The Method Research On Remote Sensing Phantom Pretreatment And Terrain Feature Extraction

The second national land investigation aimed at the countryside land, based on the orthogonal projection elephant, investigates each land's using conditions outside cities, such as kind, position, scope, area, distribution and so on, establishes fast renewal mechanism of the land resource information, provides the reliable basic data and the comprehensive service for each item of land resource management service. But based on the principle land investigation taxonomic approach of open country investigate, the difficult work does not the most major problem, as the time span is very big, the data effectiveness with difficulty guaranteed, therefore, the conventional routes of remote sensing image interpretation has faced with huge challenge. Along with the development of computer imagery processing technology and remote sensing technique, the research and the application of the terrain feature of automatic extraction of remote sensing image obtains people's favor more and more. Take the remote sensing image pretreatment as the foundation, realizes automatic extraction of the remote sensing image terrain feature, gains the different topic information of the surface fastly, and uses these special information renewal geography database fastly, it is not only one of the basic researches of remote sensing image automatic understanding, but also is the benefit efficient path which can increase the precision and the work efficiency.On the basis of summarizing and analyzing the method of imagery processing technology and phantom terrain feature automatic extraction, this article takes the land utilization present situation of Jianzha County, Qinghai Province as the example, conducts the research with the Quick Bird remote sensing phantom as the data pool, does the work as follows:(1)Carries on the analysis to the feasibility of terrain feature automatic extraction, summaries four big difficult problems which can meet to the unification automatic extraction of phantom terrain feature: shadow and terrain influence, region difference influence,"same thing but different spectrum"and"same spectrum but foreign matter"phenomenon influence, land utilization type multiplicity. Through analyzes present interpretation technology, discoveries theoretically that can solve the shadow and terrain influence,"the same spectrum but foreign matter and the same thing but different spectrum"phenomenon, raises the phantom interpretation speed and precision to a certain extent.(2)Eliminates the terrain and the shadow influence. Because the cloudy and sunny slope, the different terrain feature height influence as well as the sunlight illumination, presents the terrain feature camouflage and the shadow phenomenon. This causes information in the phantom to be disturbed or losed which in the defiladed area and the shadow region, and brings the difficulty to ground-objects identification. This article adopts the image operation and the piecewise linearity transformation method to process phantom which has bit drop-out, to a certain extent enhances the terrain feature recognition in the phantom.(3)Base on the image intensification method, this paper selects the homomorphism filter method of frequency domain strengthens, the histogram to be balanced method of spatial domain strengthens, the elimination haze method of radiation strengthens pretreat remote sensing phantom, makes kind of terrain feature characteristic to be brighter in the phantom.(4)Through analyzes the quite popular terrain feature information automatic extraction method, the paper chooses object-oriented method to classify the phantom. Based on the comprehensive characteristic analysis, which contains research area phantom's spectrum value, spatial distribution, texture structure and so on, constructs the terrain feature regular tree of research area, obtains the object-oriented method classification result, through carries on the contrastive analysis with the maximum likelihood method classification result, discovers that object-oriented method's accuracy is higher than the tradition based on the element taxonomic approach, especially has the overwhelming superiority when to automatic extraction terrain feature information of phantom, which has"the same thing but different spectrum","the same spectrum but foreign matter"phenomenon.