• PTLens is software that corrects lens pincushion/barrel distortion, vignetting, chromatic aberration, and perspective. The following are supported: Standalone application (JPEG, 8 or 16-bit TIFF); External editor for Lightroom (JPEG, 8 or 16-bit TIFF); Plug-in for Photoshop (any 8 or 16-bit RGB image).

Multiprocessing

Modern computers often have processors that contain more than one core. Each core can work in parallel to handle computationally intensive tasks. To improve the performance of PTLens on your system choose Tools > Options and specify the number of threads on your system.

The following table illustrates the time it takes to process a 24MP (6000x4000 pixel) image on a system with a processor that has 4 cores and supports, via hyperthreading, 8 threads. The image was corrected for barrel-pincushion distortion and all sliders for Perspective, Vignetting, and Chromatic Aberration were enabled.

Processors | Seconds

1 | 10
2 | 6
4 | 4
8 | 3
16 | 3

• When only correcting for distortion it took less than 1 second when utilizing 8 threads. Specifying the correct number of processors improved performance by a factor of three. No benefit is gained by specifying more processors than supported by your architecture. There was no penalty either as the overhead for extra threads is minimal.