R

resize

Provides a menu and status bar to resize the window dimensions to a specific size.

Image Squeezer accepts one or multiple images of any format, converts them into JPG, reduces the quality to 70%, resizes the image to 1280px on the longest side and - if available - compresses it once more with ImageOptim.

Shake off extra weight from videos

Resize/slice/join video file using ffmpeg(x264) with a Gtk+ GUI.

Form Upload and resize image and mail it as attachment with PHP. It uses gd for the image stuff.