Superimpose Image on 6D's Screen

[Photografeels]

Hi Ya'll,

Searched around a bit and havent come across this question let alone any answers.

TLDR: Can you take an image from a computer, put it on an SD card then using the Double Exposure feature, overlay the image over a live view preview?

What I'm really looking to do is load in some real estate renders, turn on the Double Expo feature, and use the Double Expo overlay to match perspective and then shoot people that will be superimposed into said renders. Yes I am aware you can match perspective in post, but I would love a way to get the perspective in the ball park in camera.

Ive tried just loading a jpeg onto an SD card and hoping for the best but no such luck. I converted a Jpeg to DNG using Adobe Camera Raw, then changed the DNG to a CR2. Still no such luck. My guess is, since there isn't a preview embedded into the file the camera doesnt know how to display it. I can "see" it in the camera it just says it cant be displayed. Maybe because there's nothing about it in the CTG file? Anythoughts would be greatly appreciated.

Thanks for your help folks,

-N

[Waddizzle]

1.  This would be easier to do in post on a computer.

2.  The camera will not recognize any images that you add to the memory card.

3.  The free image editors out there like GIMP, or PaintDotNet which is far less complicated.

[Photografeels]

I appreciate the response.

I realize that this is doable on the computer, however the whole reason Im looking to do this is to match perspective of two images while I'm shooting. Trying to avoid shooting a series of people and then going to add them to my renders only to realize the perspective was off. 

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Adding to original questions:

At the very least is there any external monitors that can do overlays?

[Waddizzle]

I am no monitor expert. Why not shoot the shot, get it close, and then tweak the camera position for the rendering?