Greets:
Just a long shot question. I have a number of NOAA charts that I would like to
remove the collars from. Is there any combination of plugins and methods
available for qgis that would allow me to accomplish this task.
Best regards and thanks.
--
/ch
___
Chris h ha scritto:
> Just a long shot question. I have a number of NOAA charts that I would like
> to
> remove the collars from. Is there any combination of plugins and methods
> available for qgis that would allow me to accomplish this task.
sorry about my ignorance, but what is a map colla
Chris h ha scritto:
> No apology necessary. Map collars are the white borders around maps that are
> typically distributed from governmental sources in raster format. In order to
> stitch or glue charts together you need to remove the collars. (white area)
Oh, that can be easy: for displaying p
Although, this approach can be problematic if white is important for
properly displaying the map information. E.g., USGS topographic maps
use a white background for the map and a white collar. My solution was
to hand select the collar in Gimp, make it a unique color (magenta or
something),
I realize this goes into other software on a qgis list, but I wonder
with GDAL or GRASS one can accomplish this.
It is really a raster clip that would work well, especially if the
next step is mosaic'ing the rasters. Are these quad maps?
Mark
On Mar 18, 2009, at 3:28 PM, "John C. Tull"
On Wednesday 18 March 2009 16:07:18 MS wrote:
> I realize this goes into other software on a qgis list, but I wonder
> with GDAL or GRASS one can accomplish this.
>
> It is really a raster clip that would work well, especially if the
> next step is mosaic'ing the rasters. Are these quad ma
The ch
You could create a polygon in qgis (or some automated way), find an unused
pixel value in the chart, and then use gdal_rasterize -i to burn it into the
collar area. You can then use that as the transparency value.
On Wed, Mar 18, 2009 at 3:32 PM, Chris h wrote:
> On Wednesday 18 March 2009 16:0
...and would be so nice having a GUI in QGIS for gdal_rasterize and the
rest of
gdal utilities!
Agus
Jamie Adams wrote:
You could create a polygon in qgis (or some automated way), find an
unused pixel value in the chart, and then use gdal_rasterize -i to
burn it into the collar area. You can
