Extracting The Information Of Water System Based On Texture And Analysis Of The Water System Features

Water system information is one of the core of geographical scientific information, the development of water system, combination types are influenced by lithology, rock structure, regional structure environment, etc, which performs as a certain regularization the planar graph. Therefore, the water system must reflect the lithology, geological structure characteristics, via the analysis of the water system map, estimate the relevant circumstances of lithology and geological structure. Texture information of remote sensing reflects the spatial distribution of image gray-scale patterns, including the surface information of the image and its relationship with the surrounding environment, water system has obvious spatial distribution. We could extract water system through texture analysis of remote sensing image.Because of inequality of the sun's radiation, Gullies on both sides have different strength, reflected in the remote sensing images with different brightness values. For the northern hemisphere, the remote sensing data from the south-east of the sun exposure generally, so the north-west side of the image brightness is significantly higher than the southeast. By comparing with the location of sunny slope and shade slope, we can determine the location of the water. Water is in the border of image brightness mutation, and the brightness variety distribution is directional changes, which makes up of the texture characteristics of water system.In this paper, gray-scale co-occurrence matrix and wavelet transform method are used to extract water system. Gray-level co-occurrence matrix is built on the probability density function of second-order combination condition in the image, by calculating the probability from one gray-value to another between a certain direction and a certain distance, which reflects the synthesis information of texture changes in the image. The variance character value of Gray Level Co-occurrence matrix can reflect the local transform information of gray value. Gray-scale co-occurrence matrix statistical and numeration can receive variance character image, the area with bigger gray-scale transform mostly includes gully and ridge, which show high-lighted values in variance character image. Set the threshold characteristics and get water and ridge form variance character image, then differentiate the water and ridge according the sunny slope and shade slope, finally extract the water system.Wavelet transform is a local transformation about time and frequency, which can extract information effectively from the signal. Make Wavelet transform of images, the gray-scale point mutation is zero value, and from light to dark the wavelet transform results are from the positive to negative ,and vice versa for the wavelet transform values from negative to positive, according to The characteristics extract water information. Horizontal and vertical wavelet transform are included, after transform we can get the corresponding the data matrix, the brightness values of water in the image on the left side and upside were relatively higher than the other direction respectively, in the results matrix reflected from positive to negative values of the points .Finally extracted water system according to the numerical analysis of Matrix of the results.The development of water is closely related with landforms, lithology, geological structure, that is, a certain water system must reflect a certain lithology and geological structure. Through the analysis of water density, symmetry, direction, pattern, etc, we can confer the general situation of the background lithology and geological structure. This article using ETM data to extract water system of Dandong region, and analyse the water system map, according to the characteristics of water system carve up background rock.In this paper, via water system information extraction based on texture features and lithology carve up using water system characteristics ,we get some conclusions as follows:(1)The texture information reflects the special characteristics of the identity, which contains abundant information, through the analysis of texture features ,we can identify some information that can not be extracted through spectrum characteristic ,such as gully and valley, and which can realize the automatic extraction about water system information.(2)Gray-level co-occurrence matrix can describe gray-scale spatial distribution and structural characteristics of every pixel gray-scale effectively, and the variance statistic in which reflects the changes in images of local information, which can embody the water system texture well.(3) The wavelet transform is a local transformation between time and frequency ,which can extract information effectively from the signal. Water system extraction based on wavelet transform has high precision, contains much information, and have good potential for water extraction in remote sensing images .(4) Carving up geological background based on water system characteristics has high credibility, which provides a good approach for geological research of coverage and half coverage area.