A way to take long horizontal (scanner) images quickly (nearly instant)

Question

Is there a way to take long horizontal images using techniques similar to a scanner NEARLY INSTANTLY

In other words I want to be able to point a camera out the left or right window of my car, drive a few blocks in one direction, and 30 seconds later post a picture that is an orthographic projection of the view out the side of the car for that 30 seconds. The same way I can rotate the phone and a few seconds later post a panorama. Anything slower is not answer to this question (manually taking 500 to 1000 pictures and loading them into some software over hours is not a solution).

Such an solution would either take video or use a live camera and using motion detection pull out a center column of each frame to build an indefinitely long image.

The difference between this and panorama is panorama works by rotating the camera. This works by moving the camera in one direction so imagine putting the camera facing out the side of a car or train and making a long flat projection photo of an entire city block.

I know I could do this in Photoshop potentially but it would be extremely tedious as only a small column from center of each image can be used otherwise there would be perspective distortion issues so I'm wondering if there are other solutions.

Trying to make it clearer the result of the technique I'm looking for would generate an image with no horizontal perspective. Imagine you just try to take a picture of a bookshelf using 2 pictures, one for the left 60%, another for the right 60%. They overlap in the middle. In both images you'll get perspective. You'll see the sides of the bookshelves perspecting toward the center and you see that panorama software can't fix this problem.

On the other hand if you took 1000 images and only took the center 1% from each one you'd get a flat image, at least in the vertical plane. Because stitching that many (or far far more) images is way too much work, ideally you want a solution that using a live camera only takes 1 vertical pixel column from each image, saving on the storage and processing costs.

This is how smart phone cameras take panoramas (at least iphone). It only takes thin columns as you rotate the camera. Unfortunately it uses the compass sensor to know that you're rotating. There is no position sensor accurate enough to know you're sliding the camera left to right so instead you'd need to use image motion detection tech.

Answer 1

This is how smart phone cameras take panoramas (at least iphone). It only takes thin columns as you rotate the camera. Unfortunately it uses the compass sensor to know that you're rotating. There is no position sensor accurate enough to know you're sliding the camera left to right so instead you'd need to use image motion detection tech.

You may be mistaken. My smartphone (Xiaomi Note 7) doesn't need a rotation since I just took a linear panorama of kitchen appliances by dragging it along the edge of my kitchen counter. How it works is anyone's guess, it possibly looks at some features of the image and how they move across the frame. Of course when you are standing, the only way to have features of the image change sufficiently fast is to rotate the camera, but if you are close you can just walk as I did.

Looking at the result show the limits of the method, the camera cannot tell the instant speed, so unless you maintain a very steady speed the image is likely to be shrunk or stretched at random horizontally, so I doubt you can use the technique in a car in traffic.

Experiment: "scanning" a magazine cover using the panorama mode (the original picture is 14000 pixels high):

Answer 2

As noted in a comment, this is still a panorama. I'm going to leave arguing that point out of my answer in the assumption that the question will eventually be edited to fix that.

While I'm not aware of any phone apps, the Hugin program commonly used for panoramas and other image stitching on Linux can do this easily. One key term you might search for is "linear panorama" — here's a tutorial I found by searching for that.

To eliminate the (horizontal) perspective distortion you are concerned with, do some combination of these three things:

1. Shoot with a narrow (long focal length) lens.
2. Only move a small amount between shots so there is a lot of overlap.
3. Pre-crop your images to narrow vertical strips.

I haven't done this at particulary large scale — point 3 may get you easier results, although given enough time and compute power, and the right settings, not doing that and trusting point 2 will be sufficient.