PNG to CR2 Converter

Encoding: the PNG uses lossless DEFLATE with a prediction filter chosen per row; 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: 1, 2, 4, 8 or 16 bits per channel in the PNG; CR2 allows 12 or 14 bits per channel, and the DNG written here has 8 bits per channel, linearised. 16-bit PNGs from photo and scientific software are reduced to 8 bits per channel.

Colour: RGB, greyscale, or an indexed palette of up to 256 colours in the PNG; 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 PNG stores it as a full alpha channel, so edges and shadows can fade smoothly; the DNG has none, so transparent areas are filled with the colour you choose.

Metadata: the PNG can carry text chunks, an ICC profile, physical resolution and EXIF in an eXIf chunk; CR2 can carry EXIF, Canon maker notes (Picture Style, lens, focus points) and the embedded previews, but nothing is copied across.

PNG stores pixels losslessly with full alpha transparency. It is ideal for screenshots, logos, UI and anything with sharp edges, but photos saved as PNG are several times larger than JPEG.

A PNG opens with an 8-byte signature and is a chain of chunks, each with its own CRC: IHDR (size, depth, colour type), optional PLTE and tRNS for palettes, one or more IDAT chunks with the compressed rows, and IEND.

PNG files usually come from screenshots, design exports, logos and web graphics.

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 PNG 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.