New to Alamy but am a long-standing video journalist, filming news events in 4K quality. My question: Would it be possible to basically take a screenshot (ie. cut and crop a JPG from a .mov or .mp4 video) of any interesting 4K video footage and upload the resulting JPG to Alamy? Would there be any technical reason why this would not be possible (maybe in terms of size of image)? I have a Macbook Pro though no photo editing software at present - so would need some way to add IPTC data. Thank you.