Image Tools is simple, free and powerfull mass image resizer, converter, cropper, flipper/rotater, optimizer and watermarker.

Features:

Windows Vista/7 full compatibility

Good memory managment for processing big amount of big images

BMP, GIF, JPEG, TIFF and PNG image formats support

Multicore processing support - extreme perfomance

Variable quality for output (optimizing)

Color channels filtering

Internal benchmarking tool

Able to process indexed pixel format images

Image Tools programm also can calculate image color histogramm, which can be used (later) for checking images for uniqueness.