I am not a pro with Adobe products, but all of the perspective correction tools I have seen in Photoshop or Lightroom seem to involve stretching the top part of an image until the sides are straight. What I am interested in is taking a photograph of a building and converting it to what would be the equivalent of an architectural elevation. This would involve straightening the image, but also stretching it vertically. I imagine this would involve calculating the difference between the bottom and top lengths of the skewed image and using that to calculate how foreshortened the image is, which in turn would allow for a calculated and graded stretching of the image. Imagine a brick wall 20 feet wide and 20 feet tall. All brick courses are the same height. But in a photo taken from the ground, the courses at the bottom would be the right height but those higher up would appear shorter, due to the perspective. At the same time the wall would taper inward in the photo as well. There must be a way to use a measurement of that taper to determine how much the photo should be stretched at each course of bricks. (or presumably each row of pixels in the image) At the bottom it would be negligible, and would increase more as you go up. If done properly the result would be a square image with all of the brick courses being the same height. Some algorithm would have to be created to allow this, but it seems mathematically logical... As an architectural historian, a tool like this would allow me to use images to make approximate vertical measurements of building elements.
1
Reply
AdChoices