THE RESEARCH AND IMPLEMENTATION 
OF DYNAMIC EPIPOLAR REARRANGEMENT 
BingXuan GUO a , YuanZheng SHAO\ ZhiChao ZHANG 8 , LingYan Dong 3 
a State Key Lab of Information Engineering in Surveying Mapping and Remote Sensing, 
Wuhan University, China - mobilemap@gmail.com 
Commission WGS-PS, WG IV/9 
KEY WORDS: Epipolar Image, Dynamic Epipolar Rearrangement, Image Pyramid, Stereoscopic Observation, Memory Pool 
ABSTRACT: 
Image re-sampling according to epipolar geometry is a prerequisite for a variety of photogrammetric tasks such as stereoscopic 
observation. Executing stereoscopic observation by virtue of a pair of epipolar images is a common approach. This paper proposes a 
new approach to generate epipolar images and measure in stereoscopic environment. In order to improve the accuracy of 
stereoscopic observation, a dynamic epipolar rearrangement (DER) method is presented. In this method, there is no need to construct 
the epipolar image pyramid, because the needed epipolar images for measurement is dynamically generated from the original stereo 
pair pyramid. Then scale the epipolar images and transfer it to the screen buffer directly for stereoscopic observation. The key 
technology and method for stereoscopic observation, such as constructing pyramid image data structure with high fidelity, 
dispatching image data by using multi-threaded and memory pool strategy to accelerate the speed of image display, especially the 
integration operation of integrating the generation of epipolar images with the transfer of the epipolar images to the screen buffer, are 
deeply investigated. 
1. INTRODUCTION 
At present, digital image acquisition of high resolution, 
accuracy and multi-spectrum and real-time imagery is coming 
true, how quickly and efficiently to survey the interested targets 
and obtain the information from these images has become an 
active research topic in digital photogrammetry. 
The traditional stereoscopic observation strategy is to generate 
epipolar images after obtaining the stereo pair [1], then the 
stereopair is tiled and the epipolar images pyramid data 
structure are constructed from the original stereopair, which 
create different layers with different resolution [6], [9]. In the 
course of stereoscopic observation, the images in the epipolar 
pyramid, which belong to different tiles and layers, are 
scheduled with the change of the viewpoint. 
There are three main truncation errors about the traditional 
strategy. The first exists in the course of generating epipolar 
images from the stereopair. The second error is introduced 
when constructing epipolar images pyramid, which is because 
the common pyramid algorithm have the loss of accuracy. The 
third is due to pixel truncation when transfer the epipolar image 
to screen buffer. The cumulative error caused by the above 
three errors affect the accuracy that match the cursor with the 
interested objects in stereoscopic observation, leading to the 
decrease of measurement accuracy consequently. 
To deal with these errors and restrictions, a cylindrical 
rectification technique was proposed in [2] which used a 
separate transformation for each epipolar line. However, the 
technique was complex, omitted many implementation details 
and worked largely in 3D. A later work, [3] overcame most of 
these problems, by using the tools of oriented projective 
geometry to perform a similar nonlinear rectification without 
using 3D. 
In this article, the key technology and method for stereoscopic 
observation, such as pyramid image, multi-threaded and 
memory pool strategy, will be researched. In order to improve 
the accuracy of stereoscopic observation, a dynamic epipolar 
rearrangement!DER) method is presented. In this method, there 
is not necessary to construct the epipolar image pyramid, 
because the needed epipolar images for measurement is 
dynamically generated from the original stereopair pyramid. 
Then scale the epipolar images and transfer it to the screen 
buffer directly for stereoscopic observation. 
In Sections 2 the related technologies, such as constructing 
pyramid image data structure with high fidelity, dispatching 
image data by using multi-threaded and memory pool, are 
considered. Section 3 describes the strategy of dynamic 
epipolar rearrangement. Section 4 presents the systematic 
integration which illustrates the full process. A proving 
experiment is also performed in section 5 and the conclusion is 
drawn in section 6. 
2. BACKGROUND 
2.1 Epipolar geometry 
The epipolar geometry is the intrinsic projective geometry 
between two views. It is independent of scene structure, and 
only depends on the cameras' internal parameters and relative 
pose [7]. 
An epipolar line is the intersection of an epipolar plane with the 
image plane. All epipolar lines intersect at the epipole. An 
epipolar plane intersects the left and right image planes in 
epipolar lines, and defines the correspondence between the lines. 
The epipolar geometry between two views is essentially the 
geometry of the intersection of the image planes with the pencil