MAPPPING DIGITAL IMAGE TEXTURE ONTO 3D MODEL FROM LIDAR DATA 
Chunmei Hu a ’,Yanmin Wang a ,Wentao Yu b 
a School of Geomatics and Urban Information, Beijing University of Civil Engineering and Architecture, 1# 
Zhanlanguan Road, Beijing, 100044, China,-(huchunmei81)@ 163.com 
b The Second Engineering Department, Heilongjiang Bureau of Surveying and Mapping, Cehui Road, Harbin, 150086, 
China, - yuwentao81@163.com 
Wgs-PS WGV/3 
KEY WORDS: LIDAR Data, Point Cloud, 3D TIN Model, Digital Image, Texture Mapping, Error Correction 
ABSTRACT: 
In this paper, an experiment system is developed to settle the problem about how to mapping a digital image onto 3D model from 
LIDAR data. Firstly, it chooses the corresponding points between point cloud and digital image, then, uses these corresponding 
points to calculate the exterior and interior orientation elements and systematic error corrections of image. For the purpose of 
improving the precision of these parameters, paper uses the iterative least squares computational method. The digital image comes 
from non-metric camera, and the initial values of orientation elements can not been obtained, so, paper replaces the collinearity 
equation of photogrammetry to calculate these parameters with the DLT. Finally, by using the texture mapping technology, paper 
maps the corresponding image onto point cloud model and TIN model, makes out textured point cloud model and textured TIN 
model. At the same time, it projects this image to the basic level of range image to make out orthophoto map. 
1. INTRODUCTION 
In recent years, the Laser Scanning technology has made a great 
progress in many application fields, such as historic buildings 
protection, 3D reconstruction and other aspects, and the texture 
mapping of 3D model is an important content in these fields. At 
present, some software such as Texcapture, RapidForm have 
actualized texture mapping function. However, it has been 
proved that these software’s functions are limited for the 3D 
model from LIDAR. On one hand, RapidForm’s precision can 
not achieve request. On the other hand, although Texcapture’s 
precision has achieved request, the result of texture mapping is 
not satisfying. Sometimes the edge of texture mapping would 
be declining, and for the large model data, the result of texture 
mapping can not be displayed by the software. So, it is 
significant to develop software of texture mapping based on the 
Laser scanning data and digital image to realize the data fusion. 
Paper develops an experiment system to realize the data fusion, 
and the principle and method about this experiment system are 
introduced in follow sections. 
2. SELECTING CORRESPONDING POINT 
The system need picking up corresponding points in the screen 
from digital image and point cloud model to calculate the 
orientation parameters between image and point cloud. For 
calculating these parameters, at least 6 pairs of corresponding 
points should be selected. There is a valuable noted point that 
corresponding points should be distributed around the image 
and point cloud with image bound as the first. These can be 
considered by the principle of photogrammetry. 
2.1 Selecting Character Points in Digital Image 
There has used the function of screen coordinates selection. 
When the mouse points the character point, system get the 
screen coordinates. Then, we should convert the coordinates 
from screen to image. For improving the selected point 
precision, the image had better to be magnified to the pixel 
level. 
2.2 Selecting Corresponding Character Point in Point Cloud 
Because the point cloud model is 3D, the paper utilizes the 
projection radial method to pick the 3D coordinate from screen 
point. First, by using the two points of intersection which come 
from the intersection of screen point projection radial and near 
and far cross sections, we can get this line equation. Then, 
according to calculating the distance between the line and the 
model points, the points within a threshold can be selected. At 
last, we chose a nearest distance point as the 3D coordinate of 
screen point after calculating the distance between the selected 
points and the viewpoint. Figure 1 is a pair of corresponding 
point. 
Figure 1 Corresponding Point 
3. CALCULATING THE PARAMETERS OF 
ORIENTATION AND LENS DISTORTION 
For actualizing the registration between digital image and point 
cloud, we should firstly calculate the parameters of orientation 
and lens distortion. The digital image comes from the non 
metric camera, which can not supply the initial value of