pixel by pixel overlay card

[danstrider]

Here's a question for an AP application ....

In taking live-video, I'd like to put a grid overlay onto the video being transmitted to the ground. This grid combined with an mount that always looks straight down will give great information on ground target location and orientation. I already have a GPS antenna that will connect to a gumstix card (www.gumstix.com) to give location and altitude information. The piece I lack is an overlay card that will do pixel-by-pixel overlay. I'm not all up and up on the computer side of things; I'm working with a few friends to set this up ... we're not sure where to find an overlay card for this application. Anyone know of a small and light overlay card that you can choose which pixels to color.

Thanks for any help!
Dan

[Bob Blackburn]

Why can't you add the grid to the video on the ground?

If it is because you want the grid to move over the ground with the plane yhen you cant add it to the video even at the plane as it will have the same effect.

But

If you have a grid the camera looks through then you will have the correct effect. It may be possible to remove the lens and place the grid inside the camera in front of the ccd chip.

[vintage1]

Ohmigosh. We used to build this stuff years ago - a friend and I.

You need something used in small quantities by video studios, and therefore impossibly expensive.

Don't give up, but be prepared for disappointment.

[Mr.RC-CAM]

Can you clarify the grid details? Do you only need a series of carefully spaced fixed dots or graticuled lines? When you say you need to manage it on a pixel basis, what resolution are your pixels?

A rendered drawing of your idea might help.

RC-CAM

[FlyRC4Life]

Hey, I like input! Thanks guys!

Well, let me go ahead and fend off the grid inside the lens. The flight altitude will change, and I'd like to keep the grid at a constant scaling.

Adding the grid to the video on the ground is difficult without sensors sending information back to the ground..... But, I am asking around about using some other sensor data coming to the ground. I'll post again in a week when I know the possibility of using that data.

Vintage! Where can I find this impossibly expensive "something" and I really really would like to persue it! I'm prepared to be disappointed, but hopeful that I can make it down the road a bit before I am disappointed. More info please :-)

Thanks guys,
Dan

[ALtitudeap]

try www.HittConsulting.com he has an overlay that will do just about anything.

[Gary Warner]

Again, as asked before, can this grid be used after the fact?

If so, you most likely have what it takes.

Import your video to a PC.

You can do one 2 different things:

If wanting the video overlay as the video plays you can use PaintShop (or whatever) to draw a grid. Save the image. In the video player (if it's overlay capable) mix the two images with the grid having the desired scale and transparency.

If wanting to evaluate frames (for scale reference) capture the frame to look at and import it into PhotoShop. Again, make and import a grid. Overlay one on the other with the desired scale and grid transparency.

This is NOT what you were asking about, but it may fill your need.

Gary
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[MatC]

"High Resolution 256 x 192 pixels" ... hmmm. Looks like their card is designed to overlay a static image from eeprom, rather than a high res moving image.

I'm actually thinking of building a tv resolution overlay board at some point. It isn't a trivial project, but shouldn't be too expensive. It would have direct pixel writing of course.
Dan: how do you plan to cope with non-flat ground? How do you work out your orientation/rotation? How do you cope with your camera angle changing as your plane banks? Just curious :)
If you're a bit of a tinkerer, you can build an overlay board with a pic chip (to generate the output), a phase locked loop to lock to the lines, voltage controlled oscillator to generate pic freq from the lines, and a sync separator to give you h and v sync.