor
model of the research area. The
3D model is based on close range
photogrammetry and it shows all the
features inside the building.
The 3D model of the building is
Figure 7: Referencing process
based on 15 images; the length
was compared with the actual
measurement in the real world using
better to use original images for all constructed by choosing points, a measuring tape. The distance
photogrammetric processing, or lines, edges, and curves of the 3D between the camera station and
project them on cylinder instead of objects. It gives the ability to create object during the capturing is about
planes. 3D model by marking in one image. 3-4 meters. Images were taken
It is useful to draw a detailed feature with DSLR Sony SLT-A35. There are
Once the images are oriented, in one plane such as façade of the several factors that the 3D model
the scale and rotation need to building. Drawing a surface does deformed such as the incorrect way
be inserted for the purpose of not require any referencing process of marking points during referencing
comparison between real world so that the detailed in features are process, the lack of overlapping
measurement and 3D measurement. much easier to mark. image will cause deformed the
The absolute value is assigned to the model since it needs to have enough
length of the feature but it is not an point coverage and poor angle of
actual value. Correction needs to be 3. Results and camera defect the model because
made by entering a known distance Analysis points will repeatedly mark the same
between two points in the model. location on the images. Good angle,
The unit must be in meters and The interior orientation process well-distributed points marked, and
to define the distance, two points recreates the geometry inside quality of images give a good result
or lines must be picked. A surface the camera. It requires camera of generating a 3D indoor model.
calibration information to begin the
measurement of image points. The
principal point and lens distortion
Good angle, well- are used to refine the coordinate
correctly. Referencing process is
distributed points carried out in order to complete
relative orientation. At least, 10 to
marked, and 15 points are marked in one stereo
quality of images pair. A successful referencing
process is based on the residual of
give good results the images. The total residual of all
images cannot exceed 5 pixels; this
in generating a 3D is due to maintaining the quality
indoor model. of the images. The residual can
be corrected by re-do the camera
calibration and use the best camera
calibration information as possible.
3D positions were generated when Figure 8: 3D indoor model
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