紋理特徵三:GLSZM–灰度區域大小矩陣
1. GLSZM 的解釋與計算
GLSZM,全稱gray-level size zone matrix,中文名稱弧度區域大小矩陣。
概念描述: GLSZM與GLRLM(gray-level run-length matrix)類似,GLRLM是在一維方向上記錄連續j j j 個像素值i i i 連續相鄰的情況的出現的次數,GLSZM是在二維區域內記錄圖像區域內有j j j 個i i i 元素相鄰的情況的出現的次數。
舉例如下:
下圖來自網址:這裏
2.GLRLM計算得到的紋理特徵
像素值(灰度值)爲i i i ,連續相鄰數j j j ,角度值(方向)爲θ \theta θ ,p ( i , j ∣ θ ) p(i,j|\theta) p ( i , j ∣ θ ) 爲在θ \theta θ 方向上連續j j j 個i i i 值的情況的個數或概率(用頻率近似概率)。
則有
1.Short Zone Emphasis(SZE)
S Z E = ∑ i ∑ j [ p ( i , j j 2 ] ∑ i ∑ j p ( i , j ) SZE=\frac{\sum_i\sum_j[\frac{p(i,j}{j^2}]}{\sum_i\sum_jp(i,j)} S Z E = ∑ i ∑ j p ( i , j ) ∑ i ∑ j [ j 2 p ( i , j ]
2.Long Zone Emphasis(LZE)
L Z E = ∑ i ∑ j j 2 p ( i , j ) ∑ i ∑ j p ( i , j ) LZE=\frac{\sum_i\sum_jj^2p(i,j)}{\sum_i\sum_jp(i,j)} L Z E = ∑ i ∑ j p ( i , j ) ∑ i ∑ j j 2 p ( i , j )
3.Gray Level Non_Uniformity(GLN)
G L N = ∑ i [ ∑ j p ( i , j ) ] 2 ∑ i ∑ j p ( i , j ) GLN=\frac{\sum_i[\sum_jp(i,j)]^2}{\sum_i\sum_jp(i,j)} G L N = ∑ i ∑ j p ( i , j ) ∑ i [ ∑ j p ( i , j ) ] 2
4.Zone-Size Non_Uniformity(RLN)
Z S N = ∑ j [ ∑ i p ( i , j ) ] 2 ∑ i ∑ j p ( i , j ) ZSN=\frac{\sum_j[\sum_ip(i,j) ]^2}{\sum_i\sum_jp(i,j)} Z S N = ∑ i ∑ j p ( i , j ) ∑ j [ ∑ i p ( i , j ) ] 2
5.Zone Percentage(ZP)
Z P = ∑ i ∑ j p ( i , j ) N p ZP=\sum_i\sum_j\frac{p(i,j)}{N_p} Z P = i ∑ j ∑ N p p ( i , j )
N p N_p N p 是GLZSM中元素個數
6.Low Gray Level Zone Emphasis(LGZE)
L G Z E = ∑ i ∑ j [ p ( i , j ) i 2 ] ∑ i ∑ j p ( i , j ) LGZE=\frac{\sum_i\sum_j[\frac{p(i,j)}{i^2}]}{\sum_i\sum_jp(i,j)} L G Z E = ∑ i ∑ j p ( i , j ) ∑ i ∑ j [ i 2 p ( i , j ) ]
7.High Gray Level Zone Emphasis(HGZE)
H G Z E = ∑ i ∑ j i 2 p ( i , j ) ∑ i ∑ j p ( i , j ) HGZE=\frac{\sum_i\sum_ji^2p(i,j)}{\sum_i\sum_jp(i,j)} H G Z E = ∑ i ∑ j p ( i , j ) ∑ i ∑ j i 2 p ( i , j )
8.Small Zone Low Gray Level Emphasis(SZLGLE)
S Z L G L E = ∑ i ∑ j [ p ( i , j ) i 2 j 2 ] ∑ i ∑ j p ( i , j ) SZLGLE=\frac{\sum_i\sum_j[\frac{p(i,j)}{i^2j^2}]}{\sum_i\sum_jp(i,j)} S Z L G L E = ∑ i ∑ j p ( i , j ) ∑ i ∑ j [ i 2 j 2 p ( i , j ) ]
9.Small Run High Gray Level Emphasis(SZHGLE)
S Z H G L E = ∑ i ∑ j [ i 2 p ( i , j ) j 2 ] ∑ i ∑ j p ( i , j ) SZHGLE=\frac{\sum_i\sum_j[\frac{i^2p(i,j)}{j^2}]}{\sum_i\sum_jp(i,j)} S Z H G L E = ∑ i ∑ j p ( i , j ) ∑ i ∑ j [ j 2 i 2 p ( i , j ) ]
10.Large Zone Low Gray Level Emphasis(LZLGLE)
L Z L G L E = ∑ i ∑ j [ j 2 p ( i , j ) i 2 ] ∑ i ∑ j p ( i , j ) LZLGLE=\frac{\sum_i\sum_j[\frac{j^2p(i,j)}{i^2}]}{\sum_i\sum_jp(i,j)} L Z L G L E = ∑ i ∑ j p ( i , j ) ∑ i ∑ j [ i 2 j 2 p ( i , j ) ]
11.Large Zone High Gray Level Emphasis(LZHGLE)
L Z H G L E = ∑ i ∑ j i 2 j 2 p ( i , j ) ∑ i ∑ j p ( i , j ) LZHGLE=\frac{\sum_i\sum_ji^2j^2p(i,j)}{\sum_i\sum_jp(i,j)} L Z H G L E = ∑ i ∑ j p ( i , j ) ∑ i ∑ j i 2 j 2 p ( i , j )
12.Gray-Level Variance (GLV)
13.Run-Length Variance (RLV)