DynPicWaterMark adds dynamicaly a watermark to your posted images on display time (no changes on original picture) . You can configure if it marks all your images or just the ones you set on post usage time. Watermark Position can be configured by post usage or a general default. You can change the watermark whenever you want without having to process all images and upload. It can be applied to all your current posts. Watermarks size can be configured to be: a % of picture height or width; a fixed Height or width; the watermark original imge size.
