Alien Skin Software's BlowUp is a ultra-high-quality and pretty handy nondestructive image zooming tool released as Adobe Photoshop/Lightroom's filter plugin and standalone application. Its powerful features even leave many similar software (such as BenVista PhotoZoom Pro, Reshade Image Enlarger, Inpixio Photo Maximizer Pro...) in the dust!

Reshade Image Enlarger (alias: Reshade Image Resizer) is a picture magnifier application, which provides the high-quality image enlargement effect. That's you can change the picture size yet avoid the usual fuzzy, serrated edge, intensification and other issues at the same time.