當我們想要提取Region時，圖像處理后，往往存在幾個類似的Region，此時，需要根據Region的一些特殊特征，來選擇指定的Region。
求Region指定特征值：region_features(Regions : : Features : Value)
根據特征值選擇區域：select_shape(Regions : SelectedRegions : Features, Operation, Min, Max : )
Region特征一覽：
| 特征 | 英 | 譯 | 備注 |
| area | Area of the object | 對象的面積 | |
| row | Row index of the center | 中心點的行坐標 | |
| column | Column index of the center | 中心點的列坐標 | |
| width | Width of the region | 區域的寬度 | |
| height | Height of the region | 區域的高度 | |
| row1 | Row index of upper left corner | 左上角行坐標 | |
| column1 | Column index of upper left corner | 左上角列坐標 | |
| row2 | Row index of lower right corner | 右下角行坐標 | |
| column2 | Column index of lower right corner | 右下角列坐標 | |
| circularity | Circularity | 圓度 | 0~1 |
| compactness | Compactness | 緊密度 | 0~1 |
| contlength | Total length of contour | 輪廓線總長 | |
| convexity | Convexity | 凸性 | |
| rectangularity | Rectangularity | 矩形度 | 0~1 |
| ra | Main radius of the equivalent ellipse | 等效橢圓長軸半徑長度 | |
| rb | Secondary radius of the equivalent ellipse | 等效橢圓短軸半徑長度 | |
| phi | Orientation of the equivalent ellipse | 等效橢圓方向 | |
| anisometry | Anisometry | 橢圓參數，Ra/Rb長軸與短軸的比值 | |
| bulkiness | Bulkiness | 橢圓參數，蓬松度π*Ra*Rb/A | |
| struct_factor | Structur Factor | 橢圓參數，Anisometry*Bulkiness-1 | |
| outer_radius | Radius of smallest surrounding circle | 最小外接圓半徑 | |
| inner_radius | Radius of largest inner circle | 最大內接圓半徑 | |
| inner_width | Width of the largest axis-parallel rectangle that fits into the region | 最大內接矩形寬度 | |
| inner_height | Height of the largest axis-parallel rectangle that fits into the region | 最大內接矩形高度 | |
| dist_mean | Mean distance from the region border to the center | 區域邊界到中心的平均距離 | |
| dist_deviation | Deviation of the distance from the region border from the center | 區域邊界到中心距離的偏差 | |
| roundness | Roundness | 圓度，與circularity計算方法不同 | |
| num_sides | Number of polygon sides | 多邊形邊數 | |
| connect_num | Number of connection components | 連通數 | |
| holes_num | Number of holes | 區域內洞數 | |
| area_holes | Area of the holes of the object | 所有洞的面積 | |
| max_diameter | Maximum diameter of the region | 最大直徑 | |
| orientation | Orientation of the region | 區域方向 | |
| euler_number | Euler number | 歐拉數，即連通數和洞數的差 | |
| rect2_phi | Orientation of the smallest surrounding rectangle | 最小外接矩形的方向 | |
| rect2_len1 | Half the length of the smallest surrounding rectangle | 最小外接矩形長度的一半？？ | smallest_rectangle2 |
| rect2_len2 | Half the width of the smallest surrounding rectangle | 最小外接矩形寬度的一半 | |
| moments_m11 | Geometric moments of the region | 幾何矩 | |
| moments_m20 | Geometric moments of the region | 幾何矩 | |
| moments_m02 | Geometric moments of the region | 幾何矩 | |
| moments_ia | Geometric moments of the region | 幾何矩 | |
| moments_ib | Geometric moments of the region | 幾何矩 | |
| moments_m11_invar | Geometric moments of the region | 幾何矩 | |
| moments_m20_invar | Geometric moments of the region | 幾何矩 | |
| moments_m02_invar | Geometric moments of the region | 幾何矩 | |
| moments_phi1 | Geometric moments of the region | 幾何矩 | |
| moments_phi2 | Geometric moments of the region | 幾何矩 | |
| moments_m21 | Geometric moments of the region | 幾何矩 | |
| moments_m12 | Geometric moments of the region | 幾何矩 | |
| moments_m03 | Geometric moments of the region | 幾何矩 | |
| moments_m30 | Geometric moments of the region | 幾何矩 | |
| moments_m21_invar | Geometric moments of the region | 幾何矩 | |
| moments_m12_invar | Geometric moments of the region | 幾何矩 | |
| moments_m03_invar | Geometric moments of the region | 幾何矩 | |
| moments_m30_invar | Geometric moments of the region | 幾何矩 | |
| moments_i1 | Geometric moments of the region | 幾何矩 | |
| moments_i2 | Geometric moments of the region | 幾何矩 | |
| moments_i3 | Geometric moments of the region | 幾何矩 | |
| moments_i4 | Geometric moments of the region | 幾何矩 | |
| moments_psi1 | Geometric moments of the region | 幾何矩 | |
| moments_psi2 | Geometric moments of the region | 幾何矩 | |
| moments_psi3 | Geometric moments of the region | 幾何矩 | |
| moments_psi4 | Geometric moments of the region | 幾何矩 |