Convert BPW to BIL

Understanding BPW and BIL file formats

BPW files are World Files used in GIS (Geographic Information Systems) to provide georeferencing information for raster images, such as those in BMP format. The BPW file contains coordinates and transformation data that align the image with real-world locations.

BIL stands for Band Interleaved by Line, a raster file format commonly used for storing satellite imagery and remote sensing data. BIL files store pixel values in a way that is efficient for multi-band images, making them popular in GIS and remote sensing applications.

How to convert BPW to BIL

Since BPW files only contain georeferencing data and not the actual image, converting BPW to BIL typically involves pairing the BPW file with its associated raster image (such as a BMP file) and exporting the combined data to the BIL format. This process is usually performed in GIS software that supports both formats.

Recommended software for BPW to BIL conversion

• GDAL (Geospatial Data Abstraction Library): A powerful open-source library and command-line tool for raster and vector data conversion. Use the gdal_translate command to convert BMP+BPW to BIL.
• QGIS: A free and open-source GIS application. Open your BMP image (with the BPW file in the same directory), then use Raster → Conversion → Translate (Convert format) to export as BIL.
• ArcGIS: A professional GIS suite. Add your BMP and BPW files, then use Data → Export Data and select BIL as the output format.

Step-by-step conversion using QGIS

1. Place your BMP and BPW files in the same folder with matching filenames.
2. Open QGIS and use Layer → Add Layer → Add Raster Layer to load the BMP image.
3. QGIS will automatically read the BPW georeferencing data.
4. Go to Raster → Conversion → Translate (Convert format).
5. Select the loaded raster as input and choose BIL as the output format.
6. Click Run to create your BIL file.

Tips for successful conversion

• Ensure the BPW file matches the raster image filename (e.g., image.bmp and image.bpw).
• Check the output BIL file in your GIS software to confirm georeferencing is preserved.
• Use GDAL for batch conversions or automation.