Image Export Formats

[Midgardsormr]

TIFF is a raster "wrapper." Strictly speaking, it isn't a format, but a container that can hold several different formats of data. It is protected by a copyright currently owned by Adobe Systems, and it has never been fully standardized. As a result, some programs handle it differently than others, and there are occasions when a tiff written on one computer or by one application cannot be read by another. I have personally run into problems moving tiffs from PC to Mac installations of Photoshop, and also from my compositing software (Nuke) to Adobe Premiere on the same computer.

Advantages of TIFF include its ability to hold layer information, much like a Photoshop document, and multiple alpha channels. Many applications will misinterpret the additional channels, though, and there is really no way to know which channel will be selected as transparency, so it is advisable to include only a single alpha in a tiff intended for display. Some extensions to the Tiff format include support for high bit-depth images, up to 32 bits per channel (96 or even 128 bits per pixel), CMYK color, or even YCbCr (YUV) color.

Available compression algorithms that can typically be applied to a tiff include LZW, DEFLATE, and RLE. None of these do particularly well with photographic data; no better than PNG, really. As a result, there is not really any reason to choose tiff as a final export format over PNG. Tiff's flexibility is useful, but ultimately limits it as a format for interchange between artists and systems.