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 p.1 #5 · Photoshop/Mac save as TIFF | |
Uncompressed TIFF is a legacy format for programs that cannot read compressed TIFF. It's one of the easiest formats to read since there is no encoding/decoding scheme to implement. The result is a very large file, but being so simple, this file format is virtually guaranteed to be readable for all eternity. It's quite literally just the binary data for each pixel (so for example, an 8-bit RGBRGB TIFF, after the header information, would represent each pixel as a string of 24 bits, the first third being the red channel, second third being green, etc.).
LZW was the first compression type used for TIFF, and of the various compressed TIFF types, this is the one that is most commonly supported. It is a lossless encoding and gives fairly good encoding/decoding speed. As such, there is very little reason to use uncompressed TIFF--the output is identical and does not degrade with repeated decoding/encoding, unlike lossy JPEG.
ZIP is a relatively more recent compression scheme that (like LZW) was originally implemented for compressing general files, but achieves slightly better compression ratios. Reading ZIP-encoded TIFF is supported by Photoshop, but not as many other applications support it. If you do not require much compatibility, then consider using ZIP-TIFF, as it too is lossless.
I would not use JPEG-TIFF, since support for this encoding scheme is quite limited, and as such there is very little reason to use it over PSD or just normal JPEG.
In fact, PSD or PSB (large document format) are, for most purposes, the best option to use if working in Photoshop. Your documents are losslessly compressed, and although possibly slightly larger than an equivalent compressed TIFF, you also have the most compatibility for whatever layer and vector information may be contained in the image. Also, Photoshop reads PSD and PSB faster than TIFF. The only real reason to use TIFF is to provide support for other applications that cannot read PSD, but you want to retain lossless compression (or in some cases, support for legacy applications where uncompressed TIFF is expected).
Regarding channel interleaving, RGBRGB is the most commonly encountered ordering, so leave it at that. Some programs, like Photoshop, can auto-detect the ordering.
Other important notes about the TIFF format: The bit depth and color space* of the image at save time will also be preserved when the file is written, so if the file is in 16-bit RGB mode, it will be saved as a 16-bit RGB TIFF. If you are in L*a*b mode, it will save it as in that color space, and same for CMYK. Not all applications can read these types of TIFF, even if no compression is applied! Many applications will expect 8-bit RGB TIFF data, and can be confused otherwise. So if your intent is to use these files in another program, be sure that program has support for that format.
*Note that "color space" is not the same as "color profile." Color profile is the color management setting that is being used to relate consistent colors across various output devices, and does not affect the actual color data in the file. For applications that are profile-aware, they will translate the RGB data and attempt to display it in a way that is consistent with other devices (if calibration is correct for each device).
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