I need to perform Gram-Schmidt pan-sharpening, I don't have access to ArcGIS or ENVI so have been using QGIS. Is there any plug-in or similar capability that is available to perform Gram-Schmidt pan-sharpening in QGIS? If not, is this possible in any other open-source software?
To summarize the comments above at the moment the is no such functionality in QGIS. You could try to implement your own plug-in to perform this task by using this scientific paper: How to pan-sharpen images using the Gram-Schmidt pan-sharpen method-a recipe