I have imported thousands of images using the Standard preview rendering.
What this means is that when I zoom into an image to view it full size, it takes a while to process and then display the image.
What I should have done is import them as 1:1 preview rendering. This will let you zoom in immediately without any processing.
How can I re-generate the image previews as 1:1 ?
(I do not wish to re-import them as I have numerous meta-dat attached to them)