Buffer smaller than requested size for some LAS files about pylas HOT 6 CLOSED

This error is due to the header indicating a number of points that does not match the reality.

Do other softwares (lasinfo, cloudcompare, etc) manage to open the file without error or without
printing a warning ?

If you can seend a link with the file that would help the debug

from pylas.

Hi @tmontaigu,
thank you for your help.

I'm also sending the output of lasinfo:
`---------------------------------------------------------
Header Summary

Version: 1.2
Source ID: 0
Reserved: 0
Project ID/GUID: '00000000-0000-0000-0000-000000000000'
System ID: 'EXTRACTION'
Generating Software: 'LASfunctions v.1.0'
File Creation Day/Year: 156/2017
Header Byte Size 227
Data Offset: 2145
Header Padding: 0
Number Var. Length Records: 5
Point Data Format: 3
Number of Point Records: 2023834
Compressed: False
Number of Points by Return: 1505024 444251 69170 5187 201
Scale Factor X Y Z: 0.00025000000000 0.00025000000000 0.00025000000000
Offset X Y Z: 465864.0000 5060643.0000 355.0000
Min X Y Z: 465851.8133 5060638.0048 334.1078
Max X Y Z: 466398.7130 5060851.2268 374.3673
Spatial Reference:
Reference defined, but GDAL is not available for WKT support

Geotiff_Information:
Version: 1
Key_Revision: 1.0
Tagged_Information:
End_Of_Tags.
Keyed_Information:
GTModelTypeGeoKey (Short,1): ModelTypeProjected
GTRasterTypeGeoKey (Short,1): RasterPixelIsPoint
GTCitationGeoKey (Ascii,28): "WGS 84 / UTM zone 32N_ortho"
GeographicTypeGeoKey (Short,1): User-Defined
GeogCitationGeoKey (Ascii,6): "WGS84"
GeogGeodeticDatumGeoKey (Short,1): User-Defined
GeogPrimeMeridianGeoKey (Short,1): User-Defined
GeogLinearUnitsGeoKey (Short,1): Linear_Meter
GeogAngularUnitsGeoKey (Short,1): Angular_Degree
GeogEllipsoidGeoKey (Short,1): User-Defined
GeogSemiMajorAxisGeoKey (Double,1): 6378137
GeogInvFlatteningGeoKey (Double,1): 298.257223563
GeogAzimuthUnitsGeoKey (Short,1): Angular_Degree
GeogPrimeMeridianLongGeoKey (Double,1): 0
ProjectedCSTypeGeoKey (Short,1): User-Defined
PCSCitationGeoKey (Ascii,28): "WGS 84 / UTM zone 32N_ortho"
ProjectionGeoKey (Short,1): User-Defined
ProjCoordTransGeoKey (Short,1): CT_TransverseMercator
ProjLinearUnitsGeoKey (Short,1): Linear_Meter
ProjNatOriginLongGeoKey (Double,1): 9
ProjNatOriginLatGeoKey (Double,1): 0
ProjFalseEastingGeoKey (Double,1): 500000
ProjFalseNorthingGeoKey (Double,1): 0
ProjScaleAtNatOriginGeoKey (Double,1): 0.9996
VerticalUnitsGeoKey (Short,1): Linear_Meter
End_Of_Keys.
End_Of_Geotiff.

VLR Summary

User: 'LASF_Projection' - Description: 'GeoKeyDirectoryTag (mandatory)'
ID: 34735 Length: 208 Total Size: 262
User: 'LASF_Projection' - Description: 'GeoDoubleParamsTag (optional)'
ID: 34736 Length: 64 Total Size: 118
User: 'LASF_Projection' - Description: 'GeoASCIIParamsTag (optional)'
ID: 34737 Length: 62 Total Size: 116
User: 'LASF_Projection' - Description: 'OGC COORDINATE SYSTEM WKT'
ID: 2112 Length: 738 Total Size: 792
User: 'LASF_Spec' - Description: 'RIEGL Extra Bytes'
ID: 4 Length: 576 Total Size: 630

Schema Summary

Point Format ID: 3
Number of dimensions: 16
Custom schema?: false
Size in bytes: 34

Dimensions

'X' -- size: 32 offset: 0
'Y' -- size: 32 offset: 4
'Z' -- size: 32 offset: 8
'Intensity' -- size: 16 offset: 12
'Return Number' -- size: 3 offset: 14
'Number of Returns' -- size: 3 offset: 14
'Scan Direction' -- size: 1 offset: 14
'Flightline Edge' -- size: 1 offset: 14
'Classification' -- size: 8 offset: 15
'Scan Angle Rank' -- size: 8 offset: 16
'User Data' -- size: 8 offset: 17
'Point Source ID' -- size: 16 offset: 18
'Time' -- size: 64 offset: 20
'Red' -- size: 16 offset: 28
'Green' -- size: 16 offset: 30
'Blue' -- size: 16 offset: 32

Point Inspection Summary

Header Point Count: 2023834
Actual Point Count: 2023834

Minimum and Maximum Attributes (min,max)

Min X, Y, Z: 465851.8133, 5060638.0048, 334.1078
Max X, Y, Z: 466398.7130, 5060851.2268, 374.3673
Bounding Box: 465851.8133, 5060638.0048, 466398.7130, 5060851.2268
Time: 313666.295394, 313691.616049
Return Number: 1, 6
Return Count: 1, 6
Flightline Edge: 0, 0
Intensity: 0, 54197
Scan Direction Flag: 1, 1
Scan Angle Rank: -43, 9
Classification: 2, 3
Point Source Id: 0, 0
User Data: 0, 0
Minimum Color (RGB): 0 1024 0
Maximum Color (RGB): 65280 65280 65280

Number of Points by Return

(1) 1505024	(2) 444251	(3) 69170	(4) 5187	(5) 201	(6) 1

Number of Returns by Pulse

(1) 1035210	(2) 762013	(3) 203503	(4) 21983	(5) 1115	(6) 10

Point Classifications

243759 Ground (2) 
1780075 Low Vegetation (3) 

0 withheld
0 keypoint
0 synthetic

`

I'd like to add that I'm able to read this las file with libLAS library without problems.

I hope these infos help identifying the problem.
Thank you for helping

pm

from pylas.

The problem comes from the fact that in the LAS header the point size is said to be 34 (the point size for a LAS with point format 3 and no extra bytes) but there is also an Extra bytes vlr present in the file:

lasinfo reports

variable length header record 5 of 5:
  reserved             43707
  user ID              'LASF_Spec'
  record ID            4
  length after header  576
  description          'RIEGL Extra Bytes'
    Extra Byte Descriptions
      data type: 3 (unsigned short), name "Amplitude", description: "Echo signal amplitude [dB]", min: 0, max: 10000, scale: 0.01, offset: 0 (not set)

      data type: 4 (short), name "Reflectance", description: "Echo signal reflectance [dB]", min: -5000, max: 15000, scale: 0.01, offset: 0 (not set)

      data type: 3 (unsigned short), name "Deviation", description: "Pulse shape deviation", min: 0, max: 32767, scale: 1 (not set), offset: 0 (not set)

which brings the point_size to 40 bytes.
The files has 2_023_834 points and is 68_812_501 bytes on disk.

2_023_834 * 40 = ‭‭80,953,360‬ bytes
2_023_834 * 34 = ‭68,810,356‬ bytes

Do you expect the fields 'Amplitude', 'Reflectance', 'Deviation' to be in that particular file ?

from pylas.

Thank you very much for the explanation!
The fact is that I just need to read the points from the file; I don't need those fields (amplitude, reflectance, deviation) to be considered for the data extraction I'm going to do.

Is there a way to be able to get all the points anyway?

Thank you again,

pm

from pylas.

Well you can either reinstall pylas from github since i pushed a commit that fixes this, or wait for a new release.
or you could use lastools' las2las to remove the wrong vlr

las2las -remove_vlr 4 -i pointcloud.las -o pointcloud_without_extra_bytes_vlr.las

from pylas.

Wow, perfect! Thanks for the quick responses and fix :)

from pylas.