Mapping image on spherical surface - julia

Question

In simple words i need to map a image to be use in a spherical surface. I being trying to do this for several hours. searching in google I din't find any proper solution (explained for dumb people).
I thinks the code from this link:
https://www.codeproject.com/articles/19712/mapping-images-on-spherical-surfaces-using-c is what i need. but (i think everything is alright) can make it work in Julia.
This is my code so far:
image = brightNoise(height,width,seed,rand=true)
arr = Array{Float64}(height,width)
function MapCoordinate(i1, i2,w1,w2,p)
return ((p - i1) / (i2 - i1)) * (w2 - w1) + w1
end
function Rotate(angle, axisA, axisB)
return axisA * cos(angle) - axisB * sin(angle),axisA * sin(angle) + axisB * cos(angle)
end
phi0 = 0.0
phi1 = pi
theta0 = 0.0
theta1 = 2.0*pi
radius = 50
arr = Array{Float64}(height,width)
for i= 1:size(image)[1]
for j= 1:size(image)[2]
#map the angles from image coordinates
theta = MapCoordinate(0.0,width - 1,theta1, theta0, i)
phi = MapCoordinate(0.0,height - 1,phi0,phi1, j)
#find the cartesian coordinates
x = radius * sin(phi) * cos(theta);
y = radius * sin(phi) * sin(theta);
z = radius * cos(phi);
#apply rotation around X and Y axis to reposition the sphere
y,z=Rotate(1.5, y, z);
x,z=Rotate(pi/2, x, z);
#plot only positive points
if (z > 0)
color = image[i,j]
ix = floor(Int64,x)
iy = floor(Int64,y)
arr[ix,iy] = color
println(ix,iy)
end
end
end
The image is just a black and white noise generated in Julia, i need to wrap a sphere with it.

Answer 1

I have little idea what your code is doing, but fixing some of the indexing issues gives something that might help you get started. It looks like it's doing something spherical, anyway...
using Images, FileIO
mandrill = load(mandrill.png")
height, width = size(mandrill)
arr = colorim(Array{Float64}(height, width, 3))
function MapCoordinate(i1, i2, w1, w2, p)
return ((p - i1) / (i2 - i1)) * (w2 - w1) + w1
end
function Rotate(angle, axisA, axisB)
return axisA * cos(angle) - axisB * sin(angle),axisA * sin(angle) + axisB * cos(angle)
end
phi0 = 0.0
phi1 = pi
theta0 = 0.0
theta1 = 2.0 * pi
radius = 200
for i = 1:size(mandrill, 1)
for j = 1:size(mandrill, 2)
# map the angles from image coordinates
theta = MapCoordinate(1.0, width - 1, theta1, theta0, i)
phi = MapCoordinate(1.0, height - 1, phi0, phi1, j)
# find the cartesian coordinates
x = radius * sin(phi) * cos(theta)
y = radius * sin(phi) * sin(theta)
z = radius * cos(phi)
# apply rotation around X and Y axis to reposition the sphere
y, z = Rotate(1.5, y, z)
x, z = Rotate(pi/2, x, z)
# plot only positive points
if z > 0
color = mandrill[i, j]
ix = convert(Int, floor(x + width/2))
iy = convert(Int, floor(y + height/2))
arr[ix, iy, :] = [color.r, color.g, color.b]
end
end
end
save("/tmp/mandrill-output.png", arr)
run(`open /tmp/mandrill-output.png`)