Research And Analysis On The Process Of Digital Images In Distance Interactive Teaching

Modern distance education is a new method of education, relying on computer and networks technology and multi-media technology. The learner-centered education method is performed in the form of postal tuition, face-to-face tuition or self-learning. Multi-media technology is used to establish the relationships between teachers, students and educational institutions. Nowadays Modern distance education has become an important method of education.But in reality, modern distance education hasn't achieved ideal goals due to various reasons, of which are inadequate interactivities. Information interaction is the key factor in distance education, reflecting the actual teaching designs and applications.This thesis, based on the Conversation Pattern of Learning Process by Laurillard in 2000, proposes significant additions to the interactivity of students and media interface, the expansion of conversational interactive objects, the classification of adaptable interaction and the changes of concepts, forming interaction pattern of distance education and figuring out the technological factor which influences the interactive effect, i.e. distorted images.The modification of distorted images is a matter of the process of digital pictures. Generally, distorted images are produced mainly because of using lower-quality facilities, such as low-pixel cameras equipped with optical distorted leans, and scanners. Such facilities are not even fit in static image acquisition, let alone in dynamic image acquisition.To improve the accuracy of quantitative analysis of pattern matching and image detection, and minimize the effect of distorted images, it is necessary to modify the distortion. Since the end of last century, experts in home and abroad have put forward scores of methods about camera non-linear rectification. All these methods belong to two categories according to their principles. One is object-based and the other pattern-based. With its own characteristics, the accuracy of rectification of each method is affected by adjustment precision, calculation, and real-time performance. None of methods can provide an ideal solution to recover complicated non-linear distorted images.By analyzing the teaching environment of modern distance education, the thesis draws the conclusion that most of the digital images produced in such activities have small (or medium) objects in a big background. Just qualitative identification is enough in the modification of such images. However, high correction speed in such environment is needed. This thesis puts forward a direct look-up table method based on coordinate interpolation, that is, forming a reference pattern through plenty of experimental data by establishing the approximate correspondence before and after distortion of the image. In the process, the key factors affecting rectification should be taken into consideration and it is also necessary to shrink the goal area and simplify the difference before and after the distortion of the image. X and Y coordinate values of each point before distortion can be achieved by looking up the X and Y coordinate values of each point after distortion in the table. This method has good effect because of the smaller goal area, fewer pixels and higher speed in real-time calculation.