Thumbnail and Watermark

This is a class that can process an image on the fly by either generate a thumbnail, apply an watermark to the image, or resize it.
Autodetect GD 1 and GD 2, auto-fitting, scaling, calculate quality factor for a specific file size, suport bicubic resample algorithm.

The processed image can either be displayed in a page, saved to a file, or returned to a variable.

It requires the PHP with support for GD library extension in either version 1 or 2. If the GD library version 2 is available it the class can manipulate the images in true color, thus providing better quality of the results of resized images.

Features description:

- Thumbnail: normal thumbnail generation
- Auto-fitting: adjust the dimensions so that the resized image aspect is not distorted
- Scaling: enlarge and shrink the image
- Format: both JPEG and PNG are supported, but the watermark image can only be in PNG format as it needs to be transparent
- Autodetect the GD library version supported by PHP
- Calculate quality factor for a specific file size in JPEG format.
- Suport bicubic resample algorithm