While I was reading chapter 8, from Neteler & Mitasova GRASS Book, I realized that there is no specific sub-chapter related with Geometric Correction. This process is to compensate for the distortions introduced by these factors so that the corrected image will have the highest practical geometric integrity (Lillesand & Kiefer).
My question is: How can this be done in GRASS? I suppose it’s done since LANDSAT-TM need geometric correction and, all GRASS book refers to LANDSAT images.
I just need a couple of tips 
Thank you
Luis
On Wed, Feb 3, 2010 at 5:05 PM, Luis Lisboa <luislisboa1975@gmail.com> wrote:
While I was reading chapter 8, from Neteler & Mitasova GRASS Book, I
realized that there is no specific sub-chapter related with Geometric
Correction. This process is to compensate for the distortions introduced by
these factors so that the corrected image will have the highest practical
geometric integrity (Lillesand & Kiefer).
My question is: How can this be done in GRASS?
The Imagery TODO list is the following:
- merge of image libraries:
A)
- lib/imagery/: standard lib, in use (i.* except for i.points3, i.rectify3)
- imagery/i.ortho.photo/libes/: standard lib, in use
(i.ortho.photo, photo.*)
B)
- lib/image3/: never finished improvement which integrated the
standard lib and
the ortho lib. Seems to provide also ortho rectification for
satellite data (i.points3, i.rectify3)
- image modules:
- merge of i.points, i.vpoints, i.points3
- merge of i.rectify and i.rectify3
- addition of new resampling algorithms such as bilinear, cubic convolution
(take from r.proj?)
- add other warping methods (maybe thin splines from GDAL?)
- implement/finish linewise ortho-rectification of satellite data
- Add support for > 8bit colors (only 0-255 supported currently)
Relevant for you is this:
- "implement/finish linewise ortho-rectification of satellite data"
...unfortunately stuck since GRASS 4/5...
I suppose it's done since
LANDSAT-TM need geometric correction and, all GRASS book refers to LANDSAT
images.
(A part of the book refers to LANDSAT.)
It would be great to see the existing algorithms integrated.
Best
Markus
Relevant for you is this:
- “implement/finish linewise ortho-rectification of satellite data”
…unfortunately stuck since GRASS 4/5…
Regarding this… According to Lillesand and Kiefer the idea is to correct geometric distortions of the image.
For instance, the Georrectify module is not enough? or the i.rectify function?
It would be great to see the existing algorithms integrated.
Ok Since I will need to do some work on this, at the end I can contribute with some code/functions
Cheers
Luis
On Thu, Feb 4, 2010 at 2:06 PM, Luis Lisboa <luislisboa1975@gmail.com> wrote:
Relevant for you is this:
- "implement/finish linewise ortho-rectification of satellite data"
...unfortunately stuck since GRASS 4/5...
Regarding this... According to Lillesand and Kiefer the idea is to correct
geometric distortions of the image.
For instance, the Georrectify module is not enough? or the i.rectify
function?
It is not enough because it is made for aerial photos (central projection)
while satellite data are line-wise scanners (so central projection only
in one direction).
It would be great to see the existing algorithms integrated.
Ok Since I will need to do some work on this, at the end I can contribute
with some code/functions
great! happy hacking,
Markus
Ok I see
Are there any remains from the code that was stuck in GRASS 4/5?
On Thu, Feb 4, 2010 at 2:11 PM, Markus Neteler <neteler@osgeo.org> wrote:
On Thu, Feb 4, 2010 at 2:06 PM, Luis Lisboa <luislisboa1975@gmail.com> wrote:
Relevant for you is this:
- “implement/finish linewise ortho-rectification of satellite data”
…unfortunately stuck since GRASS 4/5…
Regarding this… According to Lillesand and Kiefer the idea is to correct
geometric distortions of the image.
For instance, the Georrectify module is not enough? or the i.rectify
function?
It is not enough because it is made for aerial photos (central projection)
while satellite data are line-wise scanners (so central projection only
in one direction).
It would be great to see the existing algorithms integrated.
Ok Since I will need to do some work on this, at the end I can contribute
with some code/functions
great! happy hacking,
Markus
On Mon, Feb 8, 2010 at 10:13 AM, Luis Lisboa <luislisboa1975@gmail.com> wrote:
Ok I see
Are there any remains from the code that was stuck in GRASS 4/5?
No, "just" the absence of a developer ... luckily image processing in GRASS
is gaining new interest.
Markus