Hello
I very new to Arduino so far i've only made a automatic fish feeder with arduino..\0/
I was wondering if its possible to capture a still image from a composite video signal and save it to a SD \ Usb stick as a Jpeg or some other picture format. 
It is possible, but not really worth the effort - it takes a long time and both the spatial and greyscale resolution will be poor.
Example here
JPEG is very difficult to achieve, except maybe on a Mega or Due
Thank you for the quick response, do you have any suggestions on where could look to find something that would suit my needs? I cannot use a computer for this task. The less software the better.
Using a composite video signal is possible but it is a quie complex circuit involving 50 or so chips.
When you say you can not use a computer what do you mean?
This sounds like the sort of thing you want to use a Raspberry Pi on, although not using a composite video but a very cheap web cam or the Pi's own camera.
Sorry, I missed the composite requirement - the Video Experimenter example is monchrome.
Well iam trying to add this function to a video system that already exists, that captures video over to a USb stick, And i've made it very easy to operate adding a OS to it would complicate things very quickly and also add alot of new ways that the system can crash
Well i am trying to add this function to a video system that already exists, that captures video over to a USb stick,
In that case I am not sure I understand what you want to do. What is this already existing system? Is there a composite video output? Any links to it?
Custom video system, its a 12v Camera that sends a composite signal into a video splitter, from video splitter to a composite recorder -> Usb stick ( Like a gamerecorder for Xbox etc ) and from the video splitter to a tv.
I was hoping to add a a function that would take a picture of the current frame and save it as a jpeg or something on a separate SD card\Usb stick.
and save it as a jpeg
You can probably forget that bit. Saving as a jpeg is way too complex for an Arduino.
The conversion from a composite video signal is possible, I have several that I designed in the 80s. However, they will all produce data faster than you can write it to an SD card.
This is one - 8 levels of grey and a resolution of 160 by 256, taking about 3.5 seconds to read in an image.
Words here:-
http://www.doc.mmu.ac.uk/STAFF/A.Wiseman/Acorn/BodyBuild/BB87.html
Pictures attached.
