For barrel and pincushion distortion, lens-correction software typically aims for an ideal rectilinear projection for that focal length: a model where straight lines in the scene remain straight in the image. So the target is not “what looks good” or “what the eye sees,” but a calibrated geometric correction based on lens behavior.

These corrections usually do not analyze the picture content and guess. Instead, software uses a lens profile or user-set parameters derived from calibration, often by photographing test targets. The profile describes how that specific lens behaves, often depending on focal length and optical centering, and applies equations to reverse the measured distortion.

Different software may vary in how profiles are implemented, but the general goal is the same: correct optical aberrations toward how the image would look if the lens had ideal geometry. Because the image is remapped, the corrected result may be cropped slightly and the effective field of view can change a bit.