Re: [Qgis-user] S57 creation/export
On dimanche 24 mai 2020 20:23:16 CEST Jonathan Moules wrote: > Hi Matt, > > I may be wrong, but I don't believe so. GDAL (which sits behind much of > the format abilities of QGIS) is read-only for S-57: > > https://gdal.org/drivers/vector/s57.html Not completely true, if you go to the bottom of the doc: https://gdal.org/drivers/vector/s57.html#s-57-export Basically you need to provide input layers with the same structure as the ones of the read- side of the driver Some tests of S57 to S57 translation at: https://github.com/OSGeo/gdal/blob/master/autotest/ogr/ogr_s57.py#L205 Even -- Spatialys - Geospatial professional services http://www.spatialys.com ___ Qgis-user mailing list Qgis-user@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
Re: [Qgis-user] S57 creation/export
Hi Matt, I may be wrong, but I don't believe so. GDAL (which sits behind much of the format abilities of QGIS) is read-only for S-57: https://gdal.org/drivers/vector/s57.html Maybe someone has some suggestions how to accomplish it otherwise. Cheers, Jonathan On 2020-05-19 13:21, matt wrote: Hi there Is it possible to export a S-57 file from qgis? Thanks for your help Matt Sent from my iPhone ___ Qgis-user mailing list Qgis-user@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user ___ Qgis-user mailing list Qgis-user@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
Re: [Qgis-user] Raster
Hi William, I looked at the data you sent me. The problem is likely overexposed and that basically means very white value have band 1 to 3 set at 255,255,255. I tried three solutions. The first is to make all the white pixels null pixel. Then adding a Google Satellite layer under. The nodata pixels are transparent. That solution does not work basically because of pixel misregistration between both layers. It looks bad. See 2layer_solution in the project I sent you. The second option is to interpolate the nodata values (the white) using t.fill.stats found in the Processing toolbox, and then recombining the bands (look at the Interpolated_band123 layer) That could work but generally, pixel tend to become much darker. This should not be the case because we are dealing with highlights. Also, you have some highlights that are not 255,255,255 but very close. They now stick out. Maybe a better interpolation can be found. I did not play with this much. The best solution is the simplest. Use the green local stretch icon in the raster toolbar (you may need to activate it). Under layer > layer properties > Symbology set render type to multiband color. Red: min = 32, max =207, Green: min = 26, max = 179, and Blue: Min = 33, max 152 give good results. But basically zoom in and click the icon. This way, you will not notice the overexposure and the colors will be nicer. Cheers! Nicolas On 2020-05-24 12:01 a.m., William Reynolds wrote: I have a raster image I would like to assign a value to the 3 RGB bands that are equal to 255. I have several hundred raster images where the image is overexposed (white) and band1=255, band2=255 and band3=255. Is there a way to run a script that would assign a new value to each of the three bands if the band1, band2 and band3 values = 255? Bill ___ Qgis-user mailing list Qgis-user@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user ___ Qgis-user mailing list Qgis-user@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
Re: [Qgis-user] wishing for accurate lattitude/longitude from a cell phone
For years we did surveys with a customized solution with a Starfire GPS ( https://en.m.wikipedia.org/wiki/StarFire_(navigation_system)). It needs a subscription for best accuracy (see https://www.navcomtech.com/en/product/globalcorrectionservice/). It was linked to a trimble handheld data collector like this https://geospatial.trimble.com/products-and-solutions/geo-7x that have another integrated GPS. Pathfinder office is a great piece of software. I have to say that it was a bit difficult to handle all of this and needs a lot of checking and correction to have something reliable. I think it should be possible to use a smartphone. I did some tests with Mobile topographer which is pretty good and can be connected to an external gps using Bluetooth/serial/usb converters and some Android dedicated apps (like Bluetooth gps provider). But results needs to be checked, and it takes time. The accuracy is not all. A GPS has to be fast ! Professional GPS really are faster. I have to say that if I had to make large surveys again, I'd prefer to rent a professional solution. Maybe it's not cheaper but quality and saved time is worth the price. Jésahel ___ Qgis-user mailing list Qgis-user@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
