ImageGear for C and C++ on Windows v19.1 - Updated
Warp Effects
User Guide > How to Work with... > Image Processing and Cleanup > Special Effects > Warp Effects

The IG_FX_cylinder, IG_FX_parabola, and IG_FX_sphere functions perform a point-to-point stretch of the image to give a warping effect.

Original

Cylindrical Warp Effect

Parabolic Warp Effect

Spherical Warp Effect