Igor,
The following are portions of the leadtools OCX help file that describes TIFF support:

LEADTOOLS reads and writes several TIFF formats that do not require an LZW license.
TIFF is a tag-based file format designed to promote universal interchanges of digital image data. Because TIFF files do not have a single way to store image data, there are many versions of TIFF. LEADTOOLS supports the most common TIFF formats. The usual file extension is TIFF for single-image files, and MPT for multipage files (which can contain many images).
LEADTOOLS can read and write TIFF files that use RGB, CMYK, or YCbCr color space. LEADTOOLS can also read and write files with PackBits compression.

LEADTOOLS can also read and write files with Lossless JPEG compression for 8, 12, and 16-bit grayscale and 24-bit color spacing.
You can read the following bits per pixel, without regard for the color space: 1, 2, 3, 4, 5, 6, 7, 8, 16, 24, 32.
You can write the following bits per pixel, with RGB color space: 1, 2, 3, 4, 5, 6, 7, 8, 16, 24, 32.
You can write the following bits per pixel, with CMYK color space: 24, 32.
You can write the following bits per pixel, with YCbCr color space: 24.

You can read and write 12- bit grayscale. (Medical Express editions only)
You can write 16- bit grayscale. (Medical Express editions only)


LEADTOOLS reads and writes the following LZW-compressed formats. Note that these formats require a separate license, as explained in LZW License Instructions.

GIF. This is the Graphics Interchange Format created by CompuServe for storing and exchanging color raster images.

You can read and write the following bits per pixel: 1, 2, 3, 4, 5, 6, 7, 8.

Animated GIF. This is a multipage GIF format that can be played as an animation by displaying the images sequentially. LEADTOOLS lets you create and play the animations.

You can read and write the following bits per pixel: 1, 2, 3, 4, 5, 6, 7, 8.

TIFF LZW. These files use the Tagged Image File Format with LZW compression. LEADTOOLS can read and write TIFF files that use RGB, CMYK, or YCbCr color space.

You can read the following bits per pixel, without regard for the color space: 1, 2, 3, 4, 5, 6, 7, 8, 16, 24, 32.
You can write the following bits per pixel, with RGB color space: 1, 2, 3, 4, 5, 6, 7, 8, 16, 24, 32.
You can write the following bits per pixel, with CMYK color space: 24, 32.
You can write the following bits per pixel, with YCbCr color space: 24.
You can write 16- bit grayscale. (Express editions only)

Hope This Helps