PTLens is described as 'Software that correct lens pincushion or barrel distortion, chromatic aberration, vignetting, and perspective in normal and fisheye lenses' and is an app. There are more than 10 alternatives to PTLens for a variety of platforms, including Windows, Mac, Linux, BSD and KDE Plasma apps. The best PTLens alternative is GIMP, which is both free and Open Source. Other great apps like PTLens are showFoto, DxO ViewPoint, Ultimate Paint and ShiftN.
RealWorld Photos is an free portable photo editor for Windows. Retouch photographs and batch process images in an easy-to-use editor. Perform lossless retouching, watermarking and other operations on .jpg images.
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