[GRASS-dev] v.lidar category numbers

GRASS GRASS developer
1

Hi,

I'm a bit confused with v.lidar EDGE/TERRAIN/UNKNOWN #defines.

v.lidar.edgedetection categorizes data points as either of those three.

output vector map includes cats 0,1,2 by layer 1.
(also there is a DB on layer 3, but that is not important to this email)

man page says:
EDGE (cat = 1, layer = 1)
TERRAIN (cat = 2, layer = 1)
(so cat=0 is UNKNOWN ??)

vector/lidar/v.lidar.edgedetection/edgedetection.c has:
    /* 0 = PRE_TERRAIN */
    /* 1 = PRE_EDGE */
    /* 2 = UNKNOWN */

vector/lidar/lidarlib/PolimiFunct.h has:
    /* PRE-CLASSIFICATION */
#define PRE_TERRAIN 1
#define PRE_EDGE 2
#define PRE_UNKNOWN 3

In v.lidar.growing I don't see any of these clearly but I guess they
must be there.

... I am a little confused. I'd like to update the v.lidar.edgedetection
man page to say what cat 0 in its output means.

thanks,
Hamish

2

On Fri, Jun 19, 2009 at 1:27 PM, Hamish<hamish_b@yahoo.com> wrote:

Hi,

I'm a bit confused with v.lidar EDGE/TERRAIN/UNKNOWN #defines.

v.lidar.edgedetection categorizes data points as either of those three.

output vector map includes cats 0,1,2 by layer 1.
(also there is a DB on layer 3, but that is not important to this email)

man page says:
EDGE (cat = 1, layer = 1)
TERRAIN (cat = 2, layer = 1)
(so cat=0 is UNKNOWN ??)

vector/lidar/v.lidar.edgedetection/edgedetection.c has:
/* 0 = PRE_TERRAIN */
/* 1 = PRE_EDGE */
/* 2 = UNKNOWN */

vector/lidar/lidarlib/PolimiFunct.h has:
/* PRE-CLASSIFICATION */
#define PRE_TERRAIN 1
#define PRE_EDGE 2
#define PRE_UNKNOWN 3

In v.lidar.growing I don't see any of these clearly but I guess they
must be there.

... I am a little confused. I'd like to update the v.lidar.edgedetection
man page to say what cat 0 in its output means.

Via Maria Brovelli/Sara Lucca I obtained this answer

----- start cite -----
The output of v.lidar.edgetection is:
TERRAIN (cat = 1, layer = 1)
EDGE (cat = 2, layer = 1)
UNKNOWN (cat = 3, layer = 1)

Nothing correspond to category 0.

So the correct classification is the one in the PolimiFunct.h

    vector/lidar/lidarlib/
    PolimiFunct.h has:
       /* PRE-CLASSIFICATION */
    #define PRE_TERRAIN 1
    #define PRE_EDGE 2
    #define PRE_UNKNOWN 3

In the man page there is an error, in fact the category referring to
terrain and edge are switched:

    man page says:
     EDGE (cat = 1, layer = 1)
     TERRAIN (cat = 2, layer = 1)
    (so cat=0 is UNKNOWN ??)

The comment in the file edgedetection.c is wrong, probably it is
something left from an old version of the code:

    vector/lidar/v.lidar.

    edgedetection/edgedetection.c has:
       /* 0 = PRE_TERRAIN */
       /* 1 = PRE_EDGE */
       /* 2 = UNKNOWN */

----- end cite -----

Markus

3

On Sun, Jul 19, 2009 at 9:22 PM, Markus Neteler<neteler@osgeo.org> wrote:

On Fri, Jun 19, 2009 at 1:27 PM, Hamish<hamish_b@yahoo.com> wrote:

Hi,

I'm a bit confused with v.lidar EDGE/TERRAIN/UNKNOWN #defines.

Fixed in SVN (6.4, 6.5, 7).

Markus