An Approach to Calculate Depth of an Object in a 2-D Image and Map it into 3-D Space

Abstract

The essence of an image is a projection from a 3-D scene onto a 2-D plane, during which the depth information is lost. The 3-D point corresponding to a specific image point is constrained to be on the line of sight. From a single image, it is very difficult to determine the depth information of various object points in an image. If two or more 2-D images are used, then the relative depth point of the image points can be calculated which can be further used to reconstruct the 3-D image by projecting the image points which includes the depth information as well. This paper presents two techniques namely binocular disparity and photometric stereo for depth calculation and 3-D reconstruction of an object in an image as it requires minimum user intervention.Binocular disparity method requires a pair of stereo images to compute disparity and depth to generate the desired 3-D view whereas the photometric stereo method requires multiple images under different light directions.

3D visualization of 2D/360° image and navigation in virtual reality through motion processing via smartphone sensors

“…where Tx is the base of the eye pair. So, the image is having (X0, Y0, Z0) coordinates values than, the segmented new pair's coordinate can be expressed as below [27].…”

“…Therefore the difference between the horizontal x-axis will be the binocular disparity, D. D=XidealImage -XNewImage (5) Moreover, our eyes are fixated on a point. Depending on it there are some conditions that was needed to be considered while calculating the disparity [27].…”

“…Disparity D, will be zero when the point is at the fixation point Figure 5. Disparity [27] In the figure above, assume that P1 and P2 are the projection of the 3D point P on the ideal image and the new image. Oid and Onew is the coordinate of the images, f is the local length of eyes on the physical environment and Z is the depth map of the image.…”

“…Furthermore, the SGBM algorithm generates the disparity. From the disparity the depth image is generated by given formula [27] Z= f * ( )…”