頻數多邊圖 的英文怎麼說
中文拼音 [bīnshǔduōbiāntú]
頻數多邊圖
英文
frequency polygon-
In the terms of interpolation, the image reconstructed from nearest interpolation or linear interpolation has good edge but serious noise ; reconstruction from 4 * 4cubic interpolation or three b - spline or three - order lagrange interpolations has better local character. 2 x 2cubic interpolations which has both better edge and local character is the ideal interpolation, the following is the basic principle during reconstruction : ( 1 ) the more width of interpolation, the more number of summation and the more order of interpolation polynomial, the higher of density resolution ; ( 2 ) the more of interpolation polynomial and width of interpolation, the more of reconstruction time simultaneously, aimed at eliminating the effects of noise contained in projection data, in this paper, author analysis cause and effects of common artifacts. importantly, discusses convolution back - projection reconstruction algorithm with a shift axis of rotation has been derived for correcting images that acquired with a divergence axis of rotation using the fan beam geometry with an angle - equaled detector
在ct圖像重建時，選擇有限帶寬窗有較好的空間解析度，三角形窗有較好的密度解析度，選擇餘弦窗則使得空間解析度與密度解析度的折衷；從窗函數的頻譜角度來講，可以用於圖像重建的一個良好的卷積窗函數應該具備以下條件： （ ? ）小的3db帶寬b ，即最小的主瓣寬度； （ ? ）最小的旁瓣最大峰值a ； （ ? ）最大的旁瓣峰值衰減速度d ；就內插函數而言，臨近點內插與線性內插重建圖像噪聲大，但有較好的邊緣與細節； 4 4三次內插、三次b -樣條與四次拉格朗日多項式內插圖像平滑，局部特性較好。Therefore the dynamical characteristic is acted as detected parameter for fractured detection ( primary amplitude secondary frequence ). and the amplitude of mean sguare and central frequence are acted as evaluational parameter, based on the those studies, the new ideas is put forward that fractured azimuth is dected by lateral difference and fractured density is dected by vertical difference for three facters of fracture, wavelet acted as analysis tool and direction by wave field characteristic applied the multiple scale edge dectection and self - adaptive edge detection into the detection theory of seismic fractured azimuth, also put forward the wavelet different scale filter method of the fractured azimuth detection
因而，確定了主要以振幅，其次是頻率的地震波動力學特徵作為裂縫檢測的被檢參數和均方振幅和中心頻率作為檢驗檢測結果正確與否的評價參數。在上述研究基礎上，針對裂縫的三要素，提出通過橫向求異檢測裂縫方位和縱向求異檢測裂縫密度的新思想。並以小波作為分析工具，以潛山波場特徵作指導，將數字圖像處理中的多尺度邊緣檢測和自適性邊緣檢測引用到地震裂縫方位檢測中來，並提出了小波變尺度濾波法新的裂縫方位檢測法。Image edge detection based on multiresolution wavelet transform makes up these shortages before. wavelet theory has good local inspect ability in time region and frequency region, and the character multiresolution. these are theory basis that wavelet transform is applied to cell image edge detection
小波變換是80年代後期發展起來的一種變換域信號處理方法，具有時域和頻域上良好的局部檢測能力和多解析度分析的特點，從而被譽為「數學顯微鏡」 ，這是我們將小波變換應用於細胞圖像邊緣檢測的理論依據。
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