3 ms·

This is very interesting. Does anyone know a way to do this without knowing the exact size of the object whose distance you want to measure?

arriu 12y ago
If I were to do this, I'd try the following: First, lets examine what we know. Further objects will exhibit less relative movement then closer objects when looking through a slowly moving video camera (parallax motion). We can reconstruct 3d scenes using more than one image of the same scene from slightly different angles. I imagine your question is for single images rather than multiple images of the same scene. Thus parallax motion will not help us. However, unless the images are taken using a tripod, there will be some kind of micro blur introduced by pushing the "take picture" button on your camera. These blurs can be analyzed. Using the same principal as above, further objects will be less blurred due to the motion. This can be used to reconstruct a 3d scene from a single image. Next, we will likely know the characteristics of our lens and the focus/zoom settings that were used to take the image. Using this, plus the 3d scene from above, we should be able to calculate the distance to any object (recognized or not). (disclosure: I am not an expert in this and do not know if this would work) 𝒆𝒅𝒊𝒕: This may actually work (see research below) http://www.cv-foundation.org/openaccess/content_cvpr_2013/papers/Lee_Dense_3D_Reconstruction_2013_CVPR_paper.pdf http://www.cv-foundation.org/openaccess/content_cvpr_2013/pa... https://www.youtube.com/watch?v=5Le0pxfRo80 https://www.youtube.com/watch?v=5Le0pxfRo80
- thomyorkie 12y ago
  Thanks! Using the accidental motion of the photographer is extremely cool. However, for my purposes I have video that is taken from a camera on a tripod, so I don't think that method will work.

3 ms·

This is very interesting. Does anyone know a way to do this without knowing the exact size of the object whose distance you want to measure?

by thomyorkie 12y ago

arriu 12y ago
If I were to do this, I'd try the following: First, lets examine what we know. Further objects will exhibit less relative movement then closer objects when looking through a slowly moving video camera (parallax motion). We can reconstruct 3d scenes using more than one image of the same scene from slightly different angles. I imagine your question is for single images rather than multiple images of the same scene. Thus parallax motion will not help us. However, unless the images are taken using a tripod, there will be some kind of micro blur introduced by pushing the "take picture" button on your camera. These blurs can be analyzed. Using the same principal as above, further objects will be less blurred due to the motion. This can be used to reconstruct a 3d scene from a single image. Next, we will likely know the characteristics of our lens and the focus/zoom settings that were used to take the image. Using this, plus the 3d scene from above, we should be able to calculate the distance to any object (recognized or not). (disclosure: I am not an expert in this and do not know if this would work) 𝒆𝒅𝒊𝒕: This may actually work (see research below) http://www.cv-foundation.org/openaccess/content_cvpr_2013/papers/Lee_Dense_3D_Reconstruction_2013_CVPR_paper.pdf http://www.cv-foundation.org/openaccess/content_cvpr_2013/pa... https://www.youtube.com/watch?v=5Le0pxfRo80 https://www.youtube.com/watch?v=5Le0pxfRo80
- thomyorkie 12y ago
  Thanks! Using the accidental motion of the photographer is extremely cool. However, for my purposes I have video that is taken from a camera on a tripod, so I don't think that method will work.