Oziexplorer map format windows#
When you move your curser in the map windows you can check the XY and LatLon coordinates in the WGS84 and NDG datum.Ĭhoose a name for the resampled output fileĬhoose the target georeference: New, this is a Georeference Corner In the Pixel Information window select: File>Add Coordinate system> LatLon and LatLonWGS84. In the Map window you can check the georeference by selecting File>Open Pixel Information. You can remove the grid lines with Remove layer in the map window.Īdd/change tiepoints and/or change the transformation method with the Georeference Editor as the results are not good enough. Stop the editor and select in the map window: Layers>Add Grid Lines To check the results you can display grid lines and see how they match with the grid lines of the map.
Oziexplorer map format full#
It depends on the distortions in the map how many points you need, I took many.Ĭhoose a non-linear transformation method, like Full Second Order, look to the Sigma value (standard deviation), the lower the value the better the results. In the dialog box you see the local pixel coordinates, you have to type in the XY values from the map. With the opened Georeference Editor you can digitize the grid points with your mouse. Step 4 Digitize the grid points (Tie points) I used the 1SP parameters with the scale factor, if the 2SP parameters are used the scale factor is 1.ĭatum: User defined, dx= 1383, dy=44, dz=454 Select the radiobutton CoordSystem Projection Give a description (I choose: Coordinate system for the M831 map serie). Select the radio button Georeference Tiepoints.Ĭoordinate system> push the button to create one.Ĭhoose a Coordinate system name (I choose Nord de Guerre). In the Map Window select File>Create Georeference.Ĭhoose a Georeference name (I choose the same name as the raster map).
In this step we define the controlpoints and the non-linear transformation to resample the image. Step 3 Create a Georeference for the raster mapĪ Georeference is the same as a callibration in OziExplorer. In the main window of Ilwis select Open>Import>Ilwis>Raster>Tif.Īnd click OK and a Ilwis raster map is produced. If necessary convert your input file to Tif format (it can be done with IrfanView). Step 1 Get your image in the right file format When you are ready to correct your scanned images take the follwing steps:
Oziexplorer map format software#
ILWIS comprises a complete package of image processing, spatial analysis and digital mapping.īecause it has rich functionality you need some time to learn using it, but there is a very good user guide with extensive tutorials and it has a full on-line help.ĭownload the software and the tutorials and do some exercises to introduce yourself to ILWIS. Ilwis (Integrated Land and Water Information System) is open source GIS & Remote Sensing software, developed by ITC up to release 3.3 in 2005. In this blog I write about my experiences how this can be done with Ilwis. On the Internet you can find several image processing software products for correcting distortions. The resample software can calculate the correct new pixel coordinates of the grid points and transform the closed-by pixels according to them in the new image. These distortions are not linear in the map, in some parts the difference is for example +1 mm, in some other -5 mm or so.Ī georeference definies the transformation between the pixel row/colum coordinate in the image and the X/Y map coordinate in the real world.Ībout the grid points in the map we know both coordinates, when we are able to define the relation between them better, with a non-linear transformation, it is possible to resample the image to get a map that can be used better in OziExplorer, representing correct lat/lon positions of any pixel of the image. If you calibrate (georeference) the map in OziExplorer and display the lat/lon grid, you will see that the grid of the image does not match with the grid displayed by OziExplorer. When you view the scanned image, sometimes you can see that lines that should be straight, are not. There are several causes for distortions such as scanner mechanical, paper deformation and humidity. In a previous blog I wrote about some challenges using historical maps in OziExplorer.Īnother challenge can be image distortions by scanning old paper maps.