matlab PHASECONG3函数解析

大佬网站的链接：PHASECONG3

这个函数是用来计算图像的边缘和角的相位一致性

下面是该函数的注释
This function calculates the PC_2 measure of phase congruency.
PC_2就是相位一致性
This function supersedes PHASECONG2 and PHASECONG being faster and requires
less memory
第三版，比前两版更快，内存更少
There are potentially many arguments, here is the full usage:
有很多潜在参数，下面是完整用法
[M m or ft pc EO, T] = phasecong3(im, nscale, norient, minWaveLength, mult, sigmaOnf, k, cutOff, g, noiseMethod)

However, apart from the image, all parameters have defaults and the usage can be as simple as:
除了image，其他都不是必须的
M = phasecong3(im);

Arguments Default values Description

nscale           4    - Number of wavelet scales, try values 3-6，小波数量，默认4
norient          6    - Number of filter orientations. 过滤器方向的数量
minWaveLength    3    - Wavelength of smallest scale filter.最小尺度的滤波器波长
mult             2.1  - Scaling factor between successive filters.连续滤波器之间的比例因子
sigmaOnf         0.55 - Ratio of the standard deviation of the Gaussian describing the log Gabor filter's transfer function in the frequency domain to the filter center frequency.描述对数Gabor滤波器传递函数的高斯函数在频域上的标准差与滤波器中心频率的比值。
k                2.0  - No of standard deviations of the noise energy beyondthe mean at which we set the noise threshold point.You may want to vary this up to a value of 10 or20 for noisy images噪声能量超过我们设定的噪声阈值点的平均值的标准偏差。
cutOff           0.5  - The fractional measure of frequency spreadbelow which phase congruency values get penalized.频率扩展的分数度量，低于它的相位一致性值会受到惩罚
g                10   - Controls the sharpness of the transition inthe sigmoid function used to weight phasecongruency for frequency spread.  控制sigmoid函数中转换的锐度，用于加权频率扩展的相位一致性。
noiseMethod      -1   - Parameter specifies method used to determinenoise statistics. -1 use median of smallest scale filter responses-2 use mode of smallest scale filter responses0+ use noiseMethod value as the fixed noise threshold 参数指定用于确定噪声统计的方法。

Returned values:
M - Maximum moment of phase congruency covariance.
This is used as a indicator of edge strength.
相位一致性协方差的最大矩。这被用作边缘强度的指标。
m - Minimum moment of phase congruency covariance.
This is used as a indicator of corner strength.
相位一致性协方差的最小矩。这被用作拐角强度的指标。
or - Orientation image in integer degrees 0-180,
positive anticlockwise.
0 corresponds to a vertical edge, 90 is horizontal.
图像方位范围在0-180度，逆时针为正方向。0对应垂直边，90对应水平边。
ft - Local weighted mean phase angle at every point in the
image. A value of pi/2 corresponds to a bright line, 0
corresponds to a step and -pi/2 is a dark line.
图像中每一点的局部加权平均相位角。/2的值对应一条亮线，0对应一个阶跃，- /2是一条暗线
pc - Cell array of phase congruency images (values between 0 and 1)
for each orientation
每个方向的相位一致性图像(值在0和1之间)的单元阵列
EO - A 2D cell array of complex valued convolution result
一个复值卷积结果的二维单元数组
T - Calculated noise threshold (can be useful for
diagnosing noise characteristics of images). Once you know
this you can then specify fixed thresholds and save some
computation time.
计算噪声阈值(可用于诊断图像的噪声特征)。一旦您知道了这一点，您就可以指定固定的阈值并节省一些计算时间。

EO{s,o} = convolution result for scale s and orientation o. The real part
is the result of convolving with the even symmetric filter, the imaginary
part is the result from convolution with the odd symmetric filter.
卷积结果是{刻度s,方向o}，实部是与偶对称滤波器卷积的结果，虚部是与奇对称滤波器卷积的结果

Hence:
abs(EO{s,o}) returns the magnitude of the convolution over the
image at scale s and orientation o.
angle(EO{s,o}) returns the phase angles.
因此abs(EO{s,o})返回在尺度s和方向o的图像上卷积的大小。angle(EO{s,o})返回相位角。

Notes on specifying parameters:

The parameters can be specified as a full list eg.

[M m or ft pc EO] = phasecong3(im, 5, 6, 3, 2.5, 0.55, 2.0, 0.4, 10);

or as a partial list with unspecified parameters taking on default values

[M m or ft pc EO] = phasecong3(im, 5, 6, 3);

or as a partial list of parameters followed by some parameters specified via a
keyword-value pair, remaining parameters are set to defaults, for example:

[M m or ft pc EO] = phasecong3(im, 5, 6, 3, ‘cutOff’, 0.3, ‘k’, 2.5);

The convolutions are done via the FFT. Many of the parameters relate to the
specification of the filters in the frequency plane. The values do not seem
to be very critical and the defaults are usually fine. You may want to
experiment with the values of ‘nscales’ and ‘k’, the noise compensation factor.
卷积是通过FFT完成的。许多参数与频率平面滤波器的规格有关。这些值似乎不是很重要，缺省值通常都很好。你可以用“nscales”和“k”的值做实验，这是噪声补偿因子。

Notes on filter settings to obtain even coverage of the spectrum
sigmaOnf .85 mult 1.3
sigmaOnf .75 mult 1.6 (filter bandwidth ~1 octave)
sigmaOnf .65 mult 2.1
sigmaOnf .55 mult 3 (filter bandwidth ~2 octaves)

See Also: PHASECONG, PHASECONG2, PHASESYM, GABORCONVOLVE, PLOTGABORFILTERS

matlab PHASECONG3函数解析相关推荐

matlab newff函数解析
matlab newff函数解析 newff Syntax Description Examples Algorithm 传递函数TFi 学习训练函数BTF 参数说明 see:http://matla ...
MATLAB filter函数解析
现在正在学习MATLAB信号处理方面的应用,程序中遇到filter函数,从网上查阅资料,我能找到的资料感觉写的也是模棱两可,不易使人明白,所以就花了一下午的时间好好研究了下,终于知道这个函数的使用方法 ...
Matlab bsxfun函数解析
bsxfun是一个matlab自版本R2007a来就提供的一个函数,作用是"applies an element-by-element binary operation to arrays ...
matlab butter()函数解析
butter函数是求Butterworth数字滤波器的系数: [B,A]=butter(n,wn) n是滤波器的阶数,根据需要选择合适的整数,Wn是归一化截止频率,又叫自然频率,Wn = 截止频率*2 ...
matlab atan2函数解析
旁边的图片显示内容是:在一个单位圆内atan2函数在各点的取值.圆内标注代表各点的取值的幅度表示. 图片中,从最左端开始,角度的大小随着逆时针方向逐渐从-π增大到+π,并且角度大小在点位于最右端时,取 ...
matlab中dist的命令,matlab dist函数
dist--欧式距离加权函数(Euclidean distance weight function) 语法: Z = dist(W,P) df = dist('deriv') D = dist(pos ...
Matlab中bsxfun和unique函数解析
一.问题来源来自于一份LSH代码,记录下来. 二.函数解析 2.1 bsxfun bsxfun是一个matlab自版本R2007a来就提供的一个函数,作用是"applies an elem ...
matlab中emd函数,EMD算法的matlab程序介绍解析
<EMD算法的matlab程序介绍解析>由会员分享,可在线阅读,更多相关<EMD算法的matlab程序介绍解析(6页珍藏版)>请在人人文库网上搜索. 1.此版本为 ALAN 版 ...
rectpuls函数 matlab,Matlab中的rectpuls函数解析
Matlab中的rectpuls函数解析 Matlab中的rectpuls函数解析 1.先看Matlab中的解释: This MATLAB function returns a continuous, ...

matlab PHASECONG3函数解析

matlab PHASECONG3函数解析相关推荐

最新文章

热门文章