I can no longer read some old PDD files of scans of photographs I took on film a number of years ago. I have downloaded Total Image Converter Version 1.0 from CoolUtils.com to convert them to JPeg and Tiff files to be able to access the images. Every conversion brings up a black screen with the words "Photoshop 3 is required to open this file". Curiously, this screen comes up when I attempt to open it with Adobe Photoshop Album Starter Edition 3. Julian Amos
PDD is or used to be a standard file format for files created in Adobe PhotoShop, so your best chance of reading these files is to use your original program, if it's still available, or another program from the same family. PhotoShop is expensive but you may know someone who has a copy, and will load the PDD files and save them in a more common format, such as JPeg. PDD is a layered format and files can become corrupted, so there are also programs designed to rescue valuable images. Examples include Advanced PSD Repair (www.psd-repair.com), which costs $149.95, and PhotoshopRecovery (www.officerecovery.com/photoshop/) which costs $99.
Because there are hundreds of image file formats, many programs will convert between them. The first ones to try are Irfan View (www.irfanview.com), XnView and Nconvert (http://tinyurl.com/4y64r), and both are free for non-commercial use. These are still worth a go, but if Total Image Converter (www.coolutils.com/TotalImageConverter) can't read the files, I would not hold out too much hope. It could be quicker and easier to go back to the original images or have fresh prints made for rescanning.
In general, it's a good idea to avoid saving important data in proprietary file formats or formats supported only or mainly by one company. These have their uses, but it's always worth saving a back-up copy of a file in a different, widely supported format. For example, save a JPeg as well as a PDD or PSD file, save an RTF or HTML file as well as a DOC file in Microsoft Word, save a CSV file in a database, and so on.
The internet answer to the image file format problem is PNG which stands for Portable Network Graphics or, recursively, PNG's Not GIF (www.libpng.org/pub/png/). However, it has not been as successful as expected. PNG is lossless so file sizes are larger than "lossy" compressed formats such as JPeg.
