[GRASS-user] Processing NAIP images

GRASS GRASS user
,
1

Hi,

I am trying to generate land use maps (looking to identify roadways only, actually) using NAIP imagery.

Since I am using the pre-compiled GRASS, I do not have MrSID inside GRASS, so converted the images to TIFF using QGIS.

I believe I can use i.maxlik or something like that, but I do not know how to start. It keeps asking for groups, but I do not know what is a group image.

I googled a lot on this and looked into several tutorials, but still did not figure out how to start this. I have been educating myself through a few papers, but I guess I still need to find a good summarized tutorial on how to do this with multi band images such as NAIP.

Does anybody have ideas to help?

Thanks,

Pedro

2

Hi Pedro,

I did a test run and created an unsupervised classification image.

Here are the steps I did:

1 MrSID to tiff in QGIS
2 import tiff in GRASS (i.in.gdal)
3 create group and subgroup (i.group —check “Define also sub-group(same name as group)”— in the “Layers in selected group” keep one band file as described in i.cluster manual)
4 classification --signature(i.cluster)
5 classification–map (i.maxlik)

Hope it helps.

Best,
Jiao

···

On Tue, Jan 28, 2014 at 9:00 AM, Pedro Camargo <veigacamargo@gmail.com> wrote:

Hi,

I am trying to generate land use maps (looking to identify roadways only, actually) using NAIP imagery.

Since I am using the pre-compiled GRASS, I do not have MrSID inside GRASS, so converted the images to TIFF using QGIS.

I believe I can use i.maxlik or something like that, but I do not know how to start. It keeps asking for groups, but I do not know what is a group image.

I googled a lot on this and looked into several tutorials, but still did not figure out how to start this. I have been educating myself through a few papers, but I guess I still need to find a good summarized tutorial on how to do this with multi band images such as NAIP.

Does anybody have ideas to help?

Thanks,

Pedro

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3

Thanks, Jiao!! This helps a lot!!!

Pedro

From: Jiao Wang [mailto:jiao@hawaii.edu]
Sent: Tuesday, January 28, 2014 1:02 PM
To: Pedro Camargo
Cc: GRASS user list
Subject: Re: [GRASS-user] Processing NAIP images

Hi Pedro,

I did a test run and created an unsupervised classification image.

Here are the steps I did:

1 MrSID to tiff in QGIS

2 import tiff in GRASS (i.in.gdal)

3 create group and subgroup (i.group —check “Define also sub-group(same name as group)”— in the “Layers in selected group” keep one band file as described in i.cluster manual)

4 classification --signature(i.cluster)

5 classification–map (i.maxlik)

Hope it helps.

Best,

Jiao

On Tue, Jan 28, 2014 at 9:00 AM, Pedro Camargo <veigacamargo@gmail.com> wrote:

Hi,

I am trying to generate land use maps (looking to identify roadways only, actually) using NAIP imagery.

Since I am using the pre-compiled GRASS, I do not have MrSID inside GRASS, so converted the images to TIFF using QGIS.

I believe I can use i.maxlik or something like that, but I do not know how to start. It keeps asking for groups, but I do not know what is a group image.

I googled a lot on this and looked into several tutorials, but still did not figure out how to start this. I have been educating myself through a few papers, but I guess I still need to find a good summarized tutorial on how to do this with multi band images such as NAIP.

Does anybody have ideas to help?

Thanks,

Pedro

grass-user mailing list
grass-user@lists.osgeo.org
http://lists.osgeo.org/mailman/listinfo/grass-user

4

Hi,

I think you can find a lot of tutorial/cours on the grass website (under Documentation: http://grass.osgeo.org/documentation/tutorials/), on the wiki (http://grasswiki.osgeo.org/wiki/Image_processing) and also on the manual page (http://grass.osgeo.org/grass64/manuals/index.html). There are usually link to the man page for every command, with everything explained :wink:

for your job (identify roadways), I think you will mostly be interrested by:

Sylvain

···

2014-01-29 Pedro Camargo <veigacamargo@gmail.com>

Thanks, Jiao!! This helps a lot!!!

Pedro

From: Jiao Wang [mailto:jiao@hawaii.edu]
Sent: Tuesday, January 28, 2014 1:02 PM
To: Pedro Camargo
Cc: GRASS user list
Subject: Re: [GRASS-user] Processing NAIP images

Hi Pedro,

I did a test run and created an unsupervised classification image.

Here are the steps I did:

1 MrSID to tiff in QGIS

2 import tiff in GRASS (i.in.gdal)

3 create group and subgroup (i.group —check “Define also sub-group(same name as group)”— in the “Layers in selected group” keep one band file as described in i.cluster manual)

4 classification --signature(i.cluster)

5 classification–map (i.maxlik)

Hope it helps.

Best,

Jiao

On Tue, Jan 28, 2014 at 9:00 AM, Pedro Camargo <veigacamargo@gmail.com> wrote:

Hi,

I am trying to generate land use maps (looking to identify roadways only, actually) using NAIP imagery.

Since I am using the pre-compiled GRASS, I do not have MrSID inside GRASS, so converted the images to TIFF using QGIS.

I believe I can use i.maxlik or something like that, but I do not know how to start. It keeps asking for groups, but I do not know what is a group image.

I googled a lot on this and looked into several tutorials, but still did not figure out how to start this. I have been educating myself through a few papers, but I guess I still need to find a good summarized tutorial on how to do this with multi band images such as NAIP.

Does anybody have ideas to help?

Thanks,

Pedro

grass-user mailing list
grass-user@lists.osgeo.org
http://lists.osgeo.org/mailman/listinfo/grass-user

grass-user mailing list
grass-user@lists.osgeo.org
http://lists.osgeo.org/mailman/listinfo/grass-user