Saving VGA still frames without a PC - e.g. memory card VGA frame grab

Hi,

We are looking to capture still images from a 1024 x 768 VGA microscope output. We'd prefer not to have to use a PC, rather we'd like to have a frame grabber that saves the still image to a memory card or a usb stick. The capture would be the result of say pressing a button on the frame-grabbing unit. It doesn't need to be complicated - just a manual capture of a single VGA frame as a jpg / png / etc to some sort of memory card, that can be connected to a PC at a later date.

Please could anyone recommend such a product? We've had a look but companies like Epiphan, require the use of a PC.

Thanks in advance!

Cheers,

Tom.