DVDVideoSoft Image Convert and Resize - Free Image Convert and Resize is a compact yet powerful program for batch mode image processing.
Adobe Photoshop - Adobe Photoshop is a webtop application for editing images and photos online.
Batch Image Resizer - Resize, crop, shrink, flip, exif-rotate, convert, enhance, process multiple pictures and photos with professional software! 120+ Actions, 30+ Image Formats
GIMP - GIMP is a multiplatform photo manipulation tool.
Ralpha Image Resizer - High-speed image batch conversion tool
Affinity Photo - Affinity is the imaging and design suite for creative professionals exclusively for Mac.