During one of our webinars last week covering the new features in MapInfo Pro v2021, a question was raised regarding raster projection.
The question was: "Have you corrected the projection issues when using Bing maps together with raster files in this version? This sometimes caused a shift in earlier versions."
I wanted to give a more detailed answer to this question as I don't think it actually is a bug.
First things first. Typically MapInfo Pro only reprojects vector data in map windows. If you add a raster dataset to a map window, MapInfo Pro will leave this data set position horizontally and instead project the vector layer to the raster layer. This is done because reprojecting vector layers typically is faster than reprojecting raster data.
If you have two or more raster layers in your map window, MapInfo Pro will let the biggest control the orientation of the map, and position the smaller data(s) closely to where it should be.
You can however see some shifts in this if the orientation of the image is different from the orientation of the bigger raster dataset. Again, this is because MapInfo Pro draws the raster images using their orientation.
I think this is causing the shift that was referred to in the question above.
You can, however, control how MapInfo Pro renders these raster datasets on the map, and force MapInfo Pro to align the raster datasets to the coordinate system of the map instead of aligning the coordinate system of the map to the rasters.
This can be set for the individual map window, and you can use a preference to control how a new map window will behave.
You can access this setting for an existing map via the Image Processing button in the Map Options dialog. The Map Options dialog can be accessed from the Map context menu or from the Options group on the Map tab.
The preference can be found via the Pro tab, access the Options tab on the Backstage, and open the Image Processing preference.
If you want MapInfo Pro to reproject raster to the current coordinate system of your map window, set the Reprojection option to Optimized or Always. We recommend Optimized.
This setting should also be changed from Never if you want to be able to show Tile Server layer, such as WMTS and TMS layer, in a different coordinate system than the service provided them in. This is a new feature in MapInfo Pro v2021.
Let's take a look at how you can change the coordinate system of a map with, or without, raster datasets.
In MapInfo Pro v2021, we made this a lot easier. From the statusbar, you can now click on the name of the current coordinate system.
This should open up the Choose Projection dialog. You may however sometimes get this error instead
If you get this error you will have to enable raster projection for the current map window using the process mentioned above.
If raster projection has been enabled for your map window, you will see the Choose Projection dialog where you can select the coordinate system, or projection, for your map window.
After selecting your desired projection, you click OK and MapInfo Pro will change the coordinate system of the map to the one you chose. You may see a small shift in the position of smaller raster datasets.
The new coordinate system name is reflected in the statusbar.
I hope this answers the question about the shift of raster images. If you still experience this shift, do reach out.