iMarker - It can mark text in images by highlighting the important parts using the mouse pointer, similar to manually color marking. Images from websites and screenshots can be quickly pasted and edited.
Veqa Image Marker - Veqa Image Marker is a PHP tool to mark Web images on the fly. Features 40 mark presets, X/Y offset positioning, opacity, watermark security, and more. Supports JPG, GIF (and animations), PNG, BMP; and GD, ImageMagick, MagickWand.