Kumoy Now Supports Raster Data in Web Maps

Introduction

Kumoy is a service that lets you upload maps and data created in QGIS to the cloud and view and share them as web maps. Until now, Kumoy supported creating and sharing maps from vector data.

This update adds support for uploading raster data. You can share elevation data, satellite imagery, aerial photographs, and other raster data on the web just like vector data.

This article covers what raster support makes possible, the steps for sharing from QGIS as a web map, usage examples, and points to note.

What raster support lets you do

Until now, you could share maps made from vector data on the web with Kumoy. With this update, you can handle raster data in the same workflow as vector data.

To use Kumoy's raster features, you need QGIS 3.44 or later and Kumoy plugin v3.0.1 or later. Update the plugin from the plugin repository.

Upload directly from QGIS

In QGIS, select the raster layer you want to share and register it in the cloud with Kumoy's upload feature. You do not need to convert the file format beforehand or set up an environment for web delivery.

You can upload the many kinds of raster data that QGIS supports, such as elevation data, multiband satellite data, and raster analysis results from QGIS.

Combine with vector data in a web map

You can display uploaded raster data together with vector data such as basemaps, roads, buildings, and survey points. You can share a map made in QGIS, including its raster layers, as a web map.

Share with people who do not use QGIS

People who view the map do not need QGIS or the original data. They only open the web map in a browser to see the contents, so you can use it for internal reviews, explanations to clients, and viewing in the field.

Upload from QGIS to Kumoy

You share raster data with the same workflow as vector data.

1. Prepare the raster layer you want to share in QGIS.

2. Right-click the raster layer and select Convert to Kumoy Raster, or use the Processing tool Upload Raster Layer to Kumoy, to upload the raster data to Kumoy.

3. Create a web map that includes the raster layer and share it.

Do the analysis and styling in QGIS, and check the finished map in a browser. The GIS staff and the people who review the map do not need to prepare the same QGIS environment or the original data.

Examples of using raster data

With raster data support, you can share information that you used to pass around as images or files as a web map combined with other GIS data.

Share elevation data and terrain information

You can share elevation data such as a digital elevation model (DEM) or digital surface model (DSM) together with vector data such as roads and target areas. Showing the relief and the distribution of elevation in a web map makes it easier to convey terrain information to people outside the GIS team.

Share site conditions from satellite imagery and aerial photographs

You can share satellite imagery and aerial photographs overlaid with roads, buildings, farmland polygons, and more. You can also upload analysis results such as NDVI created from satellite imagery, so you can share the condition of farmland and forests with staff who do not use QGIS.

Compare georeferenced paper maps with current maps

You can georeference old maps, past plans, survey drawings, and similar materials in QGIS, then overlay them on current basemaps and vector data and share them. Because paper materials become maps with location information, this is useful for comparing the past with the present and for explaining to people who do not use QGIS.

Supported formats and points to note

Raster data uploaded to Kumoy is automatically converted to Cloud Optimized GeoTIFF (COG). COG is a GeoTIFF format designed so that even large raster data can load just the area you need efficiently. You do not need to convert to COG beforehand.

Examples of supported data

• Elevation data in GeoTIFF format
• Satellite imagery and aerial photographs
• RGB and RGBA raster data
• Raster data with multiple bands
• Analysis results created in QGIS

Points to note

• You can upload up to 4 GB per file.
• Common raster styles set in QGIS are supported.
• Some styles are not supported, such as blending and certain coloring methods.
• Kumoy keeps the coordinate reference system (CRS) of the original data. For data with no CRS, assign one in QGIS before you upload it.

Conclusion

With raster data support in Kumoy, you can now share elevation data, satellite imagery, aerial photographs, and analysis results created in QGIS as web maps, combined with vector data.

The person who makes the map prepares the data in QGIS as usual, and the people who review it view the map in a browser. If you want to share QGIS projects that include raster data, or use analysis results across your team, give Kumoy a try.

Data used

• GSI Tiles (Geospatial Information Authority of Japan)
• “Sapporo Shigai no Zu (Map of Sapporo City),” Hokkaido Government Office, June 1911. NDL Digital Collections
• “National Land Numerical Information (Railway Data)” (Ministry of Land, Infrastructure, Transport and Tourism)
• “National Land Numerical Information (Municipal Offices and Public Assembly Facilities Data)” (Ministry of Land, Infrastructure, Transport and Tourism)
• Sediment disaster warning areas (Regional Development Bureaus of the Ministry of Land, Infrastructure, Transport and Tourism and others, and prefectures)
• JAXA GCOM-C/SGLI sea surface temperature (SST) data