''1. Introduction''

Due to the need to get rid of libtiff, I needed to write tiff images without it and started to write a simple tiff RGB image writer in tcl using the tiff v6.0 specification documentation.
Afterwards I transfered the functionality into C++ and I was happy to have no libtiff anymore.

The reasons to get rid of libtiff were, that we only needed to write tiff RGB images and that we have 5 platforms to support - 4 UNIX platforms with 32/64bit, ... - so we don't wanted to built more external libraries than needed.

The tiff package provides following functionality:

   tiff2raw:   this proc reads a TIFF image file, returns its header, its first image file directory containing all needed information to handle the returned raw data from the TIFF image file. The raw data is not decompressed or decoded. So if a LZW compressed TIFF image file is read, the raw data contains the LZW data.

   raw2tiff:   this proc takes raw data, the width, height, horizontal and vertical resolution, a description to write a TIFF uncompressed RGB image file. So the raw data must be plain RGB data.

   dumpTiff:   this proc dumps a TIFF image file by writing the information from the image file header and the first image file directory to a channel or a file. Optional the proc saves the raw data into a file too.

   photo2raw:   this proc converts data given by the data command of a tk image (type photo) object into plain RGB data.

   photo2tiff:   this proc converts a given image (type photo) into a TIFF uncompressed RGB image file, using the given description and the horizontal and vertical resolution.

   tiff2photo:   this proc converts if possible a TIFF image file into a tk image (type photo) object. Only uncompressed RGB, RGB palette, Grayscaled and Black/White image files are accepted.