I also ran some benchmarks on laz and yes, MG4. I'd like to be able to collaborate with some of you on this effort. I think MPG's comments about the different target workflows are spot on. For now, I do have an interesting observation about LAS and LAZ: in both cases there seems to be a linear relationship between the cropped area the time it takes to do the extraction. That would be expected if either
(a) there was some indexing support that told us where in the file the points were. But I don't believe there is any. (b) The process was dominated by output latency. But I'm not creating output (specifying "-o -" ... which is what that's for I assume) Absent either of those factors I would have expected the extraction time to be roughly constant ... a full scan through the file and pick out the points we care about. So, why is it doing this? In both graphs, Y is time in seconds. In the first graph, X is the fraction of the total file cropped out. In the second, X is the number of points actually extracted. [cid:[email protected]] [cid:[email protected]] To test, I installed OSGeo4W and ran las2las on increasingly large crop areas from the center of MtStHelens.laz and .las (I encoded my own, but sample are available from http://liblas.org/samples. Here's the script I used: TimeThis las2las -e 1210343.88937174,315410.054252848,1215428.96062826,323308.825747152 -i MtStHelens.las -o - TimeThis las2las -e 1209290.7366317,313774.165113335,1216482.1133683,324944.714886665 -i MtStHelens.las -o - TimeThis las2las -e 1208482.6241118,312518.903227245,1217290.2258882,326199.976772755 -i MtStHelens.las -o - TimeThis las2las -e 1207801.35374348,311460.668505697,1217971.49625652,327258.211494303 -i MtStHelens.las -o - TimeThis las2las -e 1207201.1425,310528.345,1218571.7075,328190.535 -i MtStHelens.las -o - TimeThis las2las -e 1206658.51005792,309685.460122058,1219114.33994208,329033.419877942 -i MtStHelens.las -o - TimeThis las2las -e 1206159.50802811,308910.347481574,1219613.34197189,329808.532518426 -i MtStHelens.las -o - TimeThis las2las -e 1205695.0482634,308188.89022667,1220077.8017366,330529.98977333 -i MtStHelens.las -o - TimeThis las2las -e 1205258.81811523,307511.282758545,1220514.03188477,331207.597241455 -i MtStHelens.las -o - TimeThis las2las -e 1204846.22138258,306870.385680395,1220926.62861742,331848.494319605 -i MtStHelens.las -o - TimeThis las2las -e 1204453.78830496,306260.80932432,1221319.06169504,332458.07067568 -i MtStHelens.las -o - TimeThis las2las -e 1204078.82322361,305678.36645449,1221694.02677639,333040.51354551 -i MtStHelens.las -o - TimeThis las2las -e 1203719.18242262,305119.727182058,1222053.66757738,333599.152817942 -i MtStHelens.las -o - TimeThis las2las -e 1203373.12778539,304582.19164595,1222399.72221461,334136.68835405 -i MtStHelens.las -o - TimeThis las2las -e 1203039.22685462,304063.534773533,1222733.62314538,334655.345226467 -i MtStHelens.las -o - TimeThis las2las -e 1202716.28248697,303561.897011393,1223056.56751303,335156.982988607 -i MtStHelens.las -o - TimeThis las2las -e 1202403.2820478,303075.705408185,1223369.5679522,335643.174591815 -i MtStHelens.las -o - TimeThis las2las -e 1202099.3598951,302603.615340005,1223673.4901049,336115.264659995 -i MtStHelens.las -o - TimeThis las2las -e 1201803.76913607,302144.466639106,1223969.08086393,336574.413360894 -i MtStHelens.las -o - TimeThis las2las -e 1201515.86,301697.25,1224256.99,337021.63 -i MtStHelens.las -o -
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