Stacked maps

Stacked MaPs (SMP) is a proprietary file format to store a series of images. In EBSD-Image, this file format is used to quickly access diffraction pattern images. This offers a solution to store the thousands diffraction pattern images output by HKL Channel 5 or TSL OIM.

This file format was created with the following reasoning in mind:

• Store a large quantity of images inside one file. This eliminates the operating systems’ problem to list a folder with a large quantity of files.
• Easier to move all the images at once. Great for backup.
• Random access of maps in the SMP file without loading the whole SMP file in memory.
• Quickly load map from SMP file. No decompression required.

Benchmarking

On an Intel Xeon 3 GHz computer (3 GB of RAM, 7,200 rpm SATA hard drive) with the Microsoft Windows XP operating system, it takes one minute to browse a folder containing 50,298 images. The transfer of these files to a portable magnetic hard drive via a USB 2.0 connection takes just over 18 minutes. On the same computer described above, the inclusion of 50,298 images into a SMP file takes approximately 2 minutes and 30 seconds. The real advantage comes when transferring the SMP file to another media format: it took one minute to copy the SMP file to the same portable hard drive.