This contribute image watermark as opencart plugin to extend the opencart avaibility to auto generate watermark image to all product page thumbnail.
Easy enabled/disabled watermark at admin panel
Easy to set the require image size before trigger the watermark features
Easy control to show watermark at selected position (topright, top left, center,bottomright, bottomleft)
1) Unzip and upload the contents to the root directory of your OpenCart installation
2) Login to administrator page, Extension-> Modules -> Watermark Image -> Install
3) Set the watermark to show on the image that appear to meet the image size requirement.
Default : 300 x 300 meaning image width > 300 and height > 300 will have watermark display at thumbnail
4) Choose the require setting and click Save.