zoukankan      html  css  js  c++  java
  • matlab中fspecial函数

    fspecial函数

    用于建立预定义的滤波算子,其语法格式为:
    h = fspecial(type)
    h = fspecial(type,para)
    其中type指定算子的类型,para指定相应的参数;

    2type的类型有

    'average'

    averaging filter
    为均值滤波,参数为hsize代表模板尺寸,默认值为[3,3]。
    H = FSPECIAL('average',HSIZE) returns an averaging filter H of size
    HSIZE. HSIZE can be a vector specifying the number of rows and columns in
    H or a scalar, in which case H is a square matrix.
    The default HSIZE is [3 3].

    'disk'

    circular averaging filter
    为圆形区域均值滤波,参数为radius代表区域半径,默认值为5.
    H = FSPECIAL('disk',RADIUS) returns a circular averaging filter
    (pillbox) within the square matrix of side 2*RADIUS+1.
    The default RADIUS is 5.

    'gaussian'

    Gaussian lowpass filter
    为高斯低通滤波,有两个参数,hsize表示模板尺寸,默认值为[3 3],sigma为滤波器的标准值,单位为像素,默认值为0.5.
    H = FSPECIAL('gaussian',HSIZE,SIGMA) returns a rotationally
    symmetric Gaussian lowpass filter
    of size HSIZE with standard
    deviation SIGMA (positive). HSIZE can be a vector specifying the
    number of rows and columns in H or a scalar, in which case H is a
    square matrix.
    The default HSIZE is [3 3], the default SIGMA is 0.5.

    'laplacian'

    filter approximating the 2-D Laplacian operator
    为拉普拉斯算子,参数alpha用于控制算子形状,取值范围为[0,1],默认值为0.2.
    H = FSPECIAL('laplacian',ALPHA) returns a 3-by-3 filter
    approximating the shape of the two-dimensional Laplacian
    operator. The parameter ALPHA controls the shape of the
    Laplacian and must be in the range 0.0 to 1.0.
    The default ALPHA is 0.2.

    'log'

    Laplacian of Gaussian filter
    为拉普拉斯高斯算子,有两个参数,hsize表示模板尺寸,默认值为[3 3],sigma为滤波器的标准差,单位为像素,默认值为0.5.
    H = FSPECIAL('log',HSIZE,SIGMA) returns a rotationally symmetric
    Laplacian of Gaussian filter of size HSIZE with standard deviation
    SIGMA (positive). HSIZE can be a vector specifying the number of rows
    and columns in H or a scalar, in which case H is a square matrix.
    The default HSIZE is [5 5], the default SIGMA is 0.5.

    'motion'

    motion filter
    为运动模糊算子,有两个参数,表示摄像物体逆时针方向以theta角度运动了len个像素,len的默认值为9,theta的默认值为0;
    H = FSPECIAL('motion',LEN,THETA) returns a filter to approximate, once
    convolved with an image, the linear motion of a camera by LEN pixels,
    with an angle of THETA degrees in a counter-clockwise direction. The
    filter becomes a vector for horizontal and vertical motions.
    The
    default LEN is 9, the default THETA is 0, which corresponds to a
    horizontal motion of 9 pixels.

    'prewitt'

    Prewitt horizontal edge-emphasizing filter
    用于边缘增强,大小为[3 3],无参数
    H = FSPECIAL('prewitt') returns 3-by-3 filter that emphasizes
    horizontal edges by approximating a vertical gradient. If you need to
    emphasize vertical edges, transpose the filter H: H'.
    [1 1 1;0 0 0;-1 -1 -1].

    'sobel'

    Sobel horizontal edge-emphasizing filter
    用于边缘提取,无参数
    H = FSPECIAL('sobel') returns 3-by-3 filter that emphasizes
    horizontal edges utilizing the smoothing effect by approximating a
    vertical gradient. If you need to emphasize vertical edges, transpose
    the filter H: H'.
    [1 2 1;0 0 0;-1 -2 -1].

    'unsharp'

    unsharp contrast enhancement filter
    为对比度增强滤波器。参数alpha用于控制滤波器的形状,范围为[0,1],默认值为0.2
  • 相关阅读:
    4级搭建类403-Oracle 12cR2 DG 搭建(WinServer 2019 一对一 LGWR ASYNC CDB模式)
    4级搭建类402-Oracle 11gR2 DG搭建(WinServer 2019 一对一 LGWR ASYNC)
    12c OCP考试专项 [1z0-071]-Q23: alias别名的使用(2020.06.21)
    12c OCP考试专项 [1z0-071]-Q22: 小计合计(2020.06.18)
    12c OCP考试专项 [1z0-071]-Q21: 日期返回格式(2020.06.18)
    12c OCP考试专项 [1z0-071]-Q20: 集合操作符(2020.06.18)
    12c OCP考试专项 [1z0-071]-Q19: 升序降序/最大值排序(2020.06.18)
    12c OCP考试专项 [1z0-071]-Q18: IS NOT NULL 查询空值及 DISTINCT 去重用法(2020.06.18)
    12c OCP考试专项 [1z0-071]-Q17: 对象权限的授权(2020.06.18)
    12c OCP考试专项 [1z0-071]-Q16: 对象权限的授权(2020.06.18)
  • 原文地址:https://www.cnblogs.com/snowxshy/p/3850270.html
Copyright © 2011-2022 走看看