Do you need the picture in JPEG format?
"Serial": Back when LEDs were new, I designed an number of "frame capture boards" that grabbed video (VGA and composite) and converted it to a format (digital) that a computer can understand. (not JPEG) I understand the "analog input" of LCD monitors. There are/were ICs on the market that convert analog video to digital. (8,9 or 10 wires for RED and wires for GREEN and wires for BLUE) The digital output has several formats. (24 wires + 2 syncs + clock) The clock is running at the video rate. OR 8 wires + 2 syncs + clock where the clock is running at 3x the video rate. Depending on the clock rate, video changes every 100nS, there is no FIFO. You can not miss any data.
Now that I think about, there is a one frame FIFO IC that I used some times. It has 9 data lines in and 9 data lines out. Clocks at speeds up to 35mhz. Can hold one picture. It really helped with CPUs that could not process video at full speed.