What is the MRW file format?
.mrw is the proprietary camera raw format produced by Minolta and Konica Minolta digital cameras from approximately 2002 through 2006. It stores unprocessed Bayer-pattern sensor data at 12 bits per channel, along with embedded metadata and a TIFF thumbnail.
The file begins with the four-byte signature \0MRM (hex 00 4D 52 4D) and uses big-endian byte order throughout. Internally, data is organized into tagged sub-blocks: PRD (picture raw data descriptor), WBG (white balance gains), RIF (requested image format and Exif), and TTW (a complete TIFF/Exif structure with thumbnail). The packed 12-bit Bayer pixel data follows these header blocks.
The format covered Minolta DiMAGE cameras (5, 7, 7i, 7Hi, A1, A2) and Konica Minolta DiMAGE models (A200, 5D, 7D), topping out at approximately 8 megapixels with the DiMAGE A2.
.mrw is a fully legacy format. Konica Minolta exited the camera business in 2006, and Sony - which acquired the Alpha camera line - adopted .arw for all subsequent models. All .mrw files originate from cameras produced between 2002 and 2006.
Despite its age, .mrw is well supported by raw processing tools including Adobe Camera Raw, Adobe DNG Converter, RawTherapee, and darktable.
Security & safety
RISK: LOWMRW is a passive camera raw image file containing sensor data and metadata - no executable code. Opening one is safe. EXIF metadata (camera, lens, sometimes GPS, timestamps) is embedded in the TTW block and travels with the file - strip with ExifTool before publishing if privacy matters. The format is stable and well-supported by LibRaw in modern tools.
Format details
in a nutshellPrograms that open MRW files
Windows11 apps
Adobe Photoshop Lightroom
Paid Import MRW into Lightroom catalog for non-destructive editing and batch export to JPG. 
darktable
Open-source Free, full-featured raw developer; import the MRW to edit non-destructively and export to JPG/TIFF. 
Adobe DNG Converter
Free Batch-convert MRW files to open DNG format for long-term archiving and broad compatibility. 
macOS3 apps
Apple Photos / Preview
Built-in macOS has built-in MRW support via Core Image RAW; double-click to preview in Preview. 
Linux3 apps
Technical details
deep spec| Magic bytes | 00 4D 52 4D (null-MRM) at offset 0 |
| Byte order | Big-endian (Motorola byte order) throughout all multi-byte fields |
| Sub-block structure | PRD (raw data descriptor), WBG (white balance gains), RIF (image format + Exif), TTW (complete TIFF/Exif thumbnail block) |
| Raw pixel encoding | 12-bit packed Bayer CFA; RGRG/GBGB alternating row pattern |
| Color depth | 12 bits per channel; 36-bit effective RGB after Bayer demosaic |
| Embedded thumbnail | Full TIFF/Exif structure including Exif metadata and thumbnail JPEG stored in TTW sub-block |
| Compression | Uncompressed (most models); some use Sony proprietary lossless packing for 12-bit data |
| Typical file size | 5 MB - 25 MB depending on sensor resolution |
| Maximum resolution | Approximately 8 megapixels (Konica Minolta DiMAGE A2, 2003) |
| Camera compatibility | Minolta DiMAGE 5, 7, 7i, 7Hi, A1, A2; Konica Minolta DiMAGE A200, 5D, 7D |
| MIME type | image/x-minolta-mrw |
| Checksum | None - no built-in integrity check |
| Released | ~2002 (Minolta DiMAGE 7 series) |
| Latest version | Last used in Konica Minolta cameras through ~2006; Sony transitioned to ARW |
| Specification | www.dalibor.cz |
MRW conversions
Community Q&A
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