Masson pine (Pinus massoniana (Lamb.), 85), Chinese fir (Cunninghamia lanceolate (Lamb.), 82), Slash pines (Pinus elliottii Engelm., 71), Sawtooth oak (Querus acutissima Carruth., 73), Chinese sweet gum (Liquidambar formosana Hance, 74), Chinese holly (Ilex chinensis Sims., 52) [Yushan Forest, China, leaf-on] | Local Maxima Algorithm on CHM; Random Forest with Mean Decrease Accuracy [2/3 for model training] | ΔWRcentroid,ground, ΔWRbeginning,ground, ΔWRbeginning,1stpeak, TNowave,stats, FS, RWE | c: 86.2% | [15] |
s: 68.6% |
Red pine (Pinus koraiensis), Koyama spruce (Picea koraiensis), Dahurian larch (Larix gmelinii), fir (Abies nephrolepis), white birch (Betula platyphylla Suk.), ribbed birch (Betula Costata), Manchurian linden (Tilia Mandschurica), elm (Ulmus Laciniata), Mongolian oak (Quercus Mongolica); (in total: 1847 trees) [Forest, China, leaf-on] | Watershed Segmentation on CHM; Support Vector Machine | Range corrected Astats,obj, EAWstats,obj, EWstats,obj, TNostats,ob | c: 85.7% | [24] |
s: 55.1% |
Scots pine (Pinus sylvestris), Norway spruce (Picea abies), sessile oak (Quercus petraea), red oak (Quercus rubra), European beech (Fagus sylvatica) [Forest, SW Germany, leaf-on] | Linear Discriminant Analysis with 18-fold cross-validation | Astats,obj, EAWstats,obj, EWstats,obj, TNostats,ob | c: 91.7% | [25] |
s: 80.4% |
Spruce (Picea abies, 42), European larch (Larix decidua, 23), red beech (Fagus sylvatica, 76) [Forest, Austria, leaf-off] | Edge-based segmentation on nDSM; FuzzyRule Set & Decision Tree [1/2 for model training] | ER3D/2D, TNoHmin, EWmean, EWstddev, σmean, σstdev, Hmin > 50th height | c: 83% | [26] |
s: 75% |
Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies (L.) Karst.), birches (Betula pendula Roth and Betula pubescens Ehrh.); (in total: 9930 trees) [Forest, Hyytiälä, Finland, leaf-on] | Watershed segmentation on CHM & delineation by cylinders; Quadratic Discriminant Analysis and leave-one-out cross validation | Astats, FWHMstats, RWE, Hm,50%energy, pulse length | 84%–91% | [27] |
Red beech (Fagus sylvatica, 11), oaks (Quercus robur and Quercus petraea, 10), hornbeam, larch (Carpinus betulus, 4) [Vienna Woods, Austria, leaf-off] | Edge-based segmentation on nDSM; Descriptive feature analysis | EWmean, EWCV, σmean, σcv | (exploratory analysis) | [47] |
Norway spruce (Picea abies, 256), European beech (Fagus sylvatica, 397), Sycamore maple (Acer pseudoplatanus, 20) [Mountainous, mixed forest, SE Germany] | Watershed segmentation on CHM; k-Means clustering | leaf-on: ΔDtrunk dist, horiz., EAWobj,mean, EW mean_single, EW mean_first leaf-off: EWsingle, EWfirst, ERsingle/multiple | c: | [52] |
leaf-on: 85.4% |
leaf-off: 95.7% |
Norway spruce (Picea abies, 688), European beech (Fagus sylvatica, 812), fir (Abies alba, 70), Sycamore maple (Acer pseudoplatanus, 71), Norway maple (Acer platanoides, 21), lime trees (Tilia Europaea, 2) [Mountainous, mixed forest, SE Germany] | Normalized cut segmentation; Expectation-Maximization Algorithm & Maximum Likelihood Classification [1/5 for model training] | ΔDtrunk dist,horiz., EAWobj,mean, EWmean_single, EWmean_first, ERsingle/multiple | c: | [53] |
leaf-on: 95/97% |
leaf-off: 94% |
Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), western redcedar (Thuja plicata Donn ex D.Don), black cottonwood (Populus balsamifera L. ssp. trichocarpa (Torr. & A. Gray ex Hook.) Brayshaw), bigleaf maple (Acer macrophyllum Pursh), red alder (Alnus rubra Bong.); (22 to 29 trees per species) [Arboretum, Seattle, USA, leaf-on] | Voxel-based segmentation; Support Vector Machine with five-fold cross-validation | Vstats, ΔRij, EAWmean, Pstats,perc, TNostats, PCwave,Fourier | s: 85.4% | [55] |
Norway spruce (Picea abies, 688), European beech (Fagus sylvatica, 812), fir (Abies alba, 70), Sycamore maple (Acer pseudoplatanus, 71), Norway maple (Acer platanoides, 21), lime trees (Tilia Europaea, 2) [Mountainous, mixed forest, SE Germany] | Watershed segmentation & Normalized cut segmentation; Expectation Maximization Algorithm & Maximum Likelihood | Pstats,perc, Astats, EAWstats, EWstats, filtered by the index of return | c: | [66] |
leaf-on: 95% |
leaf-off: 94% |
lower layers: |
leaf-on: 86% |
leaf-off: 95% |
upper layers: |
leaf-on: 97% |
leaf-off: 94% |
Jack pine (Pinus banksiana Lamb., 158), eastern white pine (Pinus strobus L., 106), sugar maple (Acer saccharum Marsh., 105), trembling aspen (Populus tremuloides Michx., 182) [Forest, Ontario, Canada, leaf-on] | Individual tree crown delineation from optical imagery; Linear Discriminant Analysis with 10-fold cross validation [1/2 for model training] | Pgrid,VTMR, Pdens,L-func, PTIN,Edge | c: 82.2% | [67] |
s: 77.5% |
Norway spruce (Picea abies (L.)), Scots pine (Pinus sylvestris, (L.)), birches (Betula pendula (L.) and Betula pubescens (L.)); (in total, 789 trees) [Forest, SW Sweden, leaf-on] | 3D ellipsoid clustering; Linear Discriminant Analysis with leave-one-out cross validation | Astats,obj, EAWstats,obj, EWstats,obj, TNostats, Zobj_ellip, PSheight, PSradius | s: 71% | [73] |
Scots pine (Pinus sylvestris), Norway spruce (Picea abies), birch (Betula sp.); (in total, 3695) [Forest, South Finland, leaf-on] | Minimum curvature-based region detector; Random Forest with cross validation | ΔR1st/last, RWE, TNo, A1st/2nd/rd/th, Hm,energy | s: 71.5% | [76] |
Norway spruce (Picea abies (L.), 209), birch (Betula spp., 203), aspen (Poplus tremula L.) [Forest, SE Norway, leaf-on] | Mean crown radius; Linear Discriminant Analysis & ANCOVA with cross-validation | VH_kurtosis, VH_skewness, VH_coeff.var., Aobj,mean, Aobj,max, Pdens,bin | s: 88% | [97] |