TIFF to EXR Converter

Encoding: the TIFF uses none, LZW, PackBits, Deflate or JPEG, chosen per file; EXR uses none, RLE, ZIP, PIZ, PXR24, B44 or DWA, chosen per file, and the download is a ZIP-compressed OpenEXR with 16-bit half-float channels, the 8-bit sRGB values converted to linear light.

Bit depth: 1 to 16 bits per channel, or 32-bit floating point in the TIFF; EXR allows 16-bit half or 32-bit floating point per channel, and the EXR written here has 16-bit half float per channel. 16-bit and floating-point TIFFs are reduced to 8 bits per channel.

Colour: RGB, CMYK, Lab, greyscale or palette, often with an ICC profile in the TIFF; EXR supports scene-linear RGB, often ACEScg or linear Rec.709, written here as linear-light RGB.

Transparency: the TIFF stores it as an extra sample declared in the ExtraSamples tag; the EXR keeps it as an A channel stored like any other channel.

Other images: the TIFF can hold several pages, each in its own image file directory; only the main image is converted.

Metadata: the TIFF can carry EXIF, XMP, IPTC and ICC, all stored as tags; EXR can carry named header attributes such as chromaticities, timecode and camera data, but nothing is copied across.

TIFF is the professional archive and print format. It can hold multiple pages, high bit depths and lossless data, and is common in scanning, publishing and GIS.

A TIFF begins with 'II' or 'MM' for the byte order and the number 42, then an offset to the first image file directory (IFD): a table of tags giving the size, compression, colour model and the location of the strips or tiles of pixels. Each further page is another IFD.

TIFF files usually come from scanners, print and publishing workflows, photo archives and tethered camera capture.

OpenEXR is the high dynamic range format of film visual effects. It stores half or full floating-point channels in linear light, plus any extra render passes, and is the working format of compositing pipelines.

An EXR starts with the magic number 76 2F 31 01 and a version field, then a header of named, typed attributes (channels, compression, dataWindow, displayWindow) and a table of offsets to scanline or tile blocks.

EXR is the better choice for visual effects, compositing and 3D render output, while TIFF suits printing, scanning and archival masters.

EXR strengths: True high dynamic range in linear light; Any number of channels and render passes; Lossless compression options. Drawbacks to weigh: Needs tone mapping to look right on a normal screen; Very large files; No browser or phone support.