Predominantly a photo viewer and converter, IrfanView is a useful freeware tool to have installed on any Windows PC. If installed with its optional Plugins it can read almost every graphics, audio, and video file format known to man (and there are a lot).
It also offers many graphic image editing features.
To read The Portable Document Format (PDF) is a file format developed by Adobe to present documents in their original formatting, independent of software, hardware, and operating systems. PDF files can contain text, graphics, links, and buttons, form fields, audio, video, and format it needs Ghostscript for Windows (32 bit) to be installed. (Do NOT install the 64-bit version as IrfanView will NOT detect it.)
It can batch convert between formats, so enhanced (.DjVu) viewer images downloaded from http://www.findmypast.co.uk can be converted to .png or .jpg format for use in Family Historian.
With the Plugins it can merge multiple files into a single file such as a multi-page PDF document. See File > Thumbnails > File > Start Multipage-PDF dialog or Options > Multipage Images.
Optical Character Recognition (OCR) is supported via the KADMOS Plugin. See Options > Start OCR.
Visit http://www.irfanview.com for further details.
Revised by tatewise (03/11/10)Link: IrfanView