Memory limit issues with r.univar (when used within i.segment.stats)

[jpduffy]

Hello,

I am trying to use i.segment.stats as part of an OBIA workflow on high resolution raster orthomosaics. So far I have used i.segment.uspo, i.segment and r.clump to create a layer called gp_seg_optimum_clump. Using r.clump means that the clumps are sequentially numbered, whereas they are not directly after i.segment.

I try to run the following command:

i.segment.stats --overwrite --verbose map=gp_seg_optimum_clump@gp1 \
rasters=gp_ortho.1@gp1,gp_ortho.2@gp1,gp_ortho.3@gp1,gp_ortho.4@gp1 \
raster_statistics=min,max,mean,stddev,variance,sum \
csvfile=/home/jpd205/Wales_GRASS/GarronPill/gp_seg_stats \
separator=comma

And I get the following error:

Calculating geometry statistics
Calculating statistics for raster gp_ortho.1@gp1
ERROR: G_realloc: unable to allocate 572000 bytes of memory at
       raster/r.univar/r.univar_main.c:324
Traceback (most recent call last):
  File "/home/jpd205/.grass7/addons/scripts/i.segment.stats", line 251, in <module>
    main()
  File "/home/jpd205/.grass7/addons/scripts/i.segment.stats", line 176, in main
    quiet=True)
  File "/usr/lib/grass70/etc/python/grass/script/core.py", line 395, in run_command
    return handle_errors(returncode, returncode, args, kwargs)
  File "/usr/lib/grass70/etc/python/grass/script/core.py", line 313, in handle_errors
    returncode=returncode)
grass.exceptions.CalledModuleError: Module run None ['r.univar', '--o', '--q', '-et', 'zones=gp_seg_optimum_clump@gp1', 'output=/home/jpd205/Wales_GRASS/GarronPill/gp1/.tmp/osgeobeefy/6462.0', 'map=gp_ortho.1@gp1'] ended with error
Process ended with non-zero return code 1. See errors in the (error) output.

Some details about my region settings and data:

g.region -p
projection: 99 (OSGB 1936 / British National Grid)
zone:       0
datum:      osgb36
ellipsoid:  airy
north:      208007.00931776
south:      207952.59780698
west:       200993.90853302
east:       201097.28911076
nsres:      0.00430914
ewres:      0.00430914
rows:       12627
cols:       23991
cells:      302934357

r.info map=gp_seg_optimum_clump
 +----------------------------------------------------------------------------+
 | Map:      gp_seg_optimum_clump           Date: Thu Oct 27 14:28:30 2016    |
 | Mapset:   gp1                            Login of Creator: jpd205          |
 | Location: GarronPill                                                       |
 | DataBase: /home/jpd205/Wales_GRASS                                         |
 | Title:    gp_seg_optimum_clump ( gp_seg_optimum_clump )                    |
 | Timestamp: none                                                            |
 |----------------------------------------------------------------------------|
 |                                                                            |
 |   Type of Map:  raster               Number of Categories: 0               |
 |   Data Type:    CELL                                                       |
 |   Rows:         12627                                                      |
 |   Columns:      23991                                                      |
 |   Total Cells:  302934357                                                  |
 |        Projection: OSGB 1936 / British National Grid                       |
 |            N: 208007.00931776    S: 207952.59780698   Res: 0.00430914      |
 |            E: 201097.28911076    W: 200993.90853302   Res: 0.00430914      |
 |   Range of data:    min = 1  max = 1264957                                 |
 |                                                                            |
 |   Data Source:                                                             |
 |    gp_seg_optimum@gp1                                                      |
 |                                                                            |
 |                                                                            |
 |   Data Description:                                                        |
 |    generated by r.clump                                                    |
 |                                                                            |
 |   Comments:                                                                |
 |    r.clump --overwrite --verbose -d input="gp_seg_optimum@gp1" output="\   |
 |    gp_seg_optimum_clump" title="gp_seg_optimum_clump"                      |
 |                                                                            |
 +----------------------------------------------------------------------------+

r.info map=gp_ortho.1
 +----------------------------------------------------------------------------+
 | Map:      gp_ortho.1                     Date: Mon Oct 17 09:06:32 2016    |
 | Mapset:   gp1                            Login of Creator: jd              |
 | Location: GarronPill                                                       |
 | DataBase: /home/jpd205/Wales_GRASS                                         |
 | Title:     ( gp_ortho.1 )                                                  |
 | Timestamp: none                                                            |
 |----------------------------------------------------------------------------|
 |                                                                            |
 |   Type of Map:  raster               Number of Categories: 0               |
 |   Data Type:    CELL                                                       |
 |   Rows:         12627                                                      |
 |   Columns:      23991                                                      |
 |   Total Cells:  302934357                                                  |
 |        Projection: OSGB 1936 / British National Grid                       |
 |            N: 208007.00931776    S: 207952.59780698   Res: 0.00430914      |
 |            E: 201097.28911076    W: 200993.90853302   Res: 0.00430914      |
 |   Range of data:    min = 0  max = 255                                     |
 |                                                                            |
 |   Data Description:                                                        |
 |    generated by r.in.gdal                                                  |
 |                                                                            |
 |   Comments:                                                                |
 |    r.in.gdal -o input="/home/jd/GarronPill_R_BNG_PS2_O_C_RGB_TEX.tif" o\   |
 |    utput="gp_ortho" memory=300 offset=0                                    |
 |                                                                            |
 +----------------------------------------------------------------------------+

Moritz Lennert believes that this is a memory issue limit with r.univar. He suggested I submit this bug report.

Kind regards

James