DDS to CR2 Converter

Encoding: the DDS uses block compression (BC1 to BC7, also called DXT) or uncompressed RGBA; CR2 uses lossless JPEG-compressed sensor data, cut into vertical slices, and the download is a Linear DNG: demosaiced 8-bit RGB with the colour matrices raw editors need.

Bit depth: 8 bits per channel for common texture formats in the DDS; CR2 allows 12 or 14 bits per channel, and the DNG written here has 8 bits per channel, linearised.

Colour: RGB(A); normal maps and packed masks store data rather than colour in the DDS; CR2 supports camera RGB from a Bayer mosaic, with the Picture Style recorded in the maker notes, written here as 8-bit sRGB.

Transparency: the DDS stores it as alpha inside the compressed blocks (BC2, BC3, BC7) or a 1-bit cut-out (BC1); the DNG has none, so transparent areas are filled with the colour you choose.

Other images: the DDS can hold mipmaps, cubemap faces or texture arrays; only the main image is converted.

Metadata: the DDS can carry a 128-byte header (plus a DX10 header) describing the pixel format, nothing about the picture; CR2 can carry EXIF, Canon maker notes (Picture Style, lens, focus points) and the embedded previews, but nothing is copied across.

DDS is a GPU texture format used by DirectX games. It stores block-compressed textures (DXT/BC) and mipmaps that graphics cards decode directly.

A DDS file starts with 'DDS ' and a 124-byte header giving the size, mipmap count and pixel format: a FourCC such as DXT1 or DXT5, or 'DX10' followed by an extra header naming a DXGI format. The largest mipmap comes first.

DDS files usually come from DirectX games, game mods and texture tools such as NVIDIA Texture Tools and Intel's texture plugin.

CR2 is the raw format of Canon EOS cameras from 2004 until CR3 replaced it in 2018. It holds the sensor's 12 or 14-bit readings, losslessly compressed, plus a large JPEG preview rendered with the camera's Picture Style.

CR2 is TIFF-based: the TIFF header is followed by the letters 'CR' and version 2.0, then four image directories: a large JPEG preview with the EXIF block, a 160×120 thumbnail, a small uncompressed RGB image, and the sensor data as lossless JPEG cut into vertical slices.

CR2 files come from Canon EOS DSLRs made from 2004 to 2018, such as the 5D Mark II and III, 6D, 7D and the Rebel series.

Forms and workflows that ask for CR2 usually feed a raw editor, and each of those opens DNG as well, so the DNG can take the CR2's place. Keep the DDS if you only need to view or share the picture.

What CR2 offers when it comes straight from the camera: Large embedded JPEG rendered with the camera's Picture Style; Lossless 12 or 14-bit sensor data; Widely supported after fourteen years of Canon DSLRs. Its drawbacks: Replaced by CR3 in 2018, so current Canon bodies no longer write it; 20 to 50 MB per photo; Sliced lossless JPEG data that only raw decoders can read.