These steps show how to calibrate scanned maps.
In this example we work with Polish projection - Borowa Gora
1. Import raster (format *.jpeg, *.jpg)
2. Create control points on raster. Add them clock wise.
3. Create empty drawingand assign projection (Polish - Borowa Gora). Manifold definition in XML file can be downloaded from here, and here is how to use it: http://cartoninjas.net/post/2010/08/27/Defitions-of-Polish-projections-for-manifold.aspx Downloaded file copy to your "Config" directory under Manifold installation directory. Restart Manifold.
New coordinates definition will be available under "National Grids" -> "Polish custom"
4. Add Graticule to our drawing.
Longitude and Latitude values should be read from map... remember to conver minutes and seconds to decimal format for e.g. if upper left corner on the map shows 53°30' this will be 53.5 in decimal notation which is required in Manifold.
Un-tick "Same spacing" and set different values for Longitude and Latitude.
From dropdown list in "Style" select "Tiles" and press "Create" button to create taile. Use CTRL+0 keys combination to "Zoom to fit". This should fit to our tile.
Switch on "Snap to Graticule" - so we create our control points exactly in tile cornes
Create four "Control points" clock wise
4. Open calibration dialog box from "raster control points" - press register button in Control Points dialog box, and select "Drawing" as reference object.
Press OK to start registering raster.
5. Having selected our drawing, create new "Map" component drag&drop our registerd raster and drawing. Change display styles for drawing component.
Now our map should look like here.
6. Raster is now calibrated and geo-referenced. Check and apply if "Borowa Gora" projection if it isn't set yet.
- Go to image in "Project pane"
- Select image
- Right click and select "Assign projection" - set "Borowa Gora"
7. Now we want to transform our image to WGS84 (Lat, Lon).
Select raster in "Project Pane" and select "Change Projection" and select WGS84
Manifold might ask you to confirm raster projection change.
Raster in new projection below.
Having selected raster in "Project Pane" create new "Map" component. At this stage add only raster to our new map.
Drag and drop "Drawing" with control points to new map. You'll see that Manifold has reprojected tile on the fly - this hasn't change drawing projection itself.
Select tile in drawing component - we will use selected rectangle to clip our raster.
8. It’s time to use powerful Manifold feature called “Transfer selection”.
Select raster layer on the map, and from “Image” menu select “Transfer Selection…” option
This tells to Manifold to transform "Modify" raster using our "Drawing"
9. CTRL+C – copy selected pixels and paste them as new image in “Project Pane”.
Manifold remembers component name from which new image was created, so now in "Project Pane" we have new image component with "_2" in its name.
Export it to "*.ecw" file format with default compression options.
Here is our final product:
All those steps except capturing control points can be scripted down and automated. As we did for this project