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Image Conversion

Convert DIB to BMP — Free Online Converter

Convert Device Independent Bitmap (.dib) to Bitmap Image (.bmp) online for free. Fast, secure image conversion with no watermarks or registration....

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How to Convert

1

Upload your .dib file by dragging it into the upload area or clicking to browse.

2

Choose your output settings. The default settings work great for most files.

3

Click Convert and download your .bmp file when it's ready.

About DIB to BMP Conversion

DIB (Device Independent Bitmap) is Microsoft's raw bitmap format — essentially a BMP without the 14-byte BITMAPFILEHEADER. DIB represents the in-memory bitmap structure used internally by Windows GDI (Graphics Device Interface) for device-independent rendering. The format stores uncompressed pixel data with a BITMAPINFOHEADER describing dimensions, color depth, and an optional color table. BMP (Bitmap Image) is the complete file format that wraps this same DIB data with a file header, making it a standalone disk file.

Converting DIB to BMP is a minimal structural operation — adding the 14-byte BITMAPFILEHEADER to the existing DIB data. This header contains the file type signature ("BM"), total file size, reserved fields, and the offset to pixel data. The pixel data itself is identical between DIB and BMP. This conversion is necessary when legacy Windows applications, clipboard operations, or embedded systems produce DIB files that modern software expects to receive as standard BMP.

Why Convert DIB to BMP?

Most modern image editors, viewers, and processing tools expect the standard BMP file format with its file header. While DIB and BMP contain identical pixel data, the missing file header in DIB causes many applications to reject the file or misidentify it. Converting to BMP adds the expected header, making the file universally recognizable by every Windows application, macOS Preview, Linux image viewers, and web browsers.

Legacy enterprise applications, industrial control systems, and embedded devices frequently produce DIB output from clipboard operations or direct GDI captures. These DIB files need to be converted to BMP before they can enter standard imaging workflows, be emailed as attachments, or be uploaded to document management systems that validate file headers.

Common Use Cases

  • Add the standard BMP file header to DIB files produced by legacy Windows GDI applications
  • Convert clipboard-captured DIB bitmaps to standard BMP for saving and sharing
  • Make DIB files from industrial control systems compatible with modern image viewers
  • Prepare DIB output from embedded systems for standard bitmap processing pipelines
  • Fix DIB files that modern software rejects due to the missing BITMAPFILEHEADER

How It Works

The conversion reads the DIB data starting from the BITMAPINFOHEADER, extracts the image dimensions, color depth, and color table information, then prepends a BITMAPFILEHEADER. The file header is constructed with: signature bytes 0x42 0x4D ("BM"), total file size (header + DIB data), two reserved 16-bit fields set to zero, and the pixel data offset (14 + BITMAPINFOHEADER size + color table size). The pixel data is copied verbatim — no resampling, color conversion, or compression is applied. The resulting BMP file is byte-identical to the original DIB data plus 14 bytes of header.

Quality & Performance

The conversion is completely lossless. DIB and BMP store identical pixel data — the only difference is the 14-byte file header that BMP includes. Every pixel, color value, and scanline is preserved exactly. The BMP output is mathematically identical to the DIB input in every way that affects image content.

SHARP EngineFastLossless

Device Compatibility

DeviceDIBBMP
Windows PCPartialNative
macOSPartialPartial
iPhone/iPadPartialPartial
AndroidPartialPartial
LinuxPartialPartial
Web BrowserNoNo

Tips for Best Results

  • 1This conversion is essentially just adding a file header — it is the lightest possible format conversion
  • 2If your application produces DIB files regularly, consider modifying it to output BMP directly
  • 3BMP files from this conversion are uncompressed and can be very large — consider further conversion to PNG or JPEG for storage efficiency
  • 4DIB files from clipboard operations may have unusual color depths — the conversion preserves whatever color depth the source uses
  • 5Test the output BMP in your target application immediately to confirm compatibility

DIB to BMP is the simplest possible image conversion — adding a 14-byte file header to make raw Windows bitmap data into a standard file. The operation is instantaneous, completely lossless, and produces universally compatible BMP output.

Frequently Asked Questions

BMP has a 14-byte BITMAPFILEHEADER at the start of the file that DIB lacks. The pixel data, color table, and BITMAPINFOHEADER are identical. DIB is the in-memory format; BMP is the file format.
Windows GDI internally works with DIB structures for device-independent rendering. When applications capture from the clipboard or export GDI surfaces, they sometimes write the raw DIB structure without adding the file header.
No. The conversion adds a file header only — no pixel data is modified, compressed, or altered in any way. The output is pixel-identical to the input.
No. Simply renaming the file does not add the missing file header. Applications that validate the BMP file structure will still reject the file because the header bytes are absent.
Yes. The operation consists of reading the DIB data and prepending 14 bytes. Processing time is negligible even for very large images.

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