Photopus Pro - Photopus Pro is an easy to use batch image processing to simplify the process to convert, add watermarks (text and image), resize, transform, touch-up, rename, and apply effects to your digital images.
Blender - Blender is the open source, cross platform suite of tools for 3D creation.
GraphicConverter - Graphic Converter for Mac and Windows, can converts image formats BMP, JPG, GIF, ICO, PNG, TIF...
FreeCAD - An open-source parametric 3D modeler
Batch Image Converter - Convert multiple images, photos, and pictures between 30+ formats: JPG, PNG, GIF, TIFF, BMP, JP2, J2K, TGA, PSD, RAW, DDS, PNM, WMF, ICO, SGI, HDR, LBM
meshmixer - meshmixer is an experimental 3D modeling tool for making 3D mashups without too much hassle.