line of sight

is there a nice way to get the line of sight from one pixel to the remaining pixels in an image? like if I had a binary image of a 5-pointed star, each point would only have line of sight to nearby arms in 2-D. or in 3-D, if there was a hemisphere surface, the apex of the hemisphere would have line of sight on nearby pixels, but not the outermost edges because of the curvature of the hemisphere (like the horizon of the earth). thanks

[Walter Roberson]

Do you have the mapping toolbox? There is a function in there that does this for 3D. Unfortunately I do not remember the function name.

Answer 1

[Walter Roberson]

Found it: viewshed() from the mapping toolbox.

http://www.mathworks.com/matlabcentral/answers/37368-max-coverage-camera-placement