What third party dependencies do I need for the full functionality of libtiff when using it via Qt, OIIO or OpenCV?

Question

The libtiff library has the following external dependencies:

• zlib
• lzma
• zstd
• lerc
• jbig
• jpeg
• webp

As far as I know zlib, lzma, zstd, lerc and jbig are compression methods, while jpeg and webp are raster graphics file formats.

I use libtiff only indirectly via libraries like Qt, OIIO or OpenCV. I want to be able to read all kinds of valid TIFF images. When writing, uncompressed images and the compressions zstd and lzma are all I need.

I assume that TIFF can compress the image data with the above mentioned methods and that you need the appropriate libraries to read and write such TIFF files. Is this correct?

What is the role of the raster graphics file formats JPEG and WebP for the TIFF library?

Answer 1

JPEG and WebP are both containers (file format) and lossy raster compression methods.

TIFF supports JPEG compression as a standard, see https://en.wikipedia.org/wiki/TIFF#Compression_2 and related references.

WebP is, just like zstd, an unofficial addition to libtiff. From http://libtiff.maptools.org/v4.0.10.html:

Please note that COMPRESSION_WEBP is self-assigned the id 50001 by the libtiff project and is not officially registered with Adobe since Adobe's registration function is defunct.