These instructions are based on MapInfo Professional 2019 and assume you have set the default coordinate reference system to British National Grid (EPSG 27700).
While MapInfo Professional can open GML files without prior translation, for performance and compatibility reasons, we recommended you use the Universal Translator built into MapInfo Professional versions 12.5 onwards to convert the GML supply to MapInfo TAB files prior to loading the data.
The sections below provide instructions for both working with GML data and converting to MapInfo TAB.
To load and display the GML supply directly in MapInfo Professional:
Open an existing workspace or create a new one.
From the Home tab, click Open > Universal Data.
In the Specify Data Source dialog:
Format: Select GML (Geography Markup Language).
Dataset: Click …, and navigate to and select the GML file (.gz) in the file browser.
Click OK.
In the Select Layers dialog, select the layers you want to load and click OK.
Your GML data will now display in the Maps panel and map area.
The data is un-styled. See documentsOS MasterMap Topography Layer Downloads for guidance on styling OSMM Topography Layer data.
To convert the GML supply to MapInfo TAB in MapInfo Professional:
Open an existing workspace or create a new one.
In the Home tab, click Open > Universal Data.
In FME Quick Translator, click Translate.
In the Set Translation Parameter dialog:
Reader Format: Select GML (Geography Markup Language).
Reader Dataset: Click …, and navigate to and select the GML file in the file browser.
Format: Select MapInfo TAB (MAPINFO).
Dataset: Click …, and navigate to and select the folder you want the translated data saved to.
Click OK.
You can watch the translation progress log in the FME Quick Translator. It will take some time; a single 5km tile of OSMM Topography Layer in GML format takes approximately 30 seconds. When the process is complete, a message similar to the example below will display.
You can now close the FME Quick Translator.
You can now load the translated data into MapInfo Professional as TAB format using the instructions provided in the following section.
If translating multiple tiles of OSMM Topography Layer using the above method, the files will be automatically appended into a single table, avoiding the need to merge tables. However, duplicate features are not removed automatically. See Deleting duplicate entries from tables for guidance on how to handle this.
To load the converted MapInfo TAB files in MapInfo Professional:
Open an existing workspace or create a new one.
From the Home tab click Open > Table.
In the file browser:
Files of type: Select MapInfo (*.tab).
Navigate to the folder in which you stored the converted MapInfo TAB files and select the layers you want to open.
Click Open.
Your MapInfo TAB data (.tab) will now display in the Maps panel and map window.
The data is un-styled. See documentsOS MasterMap Topography Layer Downloads for guidance on styling OSMM Topography Layer data.
In MapInfo Professional it is possible to merge the elements of two TAB files into one new table using the append function.
Appending only works for data tables of the same type AND for two TAB files at a time. Because OS MasterMap Topography Layer data comprises six individual tables, we recommended that you merge two or more tiles during the conversion from GML to TAB process.
To merge two TAB tables:
Follow the steps in Converting GML to MapInfo TAB above for both files.
Select one of your tables in the Explorer panel.
In the Home tab click Append Rows.
In the Append Rows to Table dialog:
Append Table: Select the table that will be appended.
to Table: Select the table to append to
Click OK.
The data from one table will now have been appended into the other. You will need to save the table to retain the appended data. See below for instructions on how to do this.
To verify which table contains the appended data:
Right-click a table in the explorer and click Browse Table in the context menu.
The total number of rows in the table displays in the bottom bar; this value of will be considerably larger for the table that included the appended rows.
To save the table:
Select the table containing the appended rows in the explorer.
From the Table tab click Save > Save Table.
As an alternative, you can use the Save Copy As action to additionally retain the original, unmerged table.
In the Save Table confirmation dialog click Save to confirm your action.
Your table will now contain the data for both original TAB files; you can verify this by opening the table to check the contents.
While the files are now merged, duplicate features (resulting from “hairy tiles”) are not removed automatically. See Deleting duplicate entries from tables for guidance on how to handle this.
There are several ways to delete duplicate entries from tables MapInfo Professional. Please refer to the MapInfo Professional documentation for guidance:
How to find All Records With Duplicate Values in a Column in MapInfo Pro (precisely.com). This article describes how to use SQL queries.
User Guide: Search for the Delete Duplicates Tool.
