Convert ARW to BMP — Free Online Converter

ARW files from Sony Alpha cameras store 12-14 bit uncompressed Bayer pattern sensor data captured by models like the A7 III, A7R V, and A6000 series. Converting these RAW files to BMP produces an uncompressed raster image that preserves every pixel of the demosaiced output without any compression artifacts. BMP is one of the oldest image formats still in active use, offering a dead-simple structure that virtually every application on Windows can open instantly.

This conversion is useful when you need a completely uncompressed output from your Sony RAW files for scientific analysis, print proofing, or legacy software that cannot read modern compressed formats. The demosaicing process interprets Sony's Bayer filter array and reconstructs full RGB color for each pixel, then writes the result as a 24-bit or 32-bit BMP. Because BMP applies no compression whatsoever, the output is a faithful pixel-level representation of the processed RAW data.

BMP files are natively supported by every version of Windows going back to Windows 3.0, making them the safest choice when you need guaranteed compatibility with legacy desktop applications, embedded industrial systems, or scientific instruments. Many machine vision systems, medical imaging viewers, and industrial quality control software require uncompressed BMP input because they cannot decode JPEG, PNG, or other compressed formats.

Sony ARW files are not directly viewable without RAW-capable software like Lightroom, Capture One, or Sony's Imaging Edge. Converting to BMP gives you an immediately viewable, uncompressed image that any basic image viewer can display. This is particularly relevant in forensic photography and scientific documentation where the audit trail requires an uncompressed output format that has not been through lossy compression.

The conversion pipeline first decodes the Sony ARW file by reading its TIFF-based container structure, interpreting the 12-14 bit Bayer pattern data from the sensor, and performing demosaicing to produce full RGB pixels. White balance, gamma correction, and color matrix transforms from the camera metadata are applied. The resulting image is then written as a Windows BMP file at 24 bits per pixel (8 bits per channel). For a 42-megapixel A7R III file, the output BMP is approximately 120 MB uncompressed.